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Preface
You all are aware that “Metrology” is the science and application of measurement, embracing both
experimental and theoretical determinations at any level of uncertainty for the purpose to be fulfilled
in various fields of science and technology. Now days, the role of Metrology has become more
significant to the frontier areas of defense, space, medical application and then down to day to day
needs of human beings.
Metrology across the globe is facing new challenges day in and day out due to ever increasing
expectations and sophistications of mankind needs and so the old, dull subject has now turned out to
be interesting and challenging; integrating various disciplines, complimenting one another, to face the
daunting task of best quality, small size and cost effective products.
We are glade to inform you that the Precision Engineering & Metrology Group of CSIR-
CMERI is organizing this National Conference during 25th – 27
th Feb 2015 at our Institute which will
have unique opportunity to meet and discuss between technocrats and doctors, academician and
professional engineers, entrepreneurs and corporate executive, industrialist, calibration and testing
house personnel and all intellectual people.
A key objective of AdMet-2015 vision is to identify emerging trends and provide strategic
directions in the field of advanced metrology. Good number of papers submitted by calibration and
testing engineers, quality assurance people, accreditation officers and basic researchers are included in
this book. We have twelve invited speakers and one plenary talk from non other than Dr. Kamal
Hossain, Director NPL, Tedington UK ; who all have kindly consented to deliver state of art lectures
during these days.
We would like to place on record our deep appreciation to the authors, reviewers, organizing
committee members and sponsors for their support, whole hearted cooperation and active
participation in the conference to make it a grand success. Special thanks go to President, Vice
President, General Secretary, Jt. Secretary, Treasurer of MSI -HQ and Director CSIR-CMERI for
supporting and guiding the local organizing committee.
Editors
Ranjan Sen
Samik Dutta
Content / List of Papers
Proceeding of AdMet2015
Preface
Message from President of India
Message from DG, CSIR
Book of Abstract
AdMet 2015 Programme Schedule
Detail of Sessions
Sl Paper No. Paper name Authors name Affiliation
Health Care
1 HC-1 Quantitation in Routine Microbiology Testing Dr. Bhaskar Narayan Chaudhuri Fortis Hospitals,
Anandapur, Kolkata
2 HC-2 Point-of-Care – Coagulation Testing: An Insight Dr Sugat Sanyal, Dr Rajat Mukherjee Peerless Hospital,
Kolkata
3 HC-3 Burden of Particulate Matters in Punjab due to Agriculture Crop
Residue Burning Seasons Affecting Health of School Children
Sachin Gupta, Ravinder Agarwal and
Susheel Mittal
Thapar University,
Patiala
4 HC-4 Metrology for Safety, Environment and Public Health Prabhdeep Singh Sandhu and Govind
Swaroop Pathak
NIT Durgapur
5 HC-5 Guidelines for Measurement of Mass in Pharmaceutical Laboratories Tripurari Lal CSIR-NPL
6 HC-6 Measurement and Analysis of Key Anatomical Parameters in Cervical
Spine Area of a Representative Sample of Indian Population by using
Computerized Tomography
Partha Sarathi Banerjee CSIR-CMERI
7 HC-7 Measurement Technique of Osteological Parameters of Femur Palash Kumar Maji, S. K. Mandal, A. K.
Prasad and S. Karmakar
CSIR-CMERI
8 HC-8 MIC – Dilutions and Dynamics Indranil Roy, Dr. Rajat Mukherjee SRL
9 HC-9 Molecular Interactions of Cyclodextrin Molecules with 5-
Enolpyruvylshikimate-3-Phosphate Synthase as a Tool for Biosensor
Applications
R. Navanietha Krishnaraj and Sudit
Mukhopadhyay
NIT Durgapur
10 HC-10 Molecular Docking and UV-Visible Spectroscopic Investigation of Anti-
Cancer Drug Nimustine Interaction with Calf Thymus DNA
Deepti Chadha, Shweta Agarwal and
Ranjana Mehrotra
CSIR-NPL
Content / List of Papers
Time & Frequency
11 TF-1 Achieving higher quality factor of a helical resonator by optimizing its
impedance
S. Panja, N. Batra, A. Rastogi, J. Thangjam,
S. Yadav, S. De, and A. Sen Gupta
CSIR-NPL
12 TF-2 Ion trap design for the optical frequency metrology at CSIR-NPL, India S. De, N. Batra, A. Rastogi, J. Thangjam, S.
Yadav, S. Panja, and A. Sen Gupta
CSIR-NPL
13 TF-3 A Novel Technique for Precise Phase and Frequency Measurement Aishik Acharya, P. Arora, S. Yadav, S.
Majhi and A. Sen Gupta
CSIR-NPL
14 TF-4 Current Updates on Primary Frequency Standards at CSIR-NPL, India P. Arora, A.Acharya, V. Bharath, S. Yadav,
A. Agarwal and A. Sen Gupta
CSIR-NPL
15 TF-5 Development of VCO based Drivers for AOM and EOM J. Thangjam, N. Batra, A. Rastogi, S. Yadav,
S. De, S. Panja and A. Sen Gupta
CSIR-NPL
16 TF-6 Instrumentation for Atomic Clock Experiments A. Roy, A. Rastogi, N. Batra, J.Thangjam,
A. Acharya, S. De, P. Arora, S. Panja and
A.Sen Gupta
CSIR-NPL
17 TF-7 Indigenous Discharge Lamps for Rb Atomic Clocks Ashish Agarwal, Jayenta S Thangjam and A
Sen Gupta
CSIR-NPL
18 TF-8 Analogue Modulation Measurement Biswanath Mondal ERTL(E)
Electro Technical
19 ET-1 Traceability of Precision HV Resistive divider by Binary method K. B. Ravat CSIR-NPL
20 ET-2 Evaluation of Four-Terminal-Pair Air Capacitance Standards at CSIRNPL Satish, Babita and A. K. Saxena CSIR-NPL
21 ET-3 Measurements of UV-A Radiation and Hazard Limits from Some
Types of Outdoor Lamps
Essam El-Moghazy, Alaa–Eldin Abd-
Elmageed and Sameh Reda
National Institute for
Standards (NIS),
Giza, Egypt
22 ET-4 Performance Analysis Study on the Calibration Data of Frequency
Counter
Archana Sahu, Bijendra Pal, Saood Ahmad,
P.S. Negi & V.N. Ojha
CSIR-NPL
23 ET-5 Effect of Burden on Potential Transformer M.K. Tamrakar, L. Sridhar, Shrikrishan and
M.A. Ansari
CSIR-NPL
24 ET-6 Analysis of the Stability of the Zener Based Reference DC Voltage
Standard
Sandhya M. Patel, Anish M. Bhargav and
V.N. Ojha
CSIR-NPL
25 ET-7 Development of LabVIEW Based Automation Setup to Analyze Insertion
Loss of RF Cable for Quantum Voltage Metrology
Anish Bhargav, Sandhya M Patel, Saood
Ahmad, P.S.Negi and V.N.Ojha
CSIR-NPL
26 ET-8 Power Calibration System (PPCS)
A Primary Standard of AC Power & Energy
M. K. Mittal, J.C.Biswas, K.P.S.Yadav,
A.S.Yadav, R. P. Agarwal and S. S. Rajput
CSIR-NPL
27 ET-9 Analysis of An Accurate and Precise Two Port Waveguide Mismatch as
An Impedance Transfer Standard
Jyoti Chauhan, Naina Narang and S. K.
Dubey
CSIR-NPL
Content / List of Papers
Metrology for Advanced Manufacturing
28 MAM-1 Two Phase Flow Simulation and Experimental Validation of Semisolid
Slurry Generation Process of A380 Al alloy
Prosenjit Das, Sudip K. Samanta, Pradip
Dutta
CSIR-CMERI
29 MAM-2 Lubrication of Dry Sliding Contact by Functionalized Graphitic
Nanoparticles
Suprakash Samanta, Santosh Singh, R. R.
Sahoo
CSIR-CMERI
30 MAM-3 3D Surface Characterization of Stainless Steel Microchannel Generated by
Electrochemical Micromachining
B. Ghoshal, B. Bhattacharyya JU
31 MAM-4 Further Optimization of Superior Quality Hydrogenated Diamond-Like
Carbon Anti-Reflection Coating for Silicon Solar Cell Application
Amit Banerjee and Debajyoti Das Indian Association
for the Cultivation of
Science
32 MAM-5 Study of Size Effects, Surface Quality and Elemental Characterization of
Different Crater Geometries on Titanium Alloy in Micro Milling
Vijay, Swapan Barman, Ram Prakash
Sharma and Nagahanumaiah
CSIR-CMERI
33 MAM-6 Experimental Investigation of Chatter in High Speed Milling
by Surface Metrology
Kamalkishor J. Uke1, Ranjan Sen2, S.
B.Wadkar3 and M. C. Mujumder4
CSIR-CMERI
34 MAM-7 A Comparative Study on the 2D and 3D Surface Roughness of Direct
Metal Laser Sintered Ti6Al4V
Sumanta Mukherjee, Partha Saha, Santanu
Dhara, Ranjan Sen, Samik Dutta, Santanu
Naskar
IIT Kharagpur
35 MAM-8 Measurement analysis in Electrochemical Discharge Machining (ECDM)
Process
Pravin Pawar, Raj Ballav, Amaresh Kumar NIT Jamshedpur
36 MAM-9 Optimization of High Speed End Milling Process (HSEM) in OFHC
Copper based on Surface Roughness and Cutting Force
Sankar Karmakar, M. K. Biswal, S. Y. Pujar,
Praveen Kumar, Nitish Kumar
CSIR-CMERI
37 MAM-10 Designing a voice control Robot for its industrial use Abhishek Chaudhary and Umesh Dutta Manav Rachna
International
University Faridabad
Quality Assurance
38 QA-1 Understanding ISO/IEC 17025:2005 and Calibration & Measurement
Capabilities in Mass Measurements
Tripurari Lal CSIR-NPL
39 QA-2 Guidelines for Standardization of Lightweight Wall Design and
Installation for the Acoustical Performance in Buildings
Mahavir Singh CSIR-NPL
40 QA-3 Intermediate Checks Enhances Confidence on Calibration Intervals K. Arulselvi and K. Sankara Subramanian ETDC, Chennai
41 QA-4 Role of Inter-Laboratory Comparison in Laboratory Competence Goutam Basu ERTL(E)
42 QA-5 Best Practices for Calibration and Maintenance of Laboratory Equipment
at RDCIS, SAIL, Ranchi
K. K. Toppo, Shree Prakash, H. N. Das, R.
K. Jha, K. K. Mallik
RDCIS, SAIL,
Ranchi
43 QA-6 Quality Assurance of Gauge Block Comparison Calibration at CSIRNPL,
India for the Implementation of ISO17025:2005 Technical
Requirement 5.9
Jokhan Ram, M. Arif Sanjid, Vinod Kumar,
K. P. Chaudhary
CSIR-NPL
Content / List of Papers
44 QA-7 ISO 10012:2003(E) - Measurement Management System
Importance in Testing and Calibration Laboratories
S. K. Nag and D. Samanta Young Engineers &
Calibration Services
Pvt. Ltd., Kolkata
Uncertainty for Measurements and Standards
45 UMS-1 Establishment of Secondary Hardness Standardizing Machines at NPL
India
Rajesh Kumar and Rakesh Khanna CSIR-NPL
46 UMS-2 Comparative Estimates of Measurement Uncertainty by Two
Calibration Methods using Flame Atomic Absorption Spectroscopy
Daya Soni, Niranjan Singh, Shankar G
Aggrawal and Prabhat K Gupta
CSIR-NPL
47 UMS-3 Comparison Studies of Different Simple Shaped Precision Force
Transducers
Harish Kumar and Anil Kumar CSIR-NPL
48 UMS-4 Uncertainty Estimation in Determination of Calcium by Flame Atomic
Absorption Spectrophotometer
Khem Singh, Daya Soni, Niranjan Singh,
Nahar Singh, Shankar G. Aggarwal and
Prabhat, K. Gupta
CSIR-NPL
49 UMS-5 Need of Calibration Facilities and Preparation of Reference Materials
for Breath Alcohol Analyzers
S. Swarupa Tripathy, Nahar Singh, Rajiv K.
Saxena and Prabhat K. Gupta
CSIR-NPL
50 UMS-6 A Review on Analysis of Calibration Interval Amal K Ghosh, C. R. Datta Netaji Subhash
Engineering College
51 UMS-7 Quality System in Non- R&D Centre for Calibration & Testing at
CSIR-NPL, New Delhi
Manju Arora and V.K. Gumber CSIR-NPL
Dimensional Metrology and Machine Vision
52 DMMV-1 Development of Automated Vision Inspection System for Two Wheeler
Engine Crankshaft
R. Deepa, J.Pradyumna, S.Harsha, S.Usha CMTI
53 DMMV-2 Measurement of Surface Roughness using Non-Contact Vision based
Technique
Satwik Kulkarni, Abhinav Joshi and Dr.
Arati Mulay
CoE, Pune
54 DMMV-3 Vision Based Surgical Screw Inspection S. Harsha, R. Deepa, V. Kavitha, S. Usha CMTI
55 DMMV-4 Measurement of Diameter for Volumetric Standard Sphere with the High
Precision End Standard Gauge Blocks
Mukesh Kumar, Anil Kumar CSIR-NPL
56 DMMV-5 Development of Ultrasonic Technique for Dimensional Accuracy and
Flatness of 1.2 mm Diameter Flat Bottom Holes
Yudhisther Kumar Yadav, Reeta Gupta, P K
Dubey and Gianinder Singh
CSIR-NPL
57 DMMV-6 Ultrasonic study on Measurement of Surface Roughness of Reference
Cylindrical Blocks
Sandeep Kumar, Yudhisther Kumar Yadav
and K. P. Chaudhary
CSIR-NPL
58 DMMV-7 Remote Measurements using Image Analysis System N. J. Padte, R. V. Tambad, Dr. J. C. Padte FIE, Ichalkaranji
59 DMMV-8 Image Texture Analysis using GLCM Technique for Evaluation of
Fractographs
Samik Dutta, Himadri Roy and Ranjan Sen CSIR-CMERI
60 DMMV-9 Validation of Software used for Angle Gauge Block Calibration at CSIR-
NPL,India
M. Arif Sanjid, K. P. Chaudhary CSIR-NPL
Content / List of Papers
Pressure, Temperature, Humidity, Density (PTHD)
61 PTHD-1 A Large Diameter Piston Gauge as a Pneumatic Primary Pressure
Standard
Jasveer Singh, Ashok Kumar, Nita Dilawar
Sharma and A.K. Bandyopadhyay
CSIR-NPL
62 PTHD-2 An Over View of Humidity Standard at CSIR-NPL (India) Bhikham Singh, Gaurav Gupta, D.D.
Shivagan and Y.P. Singh
CSIR-NPL
63 PTHD-3 Calibration of Density Hydrometer by Comparison Method at CSIR-NPL M. B. Das, Anil Kumar and Surender Singh
Yadav
CSIR-NPL
64 PTHD-4 Need of Automation for Pressure Calibration in Metrology Laboratory Jnanabrata Chattopadhyay ERTL(E)
65 PTHD-5 Assessment of Pt/Au Thermocouple on ITS-90 Fixed Points
from TPW (0.010oC) to Ag (961.78oC)
Hansraj Meena, Yetendra, R. B. Sibal, D. D.
Shivagan and Y.P. Singh
CSIR-NPL
66 PTHD-6 Development of Cobalt-Carbon Eutectic Fixed Point for Contact Thermometry D. D. Shivagan, Hansraj Meena and Y.P.
Singh
CSIR-NPL
67 PTHD-7 Standardization of Capsule SPRT from T. P. of Hg to M. P. of Ga Umesh Pant, Hansraj Meena, D. D.
Shivagan and Y.P. Singh
CSIR-NPL
68 PTHD-8 Loss of Water Pressure between Upstream and Downstream Line during
Water Flowmeter Testing
I.S. Taak and Chatar Singh CSIR-NPL
69 PTHD-9 Progress towards Development of a Hydraulic Dynamic Pressure
Calibration System
A. Zafer, A. Sanjid, R. K. Sharma, L.
Kumar, V. K. Gupta and Sanjay Yadav
CSIR-NPL
70 PTHD-10 Characterization of Micropipette and Its Uncertainty Evaluation Goutam Mandal, Anil Kumar and Dinesh
Chandra Sharma
CSIR-NPL
Plenary Talk
4th National Conference on Advances in Metrology - AdMet2015 Plenary Talk
I
Metrology Matters Kamal Hossain
National Physical Laboratory, Teddington, Middlesex, UK
E-mail: [email protected]
Metrology, the science of measurement, has been an important part of our human civilisation
over many centuries. It is an essential tool for scientific research and development as well as
technological innovation. It underpins modern industrial competitiveness and supports the
development of improved and new industrial products and processes with reliable
performance and safety. Global trade and regulations depend heavily on internationally
accepted measurements and standards. At the heart of this, is the international system of
Units of Measurements (SI) and a Mutual Recognition Arrangements for accepting
measurement and traceability of results obtained in different countries.
With rapid advances in technology, ever more precise and reliable measurements are
essential to drive innovation and economic growth within our knowledge-based economy.
What we cannot measure, we do not understand properly, and cannot control, manufacture or
process reliably. Thus, advances in metrology and its effective use have a profound impact on
our understanding of and ability to shape the world around us.
Thus measurements play an important part in all aspects of our daily life and our well-
being. In fact metrology has a vital role in meeting grand challenges facing our society to-day
such as environment, energy and health.
The talk will cover:
• What is metrology, and its importance and impact in daily life;
• The International System of Measurement Units (SI) and how it operates in a global
framework;
• How measurements contribute to industrial innovation and competitiveness;
• Role of measurements in medical diagnostics and treatment for human health;
• Advances in metrology and future trends.
Invited Talk
4th National Conference on Advances in Metrology - AdMet2015 IT-I
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Towards Redefining Temperature using Sound Velocity Measurements
Prof. E. S. Raja Gopal Emeritus Professor, Department of Physics,
Indian Institute of Science, Bangalore 560 012
E-mail: [email protected]
Currently temperature is defined using the triple point of water as 273.16 K. This is based on
the artifact, namely water, and is also accurate to 10 parts in a million only. By comparison
length, frequency and some electrical standards are defined to about 10 parts in a billion, a
thousand times more accurately known. This has become possible because of going to atomic
quantum measurements.
About 50 years ago the task of linking temperature with the fundamental atomic constants
began and 25 years ago, with the technological advances, the first experiment was performed
in the National Bureau of Standards, USA (now NIST). It involved the measurement of
sound velocity in a monoatomic gas at low pressures, extrapolated to zero pressure to realize
the ideal gas. The square of the velocity is (gamma)RT/M, where R is the gas constant and
M the molecular mass of the gas. For a monatomic gas (gamma) is exactly 5/3. The gas
constant could be estimated to an accuracy of 1 part in a million. By early 2000 the
Avogadro number N could be determined to a level of 0.1 part in a million, using what is
commonly called the atom counting technique. Further improvements in the sound velocity
measurements and a better theory of the boundary layer correction in 2012 has now enabled
R, N and the Boltzmann constant k to be measured to an accuracy of 0.3 parts in a million.
Thus a serious discussion of redefining the temperature in terms of the fundamental constants
has begun. The issues in preparing a new definition will also be discussed.
4th National Conference on Advances in Metrology - AdMet2015 IT-II
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Invited Talk
Anil Relia Director, NABL, New Delhi
E-mail: [email protected]
4th National Conference on Advances in Metrology - AdMet2015 IT-III
IV
Metrology in Modern Day Medical Practice
Dr. Rajat Mukherjee SRL Laboratories
E-mail: [email protected]
Measurements have been an integral aspect of Human civilisation and has been an
inseparable aspect of all human activities. Human history both Biblical as well as ancient
Indian is replete with references to measurement systems. Metrology or the science of
measurements has come a long way since those days when measurement was based on
human body parts to current day yotto at 1024 to yocto at 10-24 units. Measurements have
come under regulatory requirements with the advancement of civilisation.
Measurements play a crucial role in Medical sciences both for diagnosis and treatment
of human illness and covers all aspect of interactions from the time a baby is conceived
through its entire phase of growth through adulthood to senescence and demise.
Measurements in Medical sciences is applicable from the simple tongue depressor to
complex multifunctional equipment like Heart lung machine, PET CT scan, linear
accelerator and the myriad of simple to complex direct measurement equipment used in
Clinical laboratories like modern auto analysers, cell counters, FACS, Real time PCR, etc.
All human measurement parameters are defined by science and are applicable
globally although within a range. Though these ranges are wide in comparison to physical
sciences which allows a larger range of measurement uncertainties, the need for accuracy and
precision cannot be overemphasised because errors can very easily result in loss of life or
limb. Medical decisions are based on measurements present and past which requires that all
these measurements have metrological traceability and harmonisation of systems and it can
be achieved by effective quality assurance and accreditations. Quality assurance in Clinical
laboratories has seen remarkable progress in India in the last two to three decades with the
giant steps being taken by NABL and NABH.
The need for regulatory requirements in medical metrology has been appreciated and
has made steady progress over the years. Each country or economic groups have their own
regulatory requirements but a global uniformity on this is yet to take shape.
4th National Conference on Advances in Metrology - AdMet2015 IT-IV
V
Technique of Estimations and Expressions of Calibration and Measurement Capability (CMC) –Advantage to all Calibration
Laboratories
A. Dasgupta Former scientist - CMTI & Former Tech Director -HFPL
Email: [email protected] Abstract: The best measurement capability (BMC) has been changed to CMC (Calibration & measurement capability). These changes in nomenclature have adopted by all calibration laboratory, many a times without clear understanding of the advantage given by ILAC as well NABL. In the present concept of CMC, there are certain guidelines provided by both these organization in terms of estimation & expression of CMC, which helps the calibration lab as well as user testing lab & inspection wing of Quality Assurance department in manufacturing scenario. Abbreviations: CMC-calibration & measurement capability. BMC- Best measurement capability, AB- Accreditation Body, DUC- Device under calibration, ILAC- International Laboratory Accreditation Cooperation, NABL-National Accreditation Board for Testing and Calibration Laboratories, India. 1. Introduction:
The best measurement capability (BMC) has been changed to CMC (Calibration & measurement capability). These changes in nomenclature have adopted by all calibration laboratory, many a times without clear understanding of the advantage given by ILAC as well NABL. In the new concept of CMC, there are certain guidelines provided by both these organization in terms of estimation & expression of CMC, which helps the calibration lab as well as user testing lab & inspection wing of Quality Assurance department in manufacturing scenario. The capability of a calibration laboratory is assigned by an Accreditation Body. This is done by the estimation of Measurement uncertainty during demonstration in actual assessment. It was presumed that laboratory will have a Nearly Ideal device as Device under calibration (DUC) in order to get best possible estimate of MU. But in reality, majority of the lab, far from Nearly Ideal Device, could not even organize to demonstrate with a DUC which has no imperfections. As an eventuality, though several laboratories had intrinsic higher capability (i.e. lower uncertainty contribution), their inability to produce a better DUC, used to get a crude value of BMC. This aspect was a world wide phenomenon and was raised on different platform to arrive at a better solution. As a consequence ILAC came out with a doc- ILAC Policy for Uncertainty in Calibration. ILAC-P14:12/2010. Subsequently NABL doc143 was published in 2012. 2. Concept of CMC
21. CMC is a calibration and measurement capability available to customers under normal conditions:
2.2. Under a CMC, the measurement or calibration should be: performed according to a documented procedure
and have an established uncertainty budget under
the management system of the NMI or the accredited laboratory;
performed on a regular basis (including on demand or scheduled for convenience at specific times in the year);
Available to all customers. 2.3. During the demonstration for the assessment by any AB, the lab is expected to use best existing device as DUC. The term “best existing device” is understood as a device to be calibrated that is commercially or otherwise available for customers, even if it has a special performance (stability) or has a long history of calibration. This is the improvement over earlier concept of “Nearly ideal device” in connection with BMC. 2.4 CMC describes the realisable measurement capability of a laboratory and includes the attributes of a relatively ideal artefact being calibrated. 2.5 A reasonable amount of contribution to uncertainty from repeatability shall be included and contributions due to reproducibility should be included in the CMC uncertainty component, when available. Reasonable amount of contribution to uncertainty from repeatability generally means the repeatability in a short span of time. If any part of the repeatability is not to be taken, it should be supported by Technical justification. Reasonable amount of contribution to uncertainty from reproducibility is to be taken where necessary and asked by the Standard method. 2.6 The resolution of Device to be considered when reading the variations in observations on DUC. - In cases where variations are read on reference standard; the resolution of reference standard to be considered. -Alternatively, ±10% of resolution of DUC at set value as parallax error may be considered. 2.7 Standard uncertainty due to the reference standard used in the respective calibration. These may include:
4th National Conference on Advances in Metrology - AdMet2015 IT-IV
VI
- Standard uncertainty of the calibration (based on the uncertainty reported in the calibration certificate) -Drift of the reference standard (based on the historical data) - Working condition of the reference standard (based on variation in temp etc.) 2.8 Bias (when the nature of the bias is such that it can not be minimized through correction, adjustment or repair). (E.g. the deviation from nominal of a gage block length as reported on its calibration certificate) 2.9 These guidelines are amply clear that some of the factors which are considered to be included in assigning the uncertainty of DUC, need not be considered for CMC calculations- -Wherever possible and identifiable, Imperfection of best existing devices like hysteresis, relative accuracy etc. are not to be taken directly -It is recognized that for some calibrations a “best existing device” does not exist and/or contributions to the uncertainty attributed to the device significantly affect the uncertainty. If such contributions to uncertainty from the device can be separated from other contributions, then the contributions from the device may be excluded for arriving at CMC figure. As a matter of fact, these factors in most of the cases will substantially lower the value (CMC) from MU of DUC, excepting where k value will increase due to low deg of freedom.
3. Expression of CMC & MU
The CMC as well as MU of DUC can be expressed in following ways-
1) A single value, 2) A range, 3) An explicit function, 4) A matrix, 5) A graph. a) A single value, which is valid throughout the measurement range / part of the measurement range. When single value of CMC, following points to be kept in mind -The numerical value of the expanded uncertainty shall be given to, at most, two significant figures -The numerical value of the measurement result shall in the final statement be rounded to the least significant figure in the value of the expanded uncertainty assigned to the measurement result b) A range. In this case the calibration laboratory should have proper assumption for the interpolation to find the uncertainty at intermediate values. The ranges shall be split on the basis of capability of the reference standard(s)/master(s) used and different methods/procedures adopted by the laboratory. It is preferably advisable to split ranges to ensure linear relationship between CMC ranges and measurement ranges of the parameter. Wherever linearity is not feasible in a range, it is recommended that the other form of regression equation (i.e. polynomial, exponential) can be used. However in all the cases, a
more conservative fit should be applied by correcting the best fit equation. c) An explicit function of the measurand or a parameter. d) A matrix where the values of the uncertainty depend on the values of the measurand and additional parameters. e) A graphical form provided there is sufficient resolution on each axis to obtain at least two significant figures for the uncertainty.
References
[1] National Voluntary Laboratory Accreditation Program- Lab Bulletin - Issue Date: January 20, 2012 .NUMBER: LB-65-2012. LAP: Calibration
[2] Danak Accreditation Regulation Uncertainty of measurement in calibration No. : AB 11 Date: 2011.12.01 Danish
[3] KAN-G-01 KAN Guide on the Evaluation and Expression of Uncertainty in Measurement. Issue Number: 3. January 2011. Komite Akreditasi Nasional. National Accreditation Body of Indonesia
[4] "Best Measurement Capability" is Ousted; "Calibration & Measurement Capability" is Favored. FAQ Prepared for Accredited Labs by UKAS
[5] The American Association for Laboratory Accreditation. R218
[6] DAC-REQ-11 Issue 1, Rev. 0 November 2010. Dubai Accreditation Department– Dubai Municipality.
[7] HOKLAS Supplementary criteria no 13 . Implementation date 1st Nov 2010.
[8] ILAC Policy for Uncertainty in Calibration. ILAC-P14:12/2010.
[9] Policy on Calibration and Measurement Capability (CMC) and Uncertainty in Calibration. Doc No 143. NABL
4th National Conference on Advances in Metrology - AdMet2015 IT-V
VII
Nano Dimensional Metrology-New Challenges
Dr. K. P. Chaudhary
CSIR-National Physical Laboratory, New Delhi
E-mail: [email protected]
Dimensional Metrology is very important activity when it comes to industrial Metrology.
Manufacturing industries especially automobile sector cannot flourish without dimensional
measurements. Nano dimensional metrology is a challenging aspect of this field. It is also of
crucial nature as at nanometre level special attention in term of high accuracy and
sophisticated instruments are required.
A lot of research is happening in the field of nano dimensional metrology across the
globe. It can be divided into different parts for example core surface topography metrology,
metrological AFM, X-ray computed tomography, Optical methods for nanostructure
metrology etc.
In this presentation, we will discuss about the need of nano dimensional metrology
and ongoing research across the globe. We will also discuss the current status at NPL India.
We will also highlight on some areas like surface topography, Atomic Force Microscopy, X
ray computed topography etc.
In the last, future challenges in nano dimensional metrology are also discussed.
4th National Conference on Advances in Metrology - AdMet2015 IT-VI
VIII
Nanometrology: Needs and Challenges
V. N. Ojha CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi-110012
Email: [email protected]
Nanoscience, Nanotechnology and Nanometrology areas have open up a new chapter in the
field of science due to its vast importance in today’s world. In this paper we will discuss
about the need of nanometrology (the science of measurement at nanoscale) and about the
challenges and opportunities therein. Furthermore, we will discuss about the standards and
standardization and their roles in nanometrology.
In view of the demand of nanoscience and nanotechnology measurements in the
country NPL-I (also the National Measurement Institute of India) has taken up the task of
establishing the traceability infrastructure for the few of the parameters in the field of
nanometrology. In this talk we will highlight about the status of these parameters at NPL-I.
4th National Conference on Advances in Metrology - AdMet2015 IT-VII
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Advances in Temperature Standards and Precision Metrology
Y.P. Singh CSIR - National Physical Laboratory,
Dr. K.S. Krishnan Marg, New Delhi-110 012, India.
E-mail: [email protected]
This paper presents the review of the current aspects of temperature standards and precision
metrology with the historical developments made in the area of thermodynamic temperature
and related temperature scales. The formulation and importance of international temperature
scale and its revision from time to time due to increase in the accuracy, development of new
technologies, availability of materials, easier methods of realization of temperature fixed
points (equilibrium states) and enhancement of temperature ranges according to the need with
the time are presented. The unit of temperature, kelvin at present is defined as a fraction
1/273.16 of the thermodynamic temperature of the triple point of water and thus its
dependence on the material’s property. It is required to be redefined in terms of the
fundamental laws of physics. Since temperature is always associated with the coefficient of
thermal energy, kBT, where, kB is the Boltzmann constant, it becomes easy to define it in
terms of this fundamental constant.
The future definition of temperature unit Kelvin is expected to be as following -“The
unit of thermodynamic temperature, kelvin, K is the change of thermodynamic temperature
that results in a change of thermal energy kB.T by 1.38065XXX x10-23 Joule”. In this way
the unit of temperature will become independent of material’s property. The set-up of primary
standards as defined at present and to be redefined in future are depicted in the following
figures.
Under the 12th Five Year Plan at CSIR-NPL, we have taken a new project under
which, work has been started to establish experimental facility for acoustic gas thermometry
to determine Boltzmann constant for re-defining the unit of temperature in terms of this
constant kB. This is one of the new developments in the modern thermometry leading to the
highest degree of accuracy (low uncertainty) of temperature and its independency with the
material’s property. A significant work has already been done in the various National
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Metrology Institutes over the world like NPL, UK, PTB Germany, NIST USA NMIJ Japan
and KRISS Korea.
Fig.1 Fig.2
Fig.1: Triple Point of Water. Fig.2: Acoustic Gas Thermometry
Keywords: Thermodynamic temperature, ITS-90, triple point of water, thermal energy,
acoustic gas thermometry, Boltzmann constant, uncertainty.
4th National Conference on Advances in Metrology - AdMet2015 IT-VIII
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A Novel Approach towards the Determination of E-Mass by Differential
Pressure Measurement
A.K. Bandyopadhyay Chief Scientist (Retd), Editor in Chief, MAPAN- JMSI, Ex. Chairman, Technical Committee for Mass related
Quantities, APMP(2005-2009), Ex. Executive Committee Member, APMP (2009-2013) and Ex. Head, Apex
Level Standards and Industrial Metrology, National Physical laboratory, New Delhi – 110012, India’
E-mail: [email protected]
A watt balance is relatively simple in principle but the real challenge is to perform the experiment
with a relative uncertainty in measurement of 1x 10-8.The hardest parts of the experiment are: (a)
moving the coil in a strictly vertical line, (2) aligning the coil axis with gravity and the magnetic field
at right angles to gravity. Existing Watt Balance experiments require correction systems, which add
complexity and potentially introduce ‘noise’ to the system. MSL (New Zealand) [1] has developed a
novel approach to overcoming these design problems.
Figure 1: Twin Pressure balance with the measuring system [courtesy MSL New Zealand]
A twine pressure balances is used as a mass comparator [shown in Fig. 1]. As the differential pressure
(Δp) is directly related to differential mass (Δm). The force generated by this Δm can be compensated
by the utilization of an electromagnetic force which is generated by a moving coil in a magnetic field.
In other words, as the coil is immersed in a horizontal magnetic flux, the current I in the coil exerts a
vertical force on the conductor that is balanced against the weight (Δm). There will be an equilibrium
condition, that is, the force generated by the differential pressure (say upward) and electromagnetic
force (say downward) and vice versa. Under this condition, the fall of the piston is sinusoidal with
reference to the equilibrium condition. Figure 2 shows a typical balancing situation where the upward
force is balanced by the downward force. The amplitude of the oscillation decreases as the downward
4th National Conference on Advances in Metrology - AdMet2015 IT-VIII
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force is trimmed by increasing the coil current under a constant magnetic field maintaining the same
mass at the other side of the differential pressure balance.
Figure 2: The oscillation of the pressure balance during the equilibrium condition is shown against the time
If the piston fall is measured by a laser interferometer and electromagnetic force by measuring the
current and voltage as are done in the conventional Watt Balance technique that is, the calibration and
measurement modes of operation, the same principle can be used. Under this condition, the coil is
moved at a constant velocity v in the vertical direction through the flux and the voltage U induced
across the coil and also in the calibration mode if the current I under the magnetic field B moves the
coil velocity v: Δm = UI/gv. It is to be mentioned here that the fall rate of the piston is oscillatory in
nature. If we have a laser measuring system which can track the oscillatory motion of the coil with
very high accuracy, we will get rid of the shortcoming of conventional Watt Balance where fall is at a
constant speed. Pressure balances meet the key Watt balance requirements (a) means of moving coil
straight and vertical as it is directly connected with a piston which moves in a well-defined axis and as
a result the movement of the coil is almost vertical, (b) Floating element moves vertically within 1 μm
over 10 mm(c) it is a weighing device of sensitivity with 1 part in 108, (d) very low friction because of
very narrow clearance less than 1 µm; (e) aerodynamic bearing with strong piston centering forces;
finally, (f) no contact between piston-cylinder.
Acknowledgement : The author thanks Dr. Sutton for providing documents from time to time.
[1] Chris M Sutton, Measurement Standards Laboratory of New Zealand “MSL watt balance research:
Status report to CCM Workshop on the mise en pratique of the new definition of the kilogram” 21&
22 November 2012, BIPM, Sèvres, France.
4th National Conference on Advances in Metrology - AdMet2015 IT-IX
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Friction Stir Welding: Application and Development
Surjya K. Pal, Kanchan Kumari
Department of Mechanical Engineering
IIT Kharagpur, 721 302
E-mail: [email protected]
Friction Stir Welding (FSW) is considered to be one of the most significant processes in
metal joining area. This technique was developed and expanded by The Welding institute
(TWI) in the year of 1991 [1]. The most inherent part of the FSW technique is the non-
consumable tool which comprises of two parts. One is the shoulder part and the other one is
the pin part. Both the tool and shoulder dimensions are very much crucial and hence choice
of these two parameters are challenging like other parameters such as rotational speed,
welding speed, tool tilt angle and plunge depth. Therefore, a large number of researchers are
focusing on tool geometry, design and development of the tooling systems in FSW.
This green technology has a lot of advantages, such as no toxic gas or fume is generated
during welding; no need of any external consumables; environment friendly; also less
consumption of energy. The fundamental and major difference between conventional and
FSW is the evolution of heat. In this new technology, unlike the conventional method there is
no addition of heat from any outside source. Both by friction between the tool and work
piece, and plastic deformation of the mating surfaces due to the rotation of the tool generate
heat which is sufficient to join the two surfaces.
Broad areas of applications have been captured by this new technology, such as
manufacturing, automobiles, aviation and many more. Mitsui Engineering and Ship Building
uses FSW process for the prefabrication of the aluminum panel of superliner Ogasawara.
NASA applies FSW process for manufacturing of space shuttle external tank. Many robotics
companies like KUKA robot group adapted this new technology for fabrication purpose. This
new technique has also been adopted in the field of computer world such as joining of the
bottom back part of the Apple iMac [2].
There are developments of the tooling system of FSW. Some of the typical tool
systems developed by TWI are whorl, MX Triflute, Flared Triflute, Re- stir, Skew-stir tools
4th National Conference on Advances in Metrology - AdMet2015 IT-IX
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etc. Since conventional FSW requires excessive clamping force both in upper and lateral
directions, one such new variant technique termed as Twin Stir technique has been developed
and invented by TWI [3]. In this process, two tools counter each other, carryout the welding,
where the second tool overlaps the first one. The main advantage of this technique is that the
torque generated by first tool is counteracted by the second one, which helps in requiring less
clamping, and also higher welding speed can be also be used. These paired tools also
generate heat through the thickness and also produce symmetrical weld. In addition, this
tandem twin stir technique also improves the weld integrity, where due to the second pass
over the previous tool the oxide layer remaining in the first pass is fragmented and disrupted
at the cost of no loss of mechanical property. Hence the secondary need not to be as robust as
the previous tool. Since there is no published research on this twin tool system, efforts are
made recently at IIT Kharagpur to design, fabricate and carry out experiment by using the
twin-tool system. This new setup has been used to weld Al alloys [4]. Further developments
on the twin-tool system have already been taken place, and a recently patent filing has been
done in this regard.
1. W. M. Thomas, E. D. Nicholas, J. C. Needham, M. G. Murch, P. Templesmith, C. J.
Dawes, (1991) “Friction stir butt welding”, International Patent Application No.
PCT/GB92/02203, GB Patent Application 9125978.8, UK Patent Office, London.
2. W. M. Thomas, S. W. Kallee, D. G. Staines, P. J. Oakley, (2006) “ Friction stir welding-
Process variable and developments in automotive industry” , SAE World Congress, Cobo
Center, Detroit, Michigan, USA.
3. W.M. Thomas, D.J. Staines, E.R. Watts, I.M. Norris, (2005) “The simultaneous use of
two or more friction stir welding tools”, TWI Ltd. report, Cambridge, U.K.
4. K. Kumari, S. K. Pal, S. B. Singh, (2015), “Friction stir welding by using counter-rotating
twin tool”, Journal of Material Processing Technology, vol. 215, pp. 132-141.
4th National Conference on Advances in Metrology - AdMet2015 IT-X
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Calibration Interval for Weight Calibration
Anil Kumar*, Goutam Mandal and Dinesh Chandra Sharma CSIR – National Physical Laboratory, New Delhi, India
* E-mail: [email protected]
It is frequently asked question, what should be the next calibration interval for weights? No clear guidelines are
available in written international standards of weights (OIML R 111, ASTM E617 etc.). On the other hand, the
ISO/IEC 17025 : 2005 standard, which is the basic document for calibration and testing laboratories, says no
date for next calibration interval should be given. It should be decided by the customers on its use and
maintenance.
Calibration interval of weights can be decided on the following factors :
a) Measured mass value and allowable tolerance limit;
b) Level of stress to which the weights subjected;
c) Stability of past calibration(s);
d) Quality assurance requirement.
In Authors’ opinion the weight calibration interval should be decided on two factors and partially
environmental conditions of measurement. The two factors are
i) Material from which weights are made;
ii) Storage and handling of weights.
Fig.1 : Control chart of NPK-57
Weights are made of different materials like stainless steel, brass, cast iron, aluminum, nickel-chromium
alloy etc. It is clear that what is the calibration interval of stainless steel weights should not be same for made of
aluminum or brass. Later materials are softer material.
National prototype kilogram copy No. 57 (NPK-57) is made of platinum-iridium alloy. As per BIPM’s
decision, calibration interval of NPK-57 is not more than 10 years. From first calibration in 1957 to last
calibration in 2012, NPK-57 has lost 51 µg in compared to International Prototype Kilogram (see Fig.1).
-0.054
-0.022
-0.036
-0.044
-0.051
-0.070
-0.060
-0.050
-0.040
-0.030
-0.020
-0.010
0.000
1955 1985 1992 2002 2012
Dev
iatio
n fr
om n
omin
al v
alue
(mg)
Year
4th National Conference on Advances in Metrology - AdMet2015 IT-X
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Fig. 2 : Control chart of Transfer Standard made of
Stainless Steel
Fig. 3 : Control chart of Transfer Standard made of
Nickel-chromium alloy
Fig. 2 shows the value of weight made of stainless steel which is normally calibration interval obey 3
years. Fig.3 shows the behavior of weight made of nickel-chromium alloy. Here deviation is more, this also has
calibration interval of 3 years. From these graphs show that the calibration interval is depended on material from
which they are made.
Determining the calibration interval of weight requires complete knowledge of examination of the weight
every time and the process for using the weight. We should know how the weight is handled and stored.
Changes in the mass value could be associated with excessive wear or abuse of the weight. This can be judged
by the surface of weight and partially how the weight are kept in proper environmental conditions and protected
from air borne contaminates.
The required uncertainty of measurement should be assessed. If the weight’s reproducibility is shown by
successive calibrations to be substantially better than the uncertainty required than the interval between
calibrations can be extended by three years.
-3.110
-3.210-3.212
-3.199
-3.248
-3.155
-3.268
-3.320
-3.360
-3.310
-3.260
-3.210
-3.160
-3.110
-3.060
-3.010
1957 1981 1988 1999 2001 2003 2008 2011
Dev
iatio
n fr
om n
omin
al v
alue
(mg)
Year
-1.470
-1.537
-1.678
-1.597
-1.857
-1.867
-2.000
-1.900
-1.800
-1.700
-1.600
-1.500
-1.400
1988 1999 2001 2003 2007 2011
Dev
iatio
n fr
om n
omin
al v
alue
(mg)
Year
4th National Conference on Advances in Metrology - AdMet2015 IT-XI
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National Pressure Standards: Overview and Report on New Developments
Sanjay Yadav National Physical Laboratory (NPL),
Council of Scientific and Industrial Research (CSIR),
New Delhi – 110 012, INDIA
E-mail: [email protected]
The national pressure standards established at NPL are mostly dead weight piston gauges.
Piston gauge is a device that realizes pressure directly from the fundamental definition of the
pressure and is often used as a primary / secondary pressure standard. Its main components
are a piston-cylinder assembly and a weight. In order to keep pace with advancement in the
field and cater the ever increasing demands of the industry and users for better and improved
traceable pressure standards, NPL is also continuously focusing on to develop, establish and
upgrade its pressure measurement capabilities. Recently, NPL has established and
characterized controlled clearance piston gauge (CCPG) type primary hydraulic pressure
standards in the pressure ranges of 10 to 100 MPa and 20 – 200 MPa. The recent efforts are
being made to develop semi-automatic CCPG in the low pressure ranges 1 MPa to 10 MPa; 5
MPa to 50 MPa and in high pressure range from 50 MPa to 500 MPa. These CCPGs are the
unique systems being established at NPL having expected measurement uncertainties
associated with effective area (A0) better than 60 ×10-6 at a coverage factor, k = 2. We are also
working on the development of new facilities for the differential hydraulic pressure
measurements up to 50 MPa, first time in India. The present paper describes the overview of
the piston gauge type hydraulic pressure standards established at NPL over the years, their
measurement traceability, existing calibration services, the CMCs registered in the Appendix
‘C’ of BIPM, recent results of the key comparisons and the progress towards new
developments being carried out.
PS-I Health Care (HC)
4th National Conference on Advances in Metrology - AdMet2015 HC-1
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Quantitation in Routine Microbiology Testing
Dr. Bhaskar Narayan Chaudhuri MD (Cal), Consultant Microbiologist & Infection Control Officer,
Fortis Hospitals, Anandapur, Kolkata
Many Microbiology, Serology and Molecular Biology tests need quantitative analysis and
interpretation. The present discussion is focused on routine microbiological tests. On Gram
stained smears of respiratory samples, pus cells > 25/ LPF and epithelial cells < 10/ LPF
signify properly collected specimen. Significant pyuria is presence of > 1 pus cell/ 7 HPF in
non-centrifuged urine, or > 5 pus cells/ HPF in centrifuged urine deposit. Acid fast bacilli
seen on Z. N. stained smears are graded from ‘scanty’ to ‘3+’ as per RNTCP guidelines. All
important equipment in the Microbiology section need regular calibration. Colony counts,
which give an idea of microbial load in the parent sample, should be reported for urine,
respiratory samples, vascular line tips, water and air cultures – either by using sophisticated
colony counters or, more commonly, by estimation from standard methods. For water
samples, membrane filter technique or plates with grids are used. For air samples, settle
plates or air samplers with agar strips are used. Colonies are counted and total number of
colony-forming units (cfu) per cubic metre of air is obtained by using a formula. Standard
plating techniques of liquid or semi-liquid samples on agar plates with 0.01 ml
bacteriological loops follow the principle of diluting the sample streaked approximately 10
times on subsequent streaks. A semi-quantitative estimate of colonies can be given once
growth occurs. For urine samples, 0.001 ml loops are used. Cfu/ ml of urine are obtained by
multiplying number of colonies grown by 1000. Loops can be calibrated in-house by a
standard loop calibration method. Significant bacteriuria is generally the presence of > 105
cfu/ ml of urine. On cultures of respiratory samples, significant colony counts are > 105
cfu/ml for sputum and tracheal aspirates; > 104 cfu/ml for BAL; and > 103 cfu/brush for PSB.
For vascular line tips, colony count of > 15 is significant. Distinction between true infection
and colonization is possible by examination of direct smears of samples and colony counts.
For blood and body fluid cultures, time to positivity in automated systems is directly
proportional to the microbial load in the parent sample, and indicates the likely source of
infection in case of multiple samples sent from different sites. Antimicrobial susceptibility
tests are mostly performed by Kirby-Bauer disc diffusion method. Zone diameters are
4th National Conference on Advances in Metrology - AdMet2015 HC-1
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measured for reporting the isolates as Sensitive, Intermediate or Resistant, following standard
guidelines (CLSI, EUCAST or BSAC). It is desirable to report MIC values of antimicrobials.
Some gadgets extrapolate MICs of the antibiotics from their zone diameters, since a
regression line correlation exists between the two. Exact MICs can be detected with E-test
strips or dilution methods. Breakpoint MICs are detected by automated systems like
Microscan and Vitek2C. Inoculum preparation from pure colonies and adjusting it to
requisite McFarland value using densitometer is vital for the testing. Standard ATCC Control
strains should be maintained by the laboratory for internal quality control of microbiological
testing.
4th National Conference on Advances in Metrology - AdMet2015 HC-2
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Point-of-Care – Coagulation Testing: An Insight
Dr Sugat Sanyal, Dr Rajat Mukherjee
Department of Lab Services, Peerless Hospital, Kolkata
Monitoring and control of anticoagulation therapy at bedside has been plagued with a
relatively high incidence of adverse reactions, either hemorrhage or thrombosis. This has
been due to the complexity of anticoagulation therapy and the narrow therapeutic window of
anticoagulation drugs such as heparin or warfarin. A number of innovations have emerged in
response to these problems. In some clinical settings, the desire for immediate results of
coagulation testing has been met with the placement of coagulation analyzers at the point of
care (POC). Several technologies are used in point-of-care monitoring of anticoagulation in
cardiac surgery units, intensive-care units, and dialysis units. Activated coagulation time/
Activated clotting time (ACT) is measured mostly in these settings. ACT is measured with a
specially designed coagulometer, using whole blood specimens. Quality control and quality
assurance of point-of-care testing are particularly important because of the danger of adverse
reaction to anticoagulation therapy. However in most institutions this aspect is paid scant
attention due to cost and poor training in quality assurances. This review highlights the
principles used and the need for bringing POCT in coagulation testing under the QA
procedures of Lab Services to improve patient safety.
4th National Conference on Advances in Metrology - AdMet2015 HC-3
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Burden of Particulate Matters in Punjab due to Agriculture Crop Residue
Burning Seasons Affecting Health of School Children
Sachin Gupta, Ravinder Agarwal and Susheel Mittal
Thapar University, Patiala
E-Mail: [email protected]
A cross sectional study has been carried out to observe the effect of Suspended Particulate
Matters (SPM) in the ambient air on the respiration parameters of children in urban areas of
Punjab. Study mainly covers the Agriculture Crop Residue Burning (ACRB) season for rice
and wheat crop residue burning period and their impact in urban areas. A ground level study
was done in Amritsar, Ludhiana and Gobindgarh of Punjab to measure the concentration of
Inhalable particulate matters (PM20, PM10, PM5) and respirable particulate matters (PM0.23,
PM0.50, PM1.0). To measure the respiration parameters, 50 healthy subjects (students) with
age group 8 to 16 years were selected from schools in respective cities. American Thoracic
Society (ATS) standards were used during the selection of subjects. For respiration
parameters, pulmonary function test was performed on subjects and various parameters like
Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Peak
Expiratory Flow(PEF) and Forced Expiratory Flow in 25 to 75% (FEF25-75%) were
measured. The results indicate that as compare to non-burning seasons, level of SPM was
more in peak burning seasons and corresponding to that respiration parameters varies.
Negative correlation was estimated between respiration parameters and level of inhalable
particulate matters and respirable particulate matters. Maximum negative correlation was
found for respirable particulate matters as compare to inhalable particulate matters. Using
linear regression method, variation in respiration parameters has been calculated (CI: 95%).
Maximum percentage variation is seen in Gobindgarh. After crop residue burning seasons, it
has been observed that both inhalable and respirable particulate matters produce an
unrecoverable effect on the respiration parameters of children.
Keywords: SPM, Respiration Parameters, Correlation Coefficient, Variation in parameters.
4th National Conference on Advances in Metrology - AdMet2015 HC-4
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Metrology for Safety, Environment and Public Health
Col. (Retd.) Prabhdeep Singh Sandhu1 and Govind Swaroop Pathak2 1National Institute of Technology, Durgapur
2Indian School of Mines Dhanbad
E-mail: [email protected]
Metrology is an applied field of science related to measurements with its application on wide
range of fields. There is no doubt in saying it is the science with the maximum impact on the
society. Metrology applies to Aerospace, commercial nuclear power, medicine, medical
devices, chemicals and so on. By default, the metrologists become responsible for the
providing sufficiently correct measurements. Correct measurements are essential to
commerce and any defects in metrology will have a greater impact on the society especially
in the areas of healthcare and public safety. Legal metrology in health and safety applications
can significantly provides early warning signals, reduce accidents by changing people’s
behaviour and providing effective enforcement of safety requirements. Instruments with high
precision are required for measuring organic and metal pollutants, pesticides, toxic
substances and automobile emissions and any discrepancies in these may deteriorate not only
the environment in addition to having a significant effect on the lives of innumerable
organisms from the microbiota to the Homo sapiens. Biomedical technology is improving in
rapid speed and several advanced diagnosis tools are coming up every day. These
technologies will be safe for the humanity and other living beings and will not have any
social benefits unless they are precise. Herein, we report the present scenario, shortcomings
and the road map for metrology for safety, environment and public health in India through a
few case studies. The article will throw light on the role of corporate social responsibility as a
tool for improving legal metrology for health care in India.
Keywords: Legal Metrology, Health Care, biomedical devices, Corporate Social
Responsibility
4th National Conference on Advances in Metrology - AdMet2015 HC-5
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Guidelines for Measurement of Mass in Pharmaceutical Laboratories
Tripurari Lal Ex. Scientist G & Head, Mass Standards
National Physical Laboratory New Delhi (India)
E-mail: [email protected]
The measurement of mass, have always been affecting every activities of our everyday life as
well as a broad range of manufacturing industries, including Medical/Chemical &
pharmaceutical Testing & Calibration Laboratories. Based on various national and
international available practices, this document is intended as a guide to the best practices to
be adopted when carrying out weighing in these Testing & Calibration laboratories. For the
Medical/ Chemical/ Pathological/ pharmaceutical activities, the only one common term
‘Pharmaceutical’ is used in this paper. This Guide also establishes metrological requirements
for the calibration of measuring devices (weights & balances) used to determine the mass
within the scope of reference measurement procedures in such measurement laboratories.
This Guide also specifies the method for determination of the relative expanded uncertainty
of the estimated mass of any product weighed.
4th National Conference on Advances in Metrology - AdMet2015 HC-6
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Measurement and Analysis of Key Anatomical Parameters in Cervical
Spine Area of a Representative Sample of Indian Population by using
Computerized Tomography
Partha Sarathi Banerjee Sr. Principal Scientist, CMERI, Durgapur
E-mail: [email protected]
The purpose of the present study has been to measure the surgically important morphological
parameters of Cervical Spine region of a representative sample of Indian population from the
images obtained through Computerized Tomography (CT). Another purpose has been to
compare the computed statistical mean, standard deviation and range of variation of these
data with those of other Asian population and also European/American population. With that
aim, one hundred (100) CT scan data of Indian people (75 for male patients and 25 for female
patients) pertaining to undeformed normal Cervical Spine have been collected from an Indian
hospital. From these CT images, 15 important morphological parameters have been
measured. These values have been tabulated and their mean, standard deviation and range of
variation have been computed. It has been found that Pedicle dimensions of Indian people
are smaller at almost all vertebra levels as compared to Caucasian people. Pedicle Axis
Length for Indian people are found to be smaller at C3, C4 and C5 levels than those for other
Asian people including Chinese people, but it is bigger at C6 and C7 levels. Indian people
have longer measurements of Pedicle Length + Lateral Mass on an average than their other
Asian counterparts at C5, C6 and C7 levels, but shorter measurements at C3 and C4 levels.
The results of the present work may help in better understanding of morphological
parameters of Cervical Spine region of Indian population. It may be further useful in
designing spinal implants which would be biomechanically compatible to the anatomy of
Indian people.
Keywords: Anatomy, Cervical Spine, Indian Population, Morphological Data, Pedicle,
Vertebra
4th National Conference on Advances in Metrology - AdMet2015 HC-7
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Measurement Technique of Osteological Parameters of Femur
Palash Kumar Maji, S. K. Mandal, A. K. Prasad and S. Karmakar
Scientist, CSIR-CMERI, Durgapur
E-mail: [email protected]
There are significant differences in skeletal structures amongst the population of different
geographical location and ethnic groups. The effect is more pronounced in the hip joint,
considered to be one of the important load bearing joints. The morphology of proximal femur
is an essential parameter in the design and development of implant for THR. Literature
review clarify that one of the reasons of aseptic loosening of femoral stem is the improper
shape and size of stem with respect to the morphology of proximal femur of a particular
population. To design suitable femoral prosthesis for a group of Indian population, One
Hundred Computed Tomography (CT) data of hip joint of Indian patients were collected
from different hospitals. Utilising the Materialise's Interactive Medical Image Control System
(MIMICS) software, CT data were processed for study of important osteological parameters.
These osteological parameters were further measured from CT data using 3-Matic software
and suitably tabulated. The entire database was very much useful in due course for detail
design of femoral prosthesis, suitable for Indian population.
Keywords: hip joint, proximal femur, Total Hip Replacement, Implant size, hip prosthesis,
morphology, CT, proximal femur
4th National Conference on Advances in Metrology - AdMet2015 HC-8
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MIC – Dilutions and Dynamics
Indranil Roy, Dr. Rajat Mukherjee SRL Lab, Kolkata
E-mail: [email protected]
Minimum inhibitory concentrations (MICs) are defined as the lowest concentration of
antimicrobial that will inhibit the visible growth of a micro-organism after overnight
incubation, and minimum bactericidal concentrations (MBCs) the lowest concentration of
antimicrobial that will prevent the growth of an organism after sub-culture on to antibiotic
free media. MICs are used by diagnostic laboratories, mainly to confirm resistance, but most
often as a research tool to determine the in-vitro activity of new antimicrobials, and data from
such studies have been used to determine MIC breakpoints. MBC determinations are
undertaken less frequently and their major use has been reserved for isolates from the blood
of patients with endocarditis. The range of antibiotic concentrations used for determining
MICs is universally accepted to be in doubling dilution steps up and down from 1 mg/L as
required. These measurements are done according to established guidelines from CLSI,
EUCAST or BSAC. The determination of the appropriate interpretive criteria regarding
establishment of breakpoints involve the generation of three distinct types of data e.g. MIC
population distributions of the relevant microorganisms, pharmacokinetic parameters and
pharmacodynamic indices of the antimicrobial agent, results of clinical trials and experience.
The interpretation of the data involves creating a scattergram from the bacterial population
distribution (representative bacterial species), by plotting the zone of inhibition against the
logarithm to the base 2 of the MIC for each bacterial pathogen. The development of a concept
known as ‘microbiological breakpoints’, or ‘epidemiological cut-off values’, which is based
on the population distributions of the specific bacterial species tested, may be more
appropriate for some antimicrobial surveillance programmes. In this case, bacterial isolates
that deviate from the normal wild-type susceptible population would be designated as
resistant, and shifts in susceptibility to the specific antimicrobial/bacterium combination
could be monitored. There is a great advantage in the recording of quantitative susceptibility
data in that such data may be analysed according to clinical breakpoints as well as by using
epidemiological cut-off values. There are various methods for testing MIC. These include
broth and agar dilution techniques, E test, automated systems which detect bacterial growth
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by turbidimetric or fluorometric measurements. The aim of the broth and agar dilution
methods is to determine the lowest concentration of the assayed antimicrobial that inhibits the
visible growth of the bacterium being tested (MIC, usually expressed in μg/ml or mg/litre).
However, the MIC does not always represent an absolute value. The ‘true’ MIC is a point
between the lowest test concentration that inhibits the growth of the bacterium and the next
lower test concentration. Therefore, MIC determinations performed using a dilution series
may be considered to have an inherent variation of one dilution. Antimicrobial ranges
encompass both the interpretive criteria (susceptible, intermediate and resistant). Dilution
methods appear to be more reproducible and quantitative than agar disk diffusion. However,
antibiotics are usually tested in doubling dilutions, which can produce inexact MIC data.
Bacterial antimicrobial MICs can also be obtained using commercially available gradient
strips that diffuse a predetermined antibiotic concentration. However, the use of gradient
strips can be very expensive and MIC discrepancies can be found when testing certain
bacteria/antimicrobial combinations compared with agar dilution results. The automated
systems overcome the disadvantage of labour intensive protocols of manual methods only to
be limited by their expense. The latest development in the MIC measurement involves a rapid
(4-hr) electrical method for Antibiotic Susceptibility Testing that not only yields the MIC of
candidate antibiotics, but also simultaneously determines the antibiotics’ effect on the
bacteria (bactericidal/bacteriostatic). The currently available systems like VITEK (from
Biomeriux) , Phoenix (Becton-Dickinson) and the Microscan WalkAway (Siemens) lack
these advantages. Newer methods being developed include those using dielectrophoresis
(DEP), microfluidic incubation, magnetic bead rotation sensors. However each of these
methods has its own limitations. The use of genotypic approaches for detection of
antimicrobial resistance genes has also been promoted as a way to increase the rapidity and
accuracy of susceptibility testing. They however may lack the ability to differentiate between
dead and live bacteria and may also fail to generate a quantitative result that may influence
drug dosage decisions. Standardized phenotypic AST methods will still be required in the
near future to detect emerging resistance mechanisms among bacterial pathogens and robust
QC methods need to be followed to ensure accuracy and reproducibility of the measurements.
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Characterization of Micropipette and Its Uncertainty Evaluation
Goutam Mandal*, Anil Kumar and Dinesh Chandra Sharma
CSIR – National Physical Laboratory, New Delhi, India
* E-mail: [email protected]
Micropipettes or piston pipettes (see Fig.1 & 2) are very handy instruments for handling very
small amounts of liquid and these are used mainly in chemical, pharmaceutical and medical
laboratories. The principle of dispensing of liquid is simple. A disposable tip, usually made of
polypropylene plastic, is attached to the piston pipette, with the piston at the aspiration lower
limit the tip dipped in the liquid. When moved to the aspiration upper limit, the piston
aspirates the liquid.
Fig. 1 & 2 : Single channel piston
In order to identify and reduce possible errors in intensive liquid handling process, it is
necessary to calibrate the micropipettes to ensure correct delivery of liquid. Gravimetric
method used for determining volume using distilled water at reference temperature of 27 °C
in Indian Continent (tropical country) as per eq. (1).
𝑉𝑉27 = (𝐼𝐼𝐿𝐿 − 𝐼𝐼𝐸𝐸) × 1𝜌𝜌𝑊𝑊−𝜌𝜌𝐴𝐴
× 1 − 𝜌𝜌𝐴𝐴𝜌𝜌𝑩𝑩 × [1 − 𝛾𝛾 ∙ (𝑡𝑡 − 27)] (1)
where, IL : Balance reading of vessel with water, in g
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IE : Balance reading of empty vessel, in g (zero in case the balance was tared
with the volumetric instrument)
ρA : Density of air, in g/ml
ρB : Either the actual density of the balance weights when these are adjusted to
their nominal mass, or the reference density for which the weights have
been adjusted, in g/ml
ρW : Density of water at t °C, in g/ml, calculated with the “Tanaka” formula
γ : Coefficient of cubical thermal expansion of the material of which the
volumetric instrument tested is made, in /°C
t : Temperature of water used in testing, °C
“Z factor” is also very commonly used for determining volume of micropipette. But it is
not correct to convert mass value (in mg) of water to volume (in µl) just by multiplying “Z
factor”. Because “Z factors” are available at reference temperature of 20 °C and it should be
converted from 20 °C to 27 °C according to reference temperature in our country.
Deviation from the nominal value (systematic error) should meet the requirements of ISO
8655-2 : 2002.
Standard uncertainties of measurement associated with the volume, V27 are calculated
using sensitivity coefficients as per ISO/TR 20461 : 2000. Expanded uncertainty is calculated
by multiplying the combined standard uncertainty, uc by a coverage factor, k. Determined
expanded uncertainty (random error) also should meet the requirements of ISO 8655-2 :
2002.
There are two types of micropipette - single channel and multichannel. A complete
example of single channel piston is given in this paper, since, it is very commonly used.
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Molecular Interactions of Cyclodextrin Molecules with 5-
Enolpyruvylshikimate-3-Phosphate Synthase as a Tool for Biosensor
Applications
R. Navanietha Krishnaraj and Sudit Mukhopadhyay Department of Biotechnology, National Institute of Technology Durgapur
E-mail: [email protected]
Environmental pollution is one of the huge menaces to the human community. It arises from
various activities of mankind. Due to rapid industrialization and advancements in science and
technology, the use of chemical pesticides has increased to several folds nowadays. The use
of these herbicides is necessary to meet the global food shortage issues because of the
overwhelming population. The currently available herbicides have several disadvantages.
Among the various pesticides, glyphosate is more commonly used herbicide to control a
broad range of herbs. However, the use of these chemical pesticides leads to environmental
deterioration. They affect the aquatic ecosystems, microbial community in soil, besides
affecting the health of terrestrial organisms including human beings. Hence herein, we report
a green approach for controlling the weeds using cyclodextrin molecules. Inhibition of
enolpyruvylshikimate-3-phosphate (EPSP) synthase enzyme in the shikimate pathway
hinders the production of aromatic amino acids such as phenylalanine, tyrosine and
tryptophan in the weed. EPSP synthase is a good target for screening herbicides. Docking
investigations were done with AutoDock Vina algorithm to assess the binding of the α-
cyclodextrin, β- cyclodextrin and γ- cyclodextrin to the target. The ligands namely α-
cyclodextrin, β- cyclodextrin and γ- cyclodextrin have higher binding energies of -13.7,-12.6
and -17.3 with EPSP synthase when compared with the glyphosate ligands. Among the three
different stereoisomers of cyclodextrin, the γ- cyclodextrin had 3.2 times higher binding
affinity when compared with the glyphosate ligands. This investigation paves the new path
for biosensing and highthroughput screening of potential herbicidal ligands in an eco-friendly
approach.
Keywords: Ligands, herbicides, Biosensing, high throughput screening
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Molecular Docking and UV-Visible Spectroscopic Investigation of Anti-
Cancer Drug Nimustine Interaction with Calf Thymus DNA
Deepti Chadha, Shweta Agarwal and Ranjana Mehrotra
Quantum Optics and Photon Physics, CSIR-National Physical Laboratory, New Delhi, India
E-mail: [email protected]
DNA is a potential cellular target for many cytotoxic anticancer drugs for the ability of the drugs to
modulate DNA replication, transcription and/or repair after binding with it. However, the mode of
interaction of most of these drugs with DNA is not well understood and is still an area of active
research today. Nimustine, a chloroethyl nitrosourea derivative (CENU), is an antineoplastic agent,
which is used for the treatment of various types of cancer. The present study focuses on the prediction
and investigation of binding properties of nimustine with DNA using molecular modeling techniques.
Furthermore, UV-visible spectroscopic method was also used to explore the strength of the drug–
DNA complexes. In this perspective, in silico docking studies are carried out using AutoDock 4.2.
The results of the docking study show that nimustine plausibly binds within the major groove of
DNA. Further analysis of docking suggest direct interaction of nimustine with the moieties of
heterocyclic nitrogenous bases especially with groups C6=O6 (guanine) and C4=O4 (thymine) of
DNA. The free binding energy value of the selected nimustine-DNA docked conformer (lowest
energy conformer of the most populated cluster) is predicted as -4.31 kcal/mol using docking results.
The study also reveals that the interaction between nimustine and DNA is majorly governed by van
der Waals forces and hydrogen bonding, whereas the contribution of electrostatic forces stands
negligible. Further, UV–visible spectra of free calf thymus DNA and its complexes with varying
concentration of nimustine indicate the binding constant value as 3.27 x 103 M-1 suggesting moderate
interaction of nimustine with DNA. The spectroscopic results are further used to calculate the binding
free energy of the drug-DNA complex using the relation; ΔG = -RT ln (Ka), which accounts for a
value of -4.79 kcal/mol and corroborates well with the docking outcomes. The results of our present
study may help in designing of new chloroethyl nitrosourea derivatives with improved efficacy and
specificity for the target molecules.
Keywords: Nimustine, Drug-DNA interaction, Molecular modeling, UV-visible spectroscopy, docking
PS-II Time & Frequency
(TF)
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Achieving Higher Quality Factor of a Helical Resonator by Optimizing its
Impedance
S. Panja, N. Batra, A. Rastogi, J. Thangjam, S. Yadav, S. De, and A. Sen Gupta
CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi - 110012.
E-mail: [email protected]
Abstract: Helical resonators are commonly being used for delivering narrow bandwidth and high voltage radio frequency to RF trap for stable confinement of ions. Resonant frequency of a helical resonator at loaded condition depends on the capacitive load of the ion trap. Load capacitance of an ion trap can be estimated by studying the variation of the resonant frequency of the resonator for different load capacitances and a resonator can be constructed for desired resonant frequency. We demonstrated a very simple method to achieve higher Q-factor of a resonator by optimizing mutual separation between the primary antenna and helical coils.
Radio frequency (RF) driven ion traps are popularly used for trapping ions and the trapped ions have immense application in quantum information processioning, quantum simulation and frequency standards [1-3]. RF driven ion traps require high voltage (~kV) at high frequency in order to achieve large trapping potential i.e., longer trapping life time [4]. In NPL India, we are developing an optical frequency standard based on an ultra-narrow optical transition in single trapped Ytterbium (171Yb+) ion. For 171Yb+ ion the lowest lying excited state is (2D3/2) state and it decays to (2S1/2) ground state via an electric quadrupole transition at 436 nm. The excited (2D3/2) state is extremely long lived with lifetime of several years, which leads to an extremely narrow natural line width (3.1 Hz) of that transition. A Paul trap will be used to trap a single ytterbium ion and an oscillatory voltage at radio-frequency (~ MHz) will be applied to produce a harmonic-oscillator with frequencies of 1–2 MHz [2-3]. In order to trap a single Ytterbium ion (171Yb+) within a Paul trap, a narrow bandwidth at large amplitude ~1 kV peak-to-peak radio frequency (RF) voltage is applied to the electrodes. Wide frequency bandwidth results to unstable trapping and unwanted heating of the ions and direct delivery of high voltage RF to a trap damages the source due to impedance mismatch between source and the trap electrodes. A helical resonator allows impedance matching between a RF source and an ion trap, enabling high voltages while reducing the noise injected into the system.
The key components of helical resonators are a cylindrical copper tube as a shield, a helical coil, and a small antenna for coupling RF signal to the resonator. RF signal is coupled in one end of the helical coil and the other end is open circuited where the load, i. e., an ion trap can be connected. The artistic view of a helical resonator has been shown in the figure-1. Macalpine and Schildknecht [5] described in detail how the performances of a helical resonator depends on the shield diameter (D), shield height (H), diameter of the helical coil (d), height of the coil (b), diameter of the wire or tube of the coil (d0), the number turns in the helical coil (N) and the winding pitch of the coil (τ). Resonant frequency of resonator can be described as 0
01
2wf
LCπ= = , where
L and C are the inductance and the capacitance of the resonator. In our experiment the resonator will be connected to the ion trap and the resonant frequency not only depends on the parameters of the resonator but the capacitance of the trap as well as the connecting wires will also play major role on the resonant frequency. We have constructed an electro-magnetically shielded helical coil resonator which inductively couples the RF source to the ion trap. The resonator is constructed out of a copper tube which is winded in helical shape (secondary coil) and placed inside a larger diameter copper tube for RF shielding. The farthest end of the secondary coil is grounded through the surface of the shielding tube and the other end couples RF to the trap. An antenna coil (primary) is positioned coaxially farther away from the
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grounded end of the secondary coil. The coupling efficiency to the secondary coil depends on the construction parameters. We have adopted ratio of the secondary coil diameter d to the shielding tube diameter D is d/D ~ 0.55; length of the secondary coil is larger than d and outer diameter of the construction tube of the secondary coil is approximately half of its pitch.
Delivering the high voltage RF with a resonator will filter the noise, reducing the contribution to ion heating. In order to maximise the filtering of this noise, the resonator must have a high Q factor, and hence a narrow bandwidth. In this work, we have studied the dependence of Q factors with the f primary coil’s parameters and tried to optimize the Q factor of the resonator without changing its resonant frequency.
Fig: Artistic view of the Helical Resonator with inner helical coil and the primary coil to fed the RF signal into the resonator Impedance mismatch between the RF source and the ion trap will reduce the efficiency of delivering RF Voltage to the trap as the signal will be reflected back form the trap and the power will be dissipated over the output impedance of source. Impedance mismatch between the RF source and the trap can be optimized by changing number of turns and pitch of the primary coil [6]. In our study we have shown that the impedance matching can also be achieved by adjusting the position of the primary coil with respect to secondary helical coil of the resonator and in that way highest Q factor for the resonator can also be achieved.
References: [1] J. I. Ciracand, P. Zoller, Phys. Rev. Lett. 74,
(1995) 4091. [2] A. Friedenauer, H. Schmitz, J. T. Glueckert, D.
Porras, and T. Schaetz, Nature Phys. 4, (2008) 757
[3] S. A. Webster, P. Taylor, M. Roberts, G. P. Barwood, and P. Gill, Phys. Rev. A, 65 (2002) 052501. [4] W. W. Macalpine, R. O. Schildknecht, Proc. IRE 47, 2099 (1959)
[4] W. Paul, O. Osberghaus, and E. Fischer. Forschungsbe. Wirtsch. -Verkehrminist. Nordrhein-Westfalen, 1958, 415
[5] W.W. Macalpine, R.O. Schildknecht, Proc. IRE 47 (1959) 2099
[6] J. D. Siverns, L. R. Simkins, S. Weidt, W. K. Hensinger, Appl. Phys. B, 107 (2012) 921.
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Ion Trap Design for the Optical Frequency Metrology at CSIR-NPL, India
S. De, N. Batra, A. Rastogi, J. Thangjam, S. Yadav, S. Panja, and A. Sen Gupta CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi - 110012.
E-mail: [email protected]
Abstract: Atomic clocks based on the narrow optical transitions lose 1 s in few ten billions of years, which are useful in sophisticated technology as well as for precision experiments. We are developing aytterbium-ion (171Yb+) optical frequency standard aiming to achieve fractional accuracy of ~10-17. Design of the ion trap and its associated ultra high vacuum chamber have been finalized and they are under fabrication. The suitable trap geometry is identified through numerical simulations to produce nearly ideal quadrupole trapping potential and systematic shifts produced therein. This study concludes that the octupole transition will give an order of magnitude higher accuracy than the other possible clock transitions in 171Yb+.
Precise Timing systems has applications in sophisticated technologies such as accurate positioning of satellites, locating missiles or targets, satellite based navigation, communication. However, exploring the fundamentals of science, as for example, experimental verification of the temporal constancies of fine structure constant or electron-to-proton mass, detecting variation of the gravitational potential at centimetre level require clocks with fractional accuracies better than 10-17. This motivates us to develop an optical frequency standard [1] which will provide two orders of magnitude better accuracy than the in-house developed and operational Cesium fountain clock with an accuracy of 2×10-15. The trapped ion optical frequency standard experiment includes photoionization of171Yb atoms to produce the ion, confining its motion using a Paul trap, laser cooling to mK temperature, high resolution detection of single ion and finally probing its highly forbidden hence ultra-narrow octupole transition at the wavelength 467 nm for using it as frequency standards. We have opted for the end cap trap geometry, as shown in Fig. 1,so that the trapped ion can be optically accessed by multiple lasers beams. The geometry of trap electrodes determine nature of the potentials that is particularly deviation of the desired quadrupole potential due to the contributions of higher order multipoles. These higher orders affect motion of the ion and hence the systematic shifts in the transition frequency. The most suitable trap geometry which can produce nearly ideal quadrupole trapping potential have been identified through numerical simulations. We have also estimated systematic shifts like Electric quadrupole, Doppler, Zeeman and Stark shifts for the clock transitions of 171Yb+, which signify achievable accuracy of the frequency standard. This study concludes that the
2 21/ 2 7 / 2; 0, 0 ; 3, 0F FS F m F F m= = − = = octupole transition
at wavelength 467 nm will give an order of magnitude higher accuracy than the other possible clock transitions in 171Yb+.
Fig. 1: Design of CSIR-NPL ion trap and its mount (left). Geometric specification of the trap electrodes (right) which specifies nature of the confining potential.
The ion remains confined in a potential Φ(x,y,z,t) produced by a combination of a dc, U, and ac, V cosΩt, electric fields, Vt = U + V cosΩt,in an end cap type Paul trap. Even though a harmonic potential is the ideal choice, some finite perturbations arise due to higher order multipoles. In our radially symmetric trap only even higher orders mutipoles contribute which need to be minimized for reducing systematic effects of an optical frequency standard. The numerically simulated potential together with harmonic and higher order anharmonic components in it are shown in Fig. 2. The most suitable trap has been identified as 2ro=1 mm, 2r1=1.4 mm, 2r2=2 mm. 2zo=0.7 mm, 2z1=1.16 mm, θi=10o and θo=45o from different choices of the geometry dependent parameter (Fig. 1).
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Fig. 2: Potentials along (a) radial and (b) axial
directions of the trap. Numerically simulated data (green) is fitted to an anharmonic functions which consists of quadrupole (blue), octupole (red), dodecapole (cyan), sedecapole (magenta) and icosapole (black), respectively.
The projected systematic uncertainties of our single trapped ytterbium-ion optical frequency standards are estimated for the quadrupole (E2) and octupole (E3) clock transitions of 171Yb+ [2]. Finite temperature of the ion and its interaction with the external fields introduce shift in the measured frequency compared to its absolute value. Frequency shifts due to electric quadrupole moment, induced polarization and excess micromotion of the ion depend on electric fields. Electric quadrupole shifts, resulting from the electric field gradient of the harmonic potential, along three mutually orthogonal directions cancels each other. However anharmonic potentials produced by the trap electrodes also result in a non-vanishing electric field gradient, which introduces uncertainty in the measurement and that we have considered in our systematic shifts estimation. The shifts due to the anharmonic components of the potential become significant when the ion is trapped at few micron offset from the true trap centre. We plan to incorporate two pairs of counter acting compensation electrodes in the radial plane for accurate positioning of the ion. For a laser cooled ion the first order Doppler shift is zero, however the second order of it is non-negligible for frequency standards. Second order Doppler shifts originating from the stray
electric field and relative phase difference of the rf applied on opposite electrodes introduce orders of magnitude higher systematic uncertainty than the velocity of the ion at mK temperature. In order to achieve a frequency standard with ~10-17 fractional accuracy, the stray electric fields and phase difference needs to be controlled below 20 mV/mm and 0.8 mili-radian, respectively. Magnetic field induced shift and Stark shifts due to electro-magnetic radiation at a surrounding temperature are also estimated. At room temperature the dc Stark shift due to the black body radiation amounts to be -5×10-16 and -10-16 for the E2 and E3 transitions, respectively. At some amplitudes of the rf, higher harmonics of the fundamental secular frequency of the trapped ion matches with its oscillation frequency at the higher order multipole potentials. This nonlinear resonances causing the trapped ion to acquire excess energy lead them to escape from the trap. For single ion, these voltages ought to be avoided for performing the experiment. We have estimated these voltages at a series of rf [3].
In conclusion, the inhouse desing of the end capion trap and its associated ultra high vacuum chamber is under fabrication. Dynamics of the trapped ion in our trap and expected systematic shifts have been estimated. We are developing the optical setups for photoionization, laser cooling and fluorescence detection of the trapped ion. The current status on the way of developing the single trapped ion optical frequency standards using the
2 21/ 2 7 / 2; 0, 0 ; 3, 0F FS F m F F m= = − = = octupole clock
transition of the ytterbium ion will be discussed.
REFERENCES:
[1] S. De, N. Batra, S. Chakraborty, S. Panja, and A. Sen Gupta, Current Science 106, 1348 (2014).
[2] N. Batra, Sukhjit Singh, S. De, Amisha Arora, Bindiya Arora, A. Sen Gupta, Communicated (2014).
[3] N. Batra, S. De,A. Rastogi, S. Panja, S. Yadav, A. Sen Gupta. Communicated (2014).
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A Novel Technique for Precise Phase and Frequency Measurement
Aishik Acharya*, P. Arora, S. Yadav, S. Majhi and A. Sen Gupta
Time & Frequency Division, CSIR-National Physical Laboratory,
Dr. K. S. Krishnan Road, New Delhi – 110012
E-mail: [email protected]
Abstract: A novel technique for precise phase and frequency measurement is described in this paper. A primary frequency standard, namely, Cs atomic fountain has already been developed at CSIR-NPL. Sixcommercial Cs atomic beam clocks along with a H-Maserare continuously inter-compared and constitute a stable time scale. H-Maser frequency is being evaluated with respect to the Cs fountain on regular basis. For evaluating the frequencies of these different frequency sources precisely, a stable, low noise and very accurate frequency measurement instrument is required. All digital implementation of dual mixer time difference technique is a step towards more precise measurement and evaluation of frequencies and will provide better stability to the timescale.
1. Introduction
A simple way to measure frequency is using a frequency counter. But the main problem with such counters is the measurement time. For better resolution we need to measure for a longer time. Time interval counter method and heterodyne methods have been adopted for better resolution but they have their own limitations. Dual mixer time difference (DMTD) technique overcomes limitations of most of existing methods of frequency measurement [1-2]. Commercially available analog DMTD systems are capable of measuring frequency with higher resolution. But, the main problem with these analog systems is the complexity for processing the signal.
In this paper we will discuss the basic working principle and experimental set-up for digital implementation of this process.
2. Basic Principle of DMTD Technique
DMTD method relies upon the phase measurement of two incoming signals versus an auxiliary one, called common offset reference oscillator. Phase comparisons are performed by means of double-balanced mixers [3]. It is based on the principle that phase information is preserved in a mixing process. A block diagram is shown in Fig. 1.
DMTD technique combines the features of Beat Frequency Method and Time Interval Counter Method. Using a time interval counter to measure the relative phase of the beat signals, the measurement resolution is increased by the heterodyne factor (the
ratio of the carrier to the beat frequency). For example, mixing a 5 MHz source against a 5.000005 MHz Hz offset reference will produce a 5 Hz beat signal whose period variations are enhanced by a factor of 5MHz/5Hz = 106. Thus, a period counter with 100 ns resolution (10 MHz clock) can resolve clock phase changes of less than 0.01 ps.
Figure 1: DMTD block diagram.
3. Digital implementation of DMTD technique
In digital implementation of DMTD technique [4, 5, 6] the down-conversion performed by the analog mixers in Fig.1 is replaced by digital sub-sampling of the clock signals. The result of this operation is a digitized signal which is a sinusoidal waveform at a much lower frequency than the original clock signal. Like frequency mixing, the sub-sampling operation preserves the phase information at the beginning ofeach measurement which is the main interest in case of phase-difference measurement. After sub-
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sampling the digitized data is then further acquired and processed by computer.
In all digital implementation of DMTD technique subsampling process is done by high speed sample and hold analog to digital converters and the sampling clock is generated from the 5MHz reference using direct digital synthesizer.
Figure 2: General block diagram for digital implementation of DMTD technique.
The entire scheme of operation is described in Fig. 2. The sub-sampled digital data is then acquired by high speed data acquisition system and further processed by PC for precise phase measurement system.
Figure 3: Proposed three channel all digital dual mixer time difference technique.
A multichannel approach is shown in Fig. 3. Due to high scalability of the digital implementation of DMTD technique, multichannel phase comparison can easily be achieved between several clocks with a cost effective solution.
4. Summary:
A novel technique for precise phase measurement system has been described in this paper. Due to the high resolution such device can easily be used in precision measurement of microwave and optical frequency standard.
5. References: [1] D.W. Allan and H. Daams, “Picosecond time difference measurement system,” Proc. 29th Annu. Symp. Frequency Contr., Atlantic City, NJ, pp. 404-411, May 1975. [2] L.S. Cutler and C.L. Searle, “Some aspects of the theory and measurement of frequency fluctuations in frequency standards,” Proc. IEEE, 54(2), 136-154, 1966.
[3] “TSC 5110A time interval analyzer,” User Manual, Timing Solution Corporation, April 2001. [4] “Model A7 frequency and phase comparator,” Users Handbook, Quartz lock Instruments, July 1998. [5] S. Römisch, T. E. Parker and S. R. Jefferts, “NOVEL, ALL-DIGITAL PHASE MEASUREMENT SYSTEM FOR TIME SCALES”, 41stAnnual Precise Time and Time Interval (PTTI) Meeting.
[6] L. Sojdr, J. Cermak and G. Brida, “Comparison of high-precision frequency -stability measurement systems, Proceedings of the 2003 IEEE International Frequency Control Symposium and PDA Exhibition Jointly with the 17th European Frequency and Time Forum
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Current Updates on Primary Frequency Standards at CSIR-NPL, India
P. Arora*, A.Acharya, V. Bharath, S. Yadav, A. Agarwal and A. Sen Gupta
Time & Frequency Section, CSIR - National Physical Laboratory
Dr. K. S. Krishnan Road, New Delhi – 110012
E-mail: [email protected]
National Physical Laboratory, India (NPLI) has developed its first Cesium atomic fountain
frequency standard (NPLI-CsF1). The indigenously developed fountain frequency standard
is now fully operational and its frequency is now being evaluated along with all systematic
and statistical uncertainties. Seven frequency evaluation have been recently conducted to
estimate fountain frequency with respect to TAI (International Atomic Time). The fountain
frequency is compared with the Hydrogen Maser (H-Maser) frequency which is contributing
to TAI (International atomic timescale) and hence fountain frequency is evaluated with
respect to the TAI. The fountain frequency is stable to few parts in 1015 at less than one day
averaging time. A 2nd generation Cs fountain is also being developed with novel design
features in order to have better stability and accuracy than the first fountain.
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Development of VCO based Drivers for AOM and EOM
J. Thangjam, N. Batra, A. Rastogi, S. Yadav, S. De, S. Panja and A. Sen Gupta CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg,New Delhi - 110012.
E-mail: [email protected]
Abstract: Acousto-optic modulator (AOM) and electro-optic modulator (EOM) driven by voltage controlled oscillator (VCO) are widely used to control and modulate laser output, especially for semiconductor lasers. A wide range of tunabilty of the laser frequencies can be achieved in combinations of AOMs and EOMs. Here we are reporting about the development of very simple and cost effective VCO based driver for the optical modulators. These drivers work in the high frequency to ultra-high frequency region and can modulate the laser frequencies by few MHz to several GHz. A Phase locked loop is involved for achieving low phase noise and high frequency stability of the drivers output.
Modulation of the output frequencies of the lasers can be achieved with AOMs and EOMs and a wide range of tunabilty of the laser frequency can be achieved in combinations of AOM and EOMs. AOMs are usually deployed for modulating laser frequencies by several hundred Megahertz, whereas EOMs are useful for modulating laser frequency in the range of several GHz. One of the critical issues about working with AOM and EOM is unavailability of good quality of the shelf drivers for those modulators. We are developing AOM and EOM drivers for achieving low phase noise and ultrastable laser frequency with wide range of tunability. The drivers are made with VCOs and applicable in the high frequency to ultra-high frequency region. Integrating VCOs output frequencies with AOM and EOM, laser frequencies can be modulated by few MHz to several GHz.
In AOM a piezoelectric transducer is attached to a glass and when an AC signal is applied into the transducer it starts oscillating and results in a sound wave inside the glass that causes periodical contraction and expansion of the medium. Periodic modulation of refractive indices of the medium because of the acuosto optic wave will cause scattering of the incoming light and interference occurs similar to Bragg diffraction. In an AOM the light scattered from successive wave fronts interferes constructively and the frequency (f) of the diffracted beam in mth order will be Doppler shifted by an amount equal to the frequency of the sound wave (F) f f mF→ + .On the other hand in EOM electro-
optic effect is used to modulate the phase, frequency and amplitude of light beam and EOMs are very commonly used for frequency modulating in the gigahertz range. Inside a nonlinear optical material an
incident static or low frequency optical field will see a modulation of its refractive index. The EOMs are made of electro optic crystal and its refractive index is a function of the strength of the electric field. The phase of the light exiting from an EOM can be controlled very precisely by modulating the refractive index of the medium and the phase should have a linear dependency on the applied electric field. Application of an ac field on the electro optical material will add some time dependent phase as the refractive index changes with the field, which will results in additional frequencies co-propagating all together with the principle laser frequency. Finally many of the side band will appear and their separation will depend on the frequency of the ac field and the intensity will be much less for the higher order side bands.
The core of this driver is a VCO, an electronic oscillator circuit and its oscillationfrequency can be tuned within certain range by changing its input voltage. This tuning voltage can be controlled with a 12 bits input digital to analog converter (DAC) and the output of the DAC is connected to a differential amplifier. With proper combinations of the input bits and reference voltages of the DAC, regulated output voltage can be achieved from the amplifier. The output RF frequency of the VCO is connected to a pre-amplifying stage through an attenuator and finally a broad band amplifier is used for generating 1-2 watt output power for driving the AOM and EOMs. A schematic description of the VCO based optical modulator driver has been shown in fig-1.An attenuator will control the output signal of the VCOs and finally fed the signal to another amplification unit before sending it to the optical modulators. The input voltage of the VCO can be tuned to generate desired
4th National Conference on Advances in Metrology - AdMet2015 TF-5
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RF frequency from the VCO and the RF power can be controlled with the combination of the attenuator and amplifiers.
One of the key issues about generating such high frequencies with VCOs is the instability in the output frequency. While we are generating frequencies ~ GHz with VCO, we have to make sure that uncertainty of the output frequency should notbe more than 10 MHz. To achieve such a high level of accuracy we have designed a high-performance Phase-Locked Loops (PLL) with VCOs
FIG-1. Schematic diagram of the VCO based AOM/EOM drivers
References:
1. F. Allard, I. Maksimovic, M. Abgrall and Ph. Laurent Rev. Sci. Inst.75 (2004) 54 2
2. John D. Jost, John L. Hall, and Jun Ye, Optic Express10 (2002) 515
3. P. D. McDowall and M. F. Andersen Rev Sci. Inst. 80 (2009) 053101
4. A. Sen Gupta, A. Agarwal, P. Arora and K. Pant, Current Science100 (2011) 1393
5. A. Banerjee, D. Das, U. D. Rapol and V. Natarajan, Applied Optics 43 (2004) 2528
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Instrumentation for Atomic Clock Experiments
A. Roy*, A. Rastogi, N. Batra, J.Thangjam, A. Acharya, S. De$, P. Arora, S. Panja and A.
Sen Gupta CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi - 110012, India.
E-mail: [email protected]*, [email protected]$
The time and frequency division at CSIR-NPL is developing the first optical frequency
standard in India with a single trapped 171Yb+1 ion. This experiment requires a large number
of sophisticated electronic modules such as a laser frequency stabilization system, data
acquisition system to acquire and analyze the experimental data, electronic addressing system
for individual control of a large number of modules from PC, well regulated wide range
power supplies to name a few. In this paper, we describe some of the electronic components
that have been designed and fabricated in house at low cost.
4th National Conference on Advances in Metrology - AdMet2015 TF-7
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Indigenous Discharge Lamps for Rb Atomic Clocks
1Ashish Agarwal, Jayenta S Thangjam and A Sen Gupta Time and Frequency Division,
CSIR-National Physical Laboratory,
Dr. K. S. Krishnan Road, New Delhi 110012, India 1E-mail: [email protected]
Rubidium atomic clocks, being flown on satellites of Indian Regional Navigational Satellite
System (IRNSS), utilize the light from RF-discharge lamps for atomic signal generation and
detection. The performance and life of the atomic clocks and the capabilities of the
navigational system depend sensitively on the lamp’s stability and performance. The Rb
discharge lamp is a strategic technology available with the US, and the space agencies of
Europe, Russia and China. In India, we are developing this technology with the help of Indian
Space Research Organization. We have been successful in developing these lamps
indigenously. This paper reports the studies done on studying the performance of these
lamps. Our studies establish that composition of glass used in making the lamps critically
decides the life of the lamp.
4th National Conference on Advances in Metrology - AdMet2015 TF-8
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Analogue Modulation Measurement
Biswanath Mondal
Scientist “D”, ERTL(E)
Analogue Modulation is being used in Radio Communication, Broadcast & Civil Aviation
Industries for ages. Amplitude, Frequency & Phase Modulations have been widely talked
about subjects, since long, although Amplitude Modulation was historically the oldest type
of Modulation. Even Signal Generators are having Analogue Modulation feature, apart from
its Digital Modulation counter parts. As such, the need for accurate measurement on
Analogue Modulation, such as Amplitude Modulation Index measurement was strongly felt.
Depending on the technique of measurement, the Measurement Uncertainty varies from a few
percentages to about 0.5% at the maximum. Measurements can be carried out either by using
Oscilloscopes in the Time domain or Spectrum Analyser in the Frequency Domain by
appropriately setting the Resolution & Video Bandwidths. The Frequency Modulation
measurements, particularly measurement of certain level of deviations, require the use of the
principle of Bessel Nulls & mathematical analysis with the help of Bessel Functions. The
present paper has attempted to explain the techniques of such measurements for modulated
waveforms.
PS-III Electro Technical
(ET)
4th National Conference on Advances in Metrology - AdMet2015 ET-1
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Traceability of Precision HV Resistive divider by Binary method
K. B. Ravat
CSIR-National Physical Laboratory, New Delhi 110012
E-mail: [email protected]
This paper focused on an evolution technique and traceability for a DC resistive high voltage
divider was established based on 1kV, which was traceable to Josephson voltage standard.
Binary step up method was used to evaluate the voltage dividing ratio and voltage coefficient
of the divider up to 100 kV. The expended relative uncertainty for the voltage divider up to
100kV was 16 X 10-6. To confirmed the validity of the divider and two results are within 5.3
X 10-6.
4th National Conference on Advances in Metrology - AdMet2015 ET-2
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Evaluation of Four-Terminal-Pair Air Capacitance Standards at CSIR-
NPL
Satish*, Babita and A. K. Saxena
LF, HF impedance and DC Standard, CSIR-NPL New Delhi-110012
E-mail: [email protected]
The present paper reports the work performed in the direction of establishment of
metrological traceability of high frequency capacitance standards at CSIR-NPL. The four
terminal pair air capacitance standards of Agilent 16380A set with nominal values of 1 pF, 10
pF, 100 pF and 1000 pF are used as reference standards at CSIR-NPL and other NMIs
worldwide. The proposed technique evaluates these standards by extrapolating the reference
capacitance at 1 kHz to higher frequencies upto 30 MHz.
4th National Conference on Advances in Metrology - AdMet2015 ET-3
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Measurements of UV-A Radiation and Hazard Limits from Some
Types of Outdoor Lamps
Essam El-Moghazy*, Alaa–Eldin Abd-Elmageed, and Sameh Reda
Photometry and Radiometry division, National Institute for Standards (NIS),
Giza, Egypt. *E-mail: [email protected]
Illumination using artificial light sources is common in these days. Many manufactures are
paying for the design of lamps depending on high efficacy and low UV hazards. This
research present the study of three types of HID lamps, which are most useable lamps in the
Egyptian markets; High Pressure Mercury (HPM), Metal Halide (MH), and High Pressure
Sodium (HPS), from OSRAM in terms of their irradiance and spectral power distribution for
ultraviolet radiation
present in their emitted radiation. The lamps was aged according to IES publication then each
lamp aligned at 50 cm in front of the integrating sphere entrance slit of a system based on
MS257 single monochromator from Newport Corporation. The system was adjusted to
acquire readings at the range from 200nm to 800nm with step 2nm, also this monochromator
bandpass was adjusted nominally at 4 nm resulting slit function uncertainty ±0.34 %at k=2.
The absolute spectral irradiance level of each lamp in the UVA range at 50cm is measured
using a calibrated radiometer model 268 UVA from UDT Company and their accompanied
standard uncertainty are evaluated. Results show that HPM emits the largest amount of UVA
compared with MH and HPS lamps. While HPS emits the lowest amount with moderate
amount was from MH lamp. It is noticed that the safety distance is proportional with the
amount of UVA emission. Hence, it is highly recommended to use these lamps only in
outdoor, as they may be lie in the range of the CIE hazard condition if used indoor.
Key words: Artificial sources; Illumination; UVA radiation; Irradiance; Uncertainty.
4th National Conference on Advances in Metrology - AdMet2015 ET-4
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Performance Analysis Study on the Calibration Data of Frequency
Counter
Archana Sahu, Bijendra Pal, Saood Ahmad, P.S. Negi & V.N. Ojha LF & HF Voltage, Current and Microwave Standards
Apex Level Standard and Industrial Metrology
CSIR- National Physical Laboratory, New Delhi, India.
E-mail: [email protected]
National Physical Laboratory (NPL) India is the premier research & development centre and
the National Metrology Institute (NMI), which provides traceability in measurements by
calibration throughout the country. Frequency is one of the important parameter in Electrical
metrology. Digital frequency counting is invariably the simplest and accurate method of
measurement and display of frequency. In this calibration technique either reference
frequency counter or synthesized frequency source is locked to the standard frequency signal
synchronized to the cesium (Cs) atomic standard; the primary standard of time and frequency.
The uncertainty of reference standard frequency counter upto 40 GHz is ±1x10-10. The
calibrated results of a frequency counter calibration have been discussed in this paper. The
long term performance study carried out on the calibration data of a frequency counter over a
period is reviewed in this paper. The results show that the maximum deviation in the
calibration results from the mean value obtained over the period of calibration from 10 Hz to
100 kHz is within ± 0.000015% and from 1MHz to 1 GHz is within ± 0.0000005%.
4th National Conference on Advances in Metrology - AdMet2015 ET-5
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Effect of Burden on Potential Transformer
M.K. Tamrakar, L. Sridhar, Shrikrishan and M.A. Ansari
AC High Voltage and High Current Standards
CSIR – National Physical Laboratory, New Delhi – 12
E-mail: [email protected]
NPL maintains National Standards for AC High Voltage and High Current Ratios at power
frequencies (50Hz) by using Reference Standard High Voltage Ratio Measuring System
(HVRMS) and Reference Standard Current Transformers and also maintaining the National
Standards for the calibration and measurement of AC High Voltage Capacitance and Tan δ
upto 200kV at 50Hz by using Reference Std. Capacitors & High Precision C & Tan δ
Measuring System. This paper reports the performance of Potential Transformer (PT)
evaluated by comparison method, which is accomplished by standard PT and Automatic
Instrument Transformer Test Set (AITTS). In this comparison method, the ratio of the
standard PT and PT under test (DUT) should be same. The rated high voltage is applied
parallel to DUT and standard PT. The secondary side of the PTs is connected to the AITTS.
The AITTS compares the secondary voltages and gives the ratio error and phase angle. The
PT burden is then inserted in parallel to the secondary side of the DUT. The performance of
the DUT is thus evaluated at different burdens. The DUT having ratios 6.6 kV-11kV-
22kV/110V is evaluated for the ratio 11kV/110V against the standard PT of same ratio at
different burdens. In this paper, the effect of burdens on the performance of the DUT will be
presented.
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Analysis of the Stability of the Zener Based Reference DC Voltage
Standard
Sandhya M. Patel, Anish M. Bhargav and V.N. Ojha CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi-12
E-mail: [email protected]
In this paper, we report the stability of output voltage of the Zener based Reference DC
Voltage Standard at 10 V and 1.018 V (Fluke 732B). The long-term stability and the short-
term stability of the DC Reference Standard have been analyzed using the calibration data
obtained over a period of three years. The voltage values on the basis of the average drift
during the last few calibrations are also predicted. With this analysis, the reference standard
can be used for the calibration of other voltage standards and provides a mean to maintain
and disseminate a reference voltage.
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Development of LabVIEW Based Automation Setup to Analyze Insertion
Loss of RF Cable for Quantum Voltage Metrology
Anish Bhargav, Sandhya M Patel, Saood Ahmad, P.S.Negi and V.N.Ojha
CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi-110012
E-mail: [email protected]
Here, we present an indigenously developed automation setup based on LabVIEW to study
and analyze the insertion loss of RF cable at microwave frequencies. This RF cable will be
used to transfer the microwave frequency and power from the signal generator to the
sample/DUT (device under test) in Quantum Voltage Metrology. The attenuation
measurement discussed here is based on power ratio method whereby, the ratio of transmitted
and received power is used to measure the insertion loss. This automation setup has been
validated on two RF cables and the graph for insertion loss has been plotted. Developing the
automation software minimizes human involvement and therefore reduces chances of error
leading to high precision measurements. Also, the uncertainty budget for insertion loss
measurement based on GUM/ISO 17025 document is discussed.
4th National Conference on Advances in Metrology - AdMet2015 ET-8
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Power Calibration System (PPCS)
a Primary Standard of AC Power & Energy
M. K. Mittal1, J.C.Biswas2, .K.P.S.Yadav3 A.S.Yadav4, R.P.Agarwal5 and S. S. Rajput6
1Chief Scientist and Advisor, 2Sr. Principal Scientist, Head, 3Sr. Superintending Engineer, 4Sr. Technical Officer and deputy activity leader for AC Power & Energy and AC High
Voltage & High Current Standard, National Physical Laboratory , New Delhi – 110012,
India, 5Faculty of Electronics, Informatics & Computer Engineering, Shobhit University,
Meerut – 25011, 6Chief Scientist and head, Material Physics and Engineering Division, National Physical
Laboratory, New Delhi- 110012
This paper is related to the establishment of a Primary Standard of AC Power & Energy.
This is traceable to Voltage, resistance (current in effect) and time. Two digitalized AC
signals are generated one for voltage and the other for current. The signals are converted in
analog signals by D/A converters. The voltage signal is amplified and applied to device under
calibration (DUC) and for measurement, applied to a step down transformer, which is at same
level when it was generated. The current amplifier generates the test currents which is given
to the DUC and also to a current transformer (CT). The secondary side of the CT is burdened
with a shunt and again brought at the level when it was generated. The two signals are
measured by a Digital Multi-Meter (DMM) by a single clock signal. Then the two signals,
are compared through DMM. The phase between voltage and current is applied by time
delay.
Keywords: Primary Standard, Voltage , Current, Power Factor
4th National Conference on Advances in Metrology - AdMet2015 ET-9
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Analysis of An Accurate and Precise Two Port Waveguide Mismatch as An
Impedance Transfer Standard
Jyoti Chauhan, Naina Narang and S. K. Dubey CSIR-National Physical Laboratory, New Delhi-110012
E-mail: [email protected]
Impedance measurement is an essential requirement for evaluating and improving the RF
matching properties of microwave devices, components and subsystem. Transfer
standards are used to validate the accuracy and precision of impedance measurement
instruments/ systems. Set of mismatched loads are commercially available as the
broadband standards of RF impedance for one port instruments and Beatty standard
(verification Kit) as two port standard for the vector network analyser in coaxial
measurement systems. In this paper, we have reported the design and analysis of an
accurate two port waveguide mismatch which can be used as waveguide transfer
standard for establishing Vector network analyser (VNA) based waveguide measurement
facilities by the RF measurement laboratories.
PS-IV Metrology
for Advanced Manufacturing
(MAM)
4th National Conference on Advances in Metrology - AdMet2015 MAM-1
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Two Phase Flow Simulation and Experimental Validation of Semisolid
Slurry Generation Process of A380 Al alloy
Prosenjit Das*a,b, Sudip K. Samanta a, Pradip Duttab *a,b NNMT Group, CSIR-Central Mechanical Engg. Research Institute, Durgapur-713209, India.
bDepartment of Mechanical Engineering, Indian Institute of Science, Bangalore-560012, India.
*E-mail: [email protected]
A cooling slope (CS) is employed in the present work to produce semisolid A380 Al alloy
slurry, keeping in view of further in house processing of the slurry to develop automobile
components. Cooling slope facilitates heterogeneous nucleation, dendrite fragmentation and
shearing of the solidifying melt to produce nearly spherical, non-dendritic microstructure.
Cooling slope facilitates semi solid slurry generation with less processing time, simplicity
and cost-effectiveness. In this work, a numerical model has been developed to simulate the
liquid metal flow through cooling slope using an Eulerian two-phase flow approach. The two
phases considered in the present model are liquid metal and air. Solid fraction evolution of
the solidifying melt is tracked numerically at different locations of cooling slope using
Schiel's equation. The continuity, momentum and energy equations are solved considering
thin wall boundary condition approach. The purpose of numerical model development is to
understand the effect and to establish precise process control on temperature distribution,
velocity distribution and solid fraction of the solidifying melt. The numerical findings
obtained are complemented with experimental measurements of slurry temperature and slurry
microstructural features.
Keywords: Semi-solid slurry, Cooling slope, A380 alloy, Eulerian model, Two phase
4th National Conference on Advances in Metrology - AdMet2015 MAM-2
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Lubrication of Dry Sliding Contact by Functionalized Graphitic
Nanoparticles
Suprakash Samanta, Santosh Singh, R. R. Sahoo Surface Engineering & Tribology Division
CSIR-Central Mechanical Engineering Research Institute
Mahatma Gandhi Avenue, Durgapur, WB, India 713209
E-mail: [email protected]
Thin, adherent lubricating films are primarily used in precision sliding contacts where wear
debris formation is significant and demand for high reliability is requisite. Hence detailed
structural and compositional characterization of solid lubricants is of prime importance. To
act as a superior lubricant, the adherence of these nanoparticles to the region of contact
between the asperities of mating surfaces is of prime importance. Therefore functionalization
of the particles for better control of particle adhesion to the tribocontact is a key challenge
and also is needed to improve the frictional behaviour and assure long endurance lives. The
work focuses on using chemically functionalized graphite particles as the load bearing
candidates for efficient lubrication of dry sliding contact. Graphite was first oxidized to
obtain graphite oxide (GO), which is further chemically reduced to graphene. The graphite
oxide was again reduced and functionalized simultaneously by several organic moieties
having amine functionality. The frictional characteristics of all the particles were investigated
by pin/ball on disc tribometer at two different pressure regime. The particles were found to be
smeared effectively on the contact track under higher pressure and yield less coefficient of
friction compared to the lower pressure regime. The presence of organic chains on the
particle surfaces was found to have an effect on their lubrication behaviour. The particles
with superior wetting properties can have more adhesion to the surface and found to show
least coefficient of friction. The frictional characteristics of above particles in ambient
condition, their load bearing properties and lubrication mechanism are investigated.
4th National Conference on Advances in Metrology - AdMet2015 MAM-3
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3D Surface Characterization of Stainless Steel Microchannel Generated by
Electrochemical Micromachining
B. Ghoshal1, B. Bhattacharyya2 1Research scholar, Production Engineering Department, Jadavpur University, Kolkata-700032
E-mail: [email protected] 2Professor, Production Engineering Department, Jadavpur University, Kolkata-700032
Electrochemical micro-micromachining (EMM) is the key micromachining technology for
the manufacturing of ultra size components and micro-profiles with high quality surface. In
this paper, surfaces which are difficult to measure due to inaccessibility of contact probe are
characterized. The entry widths of microchannels were 130-140 µm. EMM was performed at
3V average voltage, 5 MHz pulse frequency and 34% pulse width on stainless steel with the
variation of electrolyte concentration of H2SO4. Measurement technique of surface parameters
of microchannels are described and measured parameters are analyzed for finding out most
suitable electrochemical micromachining parameters for better surface finish. Longitudinal
vibration of micro tool was also utilized with the amplitude of 0.5 µm and frequency of 85
Hz for improved surface finish. The lower roughness values are obtained at 0.2 M
concentration without vibration. There is well spread distribution of surface heights up to 0.2
M concentration as kurtosis value is smaller than 3.Vibration of micro tool with amplitude of
0.5 µm and frequency of 85 Hz further improved surface finish for all the concentrations of
electrolyte due to effective flushing. Lowest roughness values of Sa = 0.055 µm, Sq = 0.07
µm, Sz = 0.537 µm, Sp= 0.283 µm and Sv = 0.254 µm were obtained at 0.3 M concentration
with vibration of micro tool.
4th National Conference on Advances in Metrology - AdMet2015 MAM-4
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Further Optimization of Superior Quality Hydrogenated Diamond-Like
Carbon Anti-Reflection Coating for Silicon Solar Cell Application
Amit Banerjee and Debajyoti Das* Nano-Science Group, Energy Research Unit,
Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032, INDIA
*E-mail: [email protected]
ARC grade highly transparent hydrogenated diamond-like carbon (DLC) films were
produced, directly from a-C target, using RF magnetron sputtering deposition technique.
Optical band gap, transmittance, reflectance, refractive index, ID/IG ratio in the Raman
spectra and sp3 fraction of the films have been estimated with the help of tools like UV-vis
spectrophotometer, ellipsometer, micro-Raman and XPS. Optimum anti-reflection qualities
have been identified in low-temperature grown DLC films at a flow of Ar, F(Ar)= 3 sccm
and of H2, F(H2)= 9 sccm, at pressure (p)= 4 mTorr in the reactor, accomplishing its key
requirement for use in silicon solar cells.
Keywords: Anti-reflection coating; Diamond like carbon; Thin film; RF magnetron sputtering;
4th National Conference on Advances in Metrology - AdMet2015 MAM-5
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Study of Size Effects, Surface Quality and Elemental Characterization of
Different Crater Geometries on Titanium Alloy in Micro Milling
Vijay, Swapan Barman, Ram Prakash Sharma and Nagahanumaiah CSIR-Central Mechanical Engineering Research Institute, Durgapur
E-mail: [email protected]
Tremendous demand for micro parts and structures in electronics, aerospace, medical, bio-
medical and many other industries that produce micro or nano range patterns or components
with finer dimensional tolerances and quality surface integrity becomes a great challenge.
High precision machining technologies like micro milling, micro electrical discharge
machining, electro-chemical machining and laser machining are integrating the production of
micro parts in terms of unit volume removal in order of few hundred microns ensuring
reproduction in batch scale. But it is very difficult to control the dimensions and required
quality of surface finish of micro parts with different crater geometries. In this
communication, an attempt was taken to study the size effects and surface quality of crater
geometries like circular, triangular, square, rectangular, pentagonal, hexagonal, heptagonal
and octagonal machined in micro milling. Energy dispersive X-ray spectroscopy (EDS) was
used for elemental analysis of materials on the surfaces of crater geometries from Scanning
Electron Microscope (SEM) images. It was observed that there were variations in dimensions
on programmed values and finished products. Sharp edges were developed in micro craters
requiring further machining for assembling. Burrs were observed at the rims of the craters.
EDS study revealed that milling cutter material tungsten was deposited on the crater surfaces
deteriorating surface quality.
4th National Conference on Advances in Metrology - AdMet2015 MAM-6
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Experimental Investigation of Chatter in High Speed Milling
by Surface Metrology
Kamalkishor J. Uke1, Ranjan Sen2, S. B.Wadkar3 and M. C. Mujumder4 1,2CSIR-Central Mechanical Engineering Research Institute, Durgapur
3Sinhagad College of Engineering, Pune 4National Institute of Technology Durgapur
E-mail: [email protected]
Chatter can be termed as self-excited vibrations during machining; these vibrations can affect
the machine tool, the cutting condition, the work piece and the tool life. The effect of these
vibrations on machine tool can be disastrous. If the frequency of vibration coincides with the
natural frequency of the any mode of the machine tool, it may result in complete or partial
destruction of machine tool. Self- excited vibration which often occurs in machine tool
operations is known as regenerative vibration or chatter, since it originates by process itself.
The nature of force under dynamic condition acting on the tool point is again in turn
dependent on amplitude of vibration. The main causes of chatter are varying chip thickness,
varying rate of penetration of tool into job, variation in angular speed of job and surface
geometry or slenderness of the work piece. The chatter causes various effects that in turn
affect the machining process in form of high deformation of various members of machine,
reduction in the tool life, bad quality of finished products and considerable noise in the
vicinity. The above problem is most prominent in high-speed cutting with multiple point
cutting tool. Two main fields of research try to improve control of the process are prediction
and detection of chatter. Prediction techniques simulate behaviour of the machining system
and try to anticipate vibratory behaviour in order to compute optimal parameters for given
operation. (spindle speed, depth of cut etc.) The detection of chatter can be done in two ways,
Offline chatter detection and on-line chatter detection. This paper high lights the chatter
detection techniques by two phases; firstly by online and then by offline to validate the
findings. Online is done by vibration analysis and confirmation is done by surface profile
measurement both contact & non contact methods.
4th National Conference on Advances in Metrology - AdMet2015 MAM-7
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A Comparative Study on the 2D and 3D Surface Roughness of Direct Metal
Laser Sintered Ti6Al4V
1Sumanta Mukherjee,1Partha Saha,1Santanu Dhara.,2Ranjan Sen, 2Samik Dutta, 2Santanu Naskar
1IIT Kharagpur, Kharagpur-721302; 2CSIR-CMERI, Durgapur-713209
E-mail: [email protected]
Abstract:-On the Direct Metal Laser Sintered surfaces, if no post-treatment is applied, distinguishable sintered tracks, similar to the 'lay' for the machined surfaces, are found. Conventionally, while measuring 2D roughness of the surface, the measurement is taken across the direction of these marks. In this study, Ti6Al4V samples were prepared with different combinations of Direct Metal Laser Sintering parameters, and 2D and 3D roughness of the surfaces were compared. For the 2D measurements, three directions, namely, across the sintered tracks, along the sintered tracks, and at an angle of 45° with the tracks were chosen Comparing the trends of change in 2D and 3D average roughness with sintering parameters, it was found that measurements taken across the tracks does not match the trend for the 3D roughness, but the measurements taken along the sintered tracks and in the 45° degree inclined direction show trends similar to that of the 3D roughness values, though the slopes are different.
1.INTRODUCTION
Direct Metal Laser Sintering (DMLS) is gradually becoming a popular process for manufacturing of crucial functional parts, including customized biomedical implants. Researchers have studied the effect of DMLS parameters, namely laser power, scan speed and hatch spacing on the surface roughness of sintered surfaces, but most of the previous studies had used 2D roughness parameters to characterize the surfaces[1].
Fig. 1. DMLS Ti6Al4V surface with visible horizontal sintered tracks
Conventionally, in cases of surfaces with
directional marks, such as the machined surfaces the 2D surface roughness is measured across the 'lay' [2], and this also holds true for the DMLS surfaces[3]. But, as the sintered tracks on DMLS surfaces can be hundreds of micron in width, the roughness along the sintered tracks is also a significant component of the actual roughness of the surface. Therefore, in the
current study, 2D roughness of the DMLS surfaces have been compared with the 3D roughnessto assess the reliability of 2D measurements. 2. MATERIALS AND METHODS Ti6Al4V Direct Metal Laser Sintered samples of dimension 10mm X 10mm X 1mm were prepared in the DMLS machine EOSINT M 270 (EOS GmbH). The laser power, scan speed and scan spacing were varied from 120-195 watt, 800-1500 mm/sec and 0.06-0.12 mm, respectively. The 2D roughness along the sintered tracks, perpendicular to the tracks, and along a line inclined at 45° with the tracks were measuredusing a non-contact profiler (Tallysurf CCI Lite, Taylor Hobson). 3D roughness of the surfaces were also measured. 3. RESULTS AND DISCUSSION
2D average surface roughness, when plotted against line energy density, which is the measure of laser energy input per unit length of the sintered tracks, shows a downward trend for the readings taken along the sintered tracks and also for the readings taken at 45° to the sintered tracks, but no such trend can be seen for the readings taken across the tracks or the 3D average roughness.
4th National Conference on Advances in Metrology - AdMet2015 MAM-7
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Fig. 2. 3D profile of the sintered surface The slope of the fitted line for the readings taken along the sintered tracks is higher than the slope of the fitted line for the readings taken at 45°. But the 3D average roughness, when plotted against the laser energy density, which is the measure of average energy input per unit area of the sintered surface, again a downward trend can be seen. The reduction in the roughness with increasing laser energy density is due to the reduced amount of partially molten powder particles and the increased flowability of the molten material.
4. CONCLUSIONS
This study shows that the 2D average roughness values, measured across the tracks, as the conventional practice suggests, does not match with the trends found from 3D roughness, making it an unreliable measure of roughness
REFERENCES 1.F. Calignano, D. Manfredi, E. P. Ambrosio, L. Iuliano and P. Fino, “Influence of Process Parameters on Surface Roughnessof Aluminum Parts Produced by DMLS”, International Journal of Advanced Manufacturing Technology,67(2013), pp2743–2751 2. Anna Zawada-Tomkiewicz, “Estimation of surface roughness parameter based on machinedsurface image”, Metrology and Measurement Systems, XVII (2010), pp.493-504 3. Nora M. Huang., “Analyzing the Surface Finish of Knee Implants to Determine Criteria for Applications in Direct Metal Laser Sintering”, Proceedings of The National Conference On Undergraduate Research (NCUR) 2012.
4th National Conference on Advances in Metrology - AdMet2015 MAM-8
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Measurement analysis in Electrochemical Discharge Machining (ECDM)
Process
Pravin Pawar1, Raj Ballav2, Amaresh Kumar3 1Ph.D Scholar, Department of Manufacturing Engineering, NIT Jamshedpur.
2Associate Professor, Department of Manufacturing Engineering, NIT Jamshedpur. 3Associate Professor, Department of Manufacturing Engineering, NIT Jamshedpur.
E-mail: [email protected]
This research paper shows a brief study on various measuring instruments used for analysis
of various parameters of the electrochemical discharge machining process on various types of
materials, tool material, input & output parameters such as surface roughness, surface texture,
material removal, tool wear etc.
4th National Conference on Advances in Metrology - AdMet2015 MAM-9
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Optimization of High Speed End Milling Process (HSEM) in OFHC
Copper based on Surface Roughness and Cutting Force
Sankar Karmakar, M. K. Biswal, S. Y. Pujar, Praveen Kumar, Nitish Kumar Manufacturing Technology Group, CSIR- CMERI, Durgapur-713209, India
E-mail: [email protected]
This study was conducted to investigate the effects of cutting parameters on surface
roughness and force in high speed milling using ball end mill cutter in OFHC Copper
material. In process of Experimentation priority has been given for process parameter
optimization based on metrological results and it’s desired requirements. Process parameters
like feed rate, axial depth of cut and cutting velocity were considered for multi response
optimization.
Robust Design of Experiment were considered using L9 orthogonal array followed by
Grey Relational Analysis (GRA). The experimental results show that cutting speed and the
feed have the highest and lowest impact on the response parameters respectively. In this work
we demonstrate the possibility of high speed milling using end mill (ball nose) cutters. The
experiment used to predict the best possible combination of cutting parameters to achieve
desired surface finish with the minimum application of cutting forces. Hence the findings will
be reference support for high speed milling to produce fine surface finish through ball end
milling with minimum resources
Keywords: High speed milling, OFHC copper, surface roughness, cutting forces, Grey
relational analysis
PS-V Quality Assurance (QA)
4th National Conference on Advances in Metrology - AdMet2015 QA-1
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Understanding ISO/IEC 17025:2005 and Calibration & Measurement
Capabilities in Mass Measurements
Tripurari Lal
Ex Scientist G & Head Mass Standards
National Physical Laboratory, New Delhi-110012
E-mail: [email protected]
The International Standard ISO/IEC 17025 is one of the most importance components of the
infrastructure of a country necessary to overcome the Technical Trade Barrier of the World
Trade Organization in order to globalize its trade and to exploit its competitive advantages of
indigenous raw materials and low labor costs. The importance of this standard in, capacity
building of a country, conformity assessment, and principles behind it, have been
summarized in this paper. Based on these principles, the concepts of CMCs for the parameter
of mass measurements have been also highlighted.
4th National Conference on Advances in Metrology - AdMet2015 QA-2
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Guidelines for Standardization of Lightweight Wall Design and Installation
for the Acoustical Performance in Buildings
Mahavir Singh
Acoustics, Ultrasonics & Vibration (AUV) Section, Apex Level Standards & Industrial Metrology
Division, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012
E-mail: [email protected]
Guidelines are presented for the design and proper installation of high-performance,
lightweight partitions in residential and commercial buildings that meet desired acoustical
ratings. Typical wall and floor/ceiling systems with associated STC ratings are presented.
Good construction practices to minimize flanking paths and maximize in-field performance
are covered as well.
4th National Conference on Advances in Metrology - AdMet2015 QA-3
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Intermediate Checks Enhances Confidence on Calibration Intervals
K. Arulselvi and K. Sankara Subramanian
Electronics Test & Development centre
Department of Electronics & Information Technology
Thiruvanmiyur, Chennai 600 041
E-mail : [email protected]
The calibration interval is defined as the period of time between successive, scheduled
calibration of M & TE. Measurement reliability is the probability of in-tolerance condition of
the M & TE at a given time within the interval. Measurement reliability decreases with time
since calibration. Many Electrical and Electronics M &T E parameter values due to stresses
like environmental stresses and diversity of usage tend to vary randomly. Apart from
external applied stresses some precision M & TE also exhibit shifts in parameter values
arising from inherent random processes and out-of-tolerances occur as random events. To
hold the measurement uncertainty to within acceptable limits and to prevent the use of out-
of-tolerance M&TE, intermediate checks on M &TE shall be carried out. Also it is the
requirement of ISO/IEC 17025 standard, that intermediate check shall be carried out to get
the confidence in the calibration status. Systematic and scheduled intermediate checks will
improve the confidence of the user and ensure that the values of the parameter of M&TE are
within the acceptable limits.
4th National Conference on Advances in Metrology - AdMet2015 QA-4
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Role of Inter-Laboratory Comparison in Laboratory Competence
Goutam Basu Scientist “F”, ERTL(E)
Inter Laboratory Comparison has been treated as a process of benchmarking the performance
of one laboratory with respect to a better one. With passage of time, Inter Laboratory
Comparison has come out as an excellent tool for monitoring quality of testing & calibration
of a laboratory & has become a vital tool towards monitoring the laboratory competence. The
process of inter-laboratory comparison is looked into with great details by the accreditation
body during demonstration of competence by a laboratory as an essential demonstration
parameter for Laboratory Competence. However, at times, the laboratories get a bit perplexed
in selecting the participating laboratories for Inter-Laboratory Comparison & get puzzled
whenever some frustrating results are received. In this paper, an attempt has been made
towards appropriate conduction of Inter Laboratory Comparison for assuring quality of
testing & calibration, keeping in view the real life situations..
4th National Conference on Advances in Metrology - AdMet2015 QA-5
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Best Practices for Calibration and Maintenance of Laboratory Equipment
at RDCIS, SAIL, Ranchi
K. K. Toppo, Shree Prakash, H. N. Das, R. K. Jha, K. K. Mallik Research and Development Centre for Iron and Steel, Steel Authority of India Ltd.
E-mail: [email protected], [email protected]
RDCIS is equipped with more than 300 sophisticated laboratory equipment/pilot facilities for
testing, research and process simulation. These facilities are being extensively used for
undertaking R&D projects in SAIL plants for process developments as well as producing new
value added products. The technological recommendations that can be evolved by the use of
the aforesaid equipment are largely dependent upon the reliability and authenticity of the
output parameters. It is therefore, needless to emphasise the importance of maintenance and
calibration of these equipment and facilities. This paper deals with the best practices used for
achieving the above aim and objectives.
4th National Conference on Advances in Metrology - AdMet2015 QA-6
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Quality Assurance of Gauge Block Comparison Calibration at CSIR-NPL,
India for the Implementation of ISO17025:2005 Technical Requirement 5.9
Jokhan Ram, M. Arif Sanjid, Vinod Kumar, K. P. Chaudhary Standards of Dimension, CSIR- National Physical Laboratory,
Dr K S Krishnan Marg, New Delhi – 110012
E-mail: [email protected]
The quality assurance of calibration /testing is most important requirement of ISO
17025:2005. This technical requirement 5.9 is stated in ISO 17025: 2005 as follows. The
laboratory shall have quality control procedures for monitoring the validity of tests and
calibrations undertaken. The resulting data shall be recorded in such a way that trends are
detectable and, where practicable, statistical techniques shall be applied to the reviewing of
the results. This monitoring shall be planned and reviewed and may include, but not be
limited to, the following:
1. regular use of certified reference materials and/or internal quality control using
secondary reference materials;
2. participation in inter-laboratory comparison or proficiency-testing programmes;
3. replicate tests or calibrations using the same or different methods;
4. retesting or recalibration of retained items;
5. Correlation of results for different characteristics of an item.
And the clause also suggests quality control data shall be analysed and, where they
are found to be outside pre-defined criteria, planned action shall be taken to correct the
problem and to prevent incorrect results from being reported.
At NPL-India the requirements are fulfilled in three stages. First, we establish
measurement setup for the calibration gauge block calibration by comparison method. At this
stage the traceability of measurement is ensured. Then measurement procedure and
uncertainty of measurement are validated. Secondly, we have devised methods to ensure the
quality of measurement through inter laboratory comparisons, replication and recalibration.
We apply cross checking of results in three stages. And we also analyse them statistically.
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In the entire process, we record discrepancies, deviations and correction to prevent
incorrect results. Then the necessary actions will be implemented as per the pre defined
criteria – schedule. In this paper, the calibration procedure is explained with examples and
case-study. The best practiced gauge block comparison and measurement uncertainty are
given.
Keywords: gauge block comparison, 17025:2005, uncertainty of measurement, quality
assurance
ISO 10012:2003(E) - MEASUREMENT MANAGEMENT SYSTEM& METROLOGICAL
CONFIRMATION
by: Sanjib Kumar Nag,PralaySingha, Dwaipayan Samanta&Anirban Das
Young Engg& Calibration Services Pvt Ltd.
Abstract: Operation of Testing & Calibration Laboratories are based on Measurement Science. An effective Measurement
Management System ensures that measuring equipment& measurement processes are fit for their intended use. This is also
important in achieving product quality objectives & managing the risks of incorrect measurement The methods used for the
measurement management system ranges from basic equipment verification to the application of statistical techniques in the
measurement process control.
Introduction:
ISO 9001:2008 standards focuses on a business process model that includes all parts of the organization.
Requirements and other inputs are acted on by a process to produce an output, and improvement is by various
feedback processes such as management responsibility and corrective/preventive action. The big process (the
business as a whole) is a network of other processes, each of which contribute in some manner to the quality of the
product. One of those processes is the measurement management system.
In ISO10012:2003, the term "Measurement Process" stands for all physical measurement activities, like formation
of the process, data collection, analysis and even inspection of the process & equipment.
This international standard may be referred to by:
1) A customer, when specifying their requirements.
2) A supplier when specifying their product offered.
3) Regulatory Bodies
4) Assessors during audit of Measurement Management System.
About ISO 10012:
The ISO 10012:2003 is a requirement standard and also guideline type standard. If we read the introduction of the
standard we can find this:
“This International standard includes both requirements and guidance...”
And also this:
“Except by agreement this International Standard is not intended to add to, subtract from, or replace any
requirements of other standards”
It is important to know what the standard is not:
ISO 10012 is not a stand-alone requirements standard. It is a supplement to ISO 9001:2008. It is there for
you and the auditors to use, but an organization cannot be audited to 10012 by itself.
The standard is not a calibration process standard. Calibration is mentioned, but as only one of many parts
of the metrological confirmation process.
The standard is not a requirement for an in-house calibration system. Calibration can be obtained from
suppliers and managed just like any other purchase of services.
ISO 10012 does not tell you how to calibrate anything (nor do any of the other 12+ standards in the ISO 9000
family). It does not have any calibration procedures. It does require calibration as part of the metrological
confirmation process, as calibration is the part that provides traceability to the SI and part of the information about
measurement process uncertainty. Calibration (performance verification) procedures may be obtained from the
equipment manufacturer, other industry or government sources, defined standards from organizations such as ISO,
IS, BS, OIML, DKD, ASTM or ASME, or developed by a metrology engineer.
ISO 10012 does not tell you what specific equipment needs to be calibrated. You have to derive that information
from the requirements of the product, customer and other interested parties.
With regard to software, there are a couple of important things. If the software is used only for keeping records, then
the organization only has to show that it meets requirements – that’s ordinary rest and evaluation of the software
after purchase and installation. If the software is used to make measurement or operate measurement instruments,
then it must also be validated. That is, you must be able to demonstrate that the correct operations are done, the
mathematical calculations are based on valid algorithms and are performed correctly, the results are interpreted
correctly, and the correct data is stored. The classical method of validation is to compare automated results to
manual measurement results, but that is not always appropriate or even possible with sophisticated systems.
Specified metrological requirements are derived from requirements for output product. For testing & calibration
laboratories these are test reports & calibration certificates, which are totally dependent on measurement processes
and equipment used. Requirements may be defined as: Max. Permissible error, Permissible Uncertainty, Range of
measurement, Stability of the total process, resolution of the equipment, environmental conditions & Operator's
skill.
ISO 10012 has the following requirements:
1. Management requirement:
a) Metrological Function
b) Customer Focus
c) Quality Objectives
d) Management Review
2. Resource Management:
a) Human Resources
b) Information Resources
c) Material Resources
d) Outside Supplier
3. Metrological Confirmation & realization of Process
a) Metrological Confirmation
b) Measurement Processes
c) Measurement Uncertainty& Traceability
4. Measurement Management System analysis & improvement
a) Auditing & Monitoring
b) Control of Nonconformities
c) Improvement
5. Overview of Metrological confirmation Process
a) Customer's metrological requirement
b) Measuring Equipment characteristic
c) Verification & Metrological confirmation.
Calibration:
The International Vocabulary of Metrology (VIM 2.39) defines the term Calibration as an “operation that, under
specified conditions, in a first step, establishes a relation between the quantity values with measurement
uncertainties provided by measurement standards and corresponding indications with associated measurement
uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result
from an indication.
A calibration may be expressed by a statement, calibration function, and calibration diagram and calibration curve or
calibration table. In some cases, it may consist of an additive or multiplicative correction of the indication with
associated measurement uncertainty.
Calibration should not be confused with adjustment of a measuring system, often mistakenly called “self-
calibration”, nor with verification of calibration
Difference between Calibration & Verification:
A calibration indicates the error of the instrument and compensates for any lack of trueness by applying a correction.
A verification indicates that the measurement error is smaller than a so called maximum permissible error. Users
define the maximum permissible error as the largest error that they are prepared to accept.
Metrological Confirmation:
According to ISO 10012, metrological confirmation is a set of operations required to ensure that measuring
equipment conforms to the requirements for its intended use.
Metrological confirmation generally includes calibration and verification, any necessary adjustment or repair, and
subsequent recalibration, comparison with the metrological requirements for the intended use of the equipment, as
well as any required sealing and labelling.
Metrological confirmation is not achieved until and unless the fitness of the measuring equipment for the intended
use has been demonstrated and documented.
The requirements for intended use include such considerations as range, resolution and maximum permissible errors.
Metrological requirements are usually distinct from, and are not specified in, product requirements.
Verification & Metrological Confirmation:
After the calibration, the MEMC are compared to the CMR before confirming the equipment for its intended use.
For example, the reported error of indication of the measuring equipment would be compared to the maximum
permissible error specified as a CMR. If the error is smaller than the maximum permissible error, then the
equipment complies with that requirement, and may be confirmed for use. If the error is greater, action should be
taken to remove the nonconformity or the customer should be informed that the equipment cannot be confirmed.
Such direct comparison of MEMC and CMR is often termed verification (see ISO 9000). The metrological
confirmation system is firmly based on such verifications, but should also include detailed consideration and review
of the complete measurement process in order to give assurance of the quality of the measurements made with the
equipment, in support of determining the compliance of a product with the customer requirements.
Whether performed by the user or by the metrological function, the results of the verification process may be
compiled into a verification document, in addition to any calibration or test certificates or reports, as part of an audit
trail within the metrological confirmation system. The final stage in the metrological confirmation system is the
proper identification of the status of the measuring equipment, for example by labelling, marking, etc. After this, the
measuring equipment may be used for the purpose it has been confirmed for.
Measuring equipment Metrological Characteristics
Since the MEMC are often determined by calibration (or several calibrations) and/or tests, the metrological function
within the metrological confirmation system specifies and controls all such necessary activities. The inputs for the
calibration process are the measuring equipment, a measurement standard, and a procedure stating the
environmental conditions. The calibration results should include a statement of the measurement uncertainty. This is
an important characteristic as an input when evaluating the measurement uncertainty for the measurement process
when the equipment is used. The calibration results may be documented within the metrological confirmation
system by any appropriate method, for example as calibration certificates or calibration reports (when calibrations
are outsourced), or by records of calibration results (when performed entirely within the metrological function of the
organization).
Flow diagram of the complete metrological confirmation process
CMR - Customer Metrological Requirements (3).
MEMC - Measuring Equipment Metrological Characteristic (5).
R&R – Repeatability &Reproductability (4)
PMAP - Process Measurement Assurance Program (8).
Conclusion: From the above context it may be inferred that ISO 10012:2003, may be used by any Laboratory/
Organisation who are running their Management System in accordance with ISO 9001/ ISO 17025 or ISO 15189,
towards Monitoring & Planning their day to day services.
References:
1. ISO 9001:2008, Quality management systems — Requirements
2. ISO 10012: 2003, Measurement Management System – Requirements for Measurement Processes and Measuring Equipment
3. ISO 9000:2005, Quality Management System, Fundamental & Vocabulary
4. ISO/IEC 17025:2005, General requirements for the competence of testing and calibration laboratories
5. JCGM 200:2012, International vocabulary of Metrology – Basic and General Concepts and Associated Terms (VIM)
PS-VI Uncertainty in
Measurements & Standards (UMS)
4th National Conference on Advances in Metrology - AdMet2015 UMS-1
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Establishment of Secondary Hardness Standardizing Machines at NPL
India
Rajesh Kumar* and Rakesh Khanna
Force & Hardness Standard
CSIR-NPL, New Delhi
*E-mail: [email protected]
Hardness testing plays an important role in materials testing, quality control and acceptance of
components in various production houses. It is basically the resistance of a material to
permanent plastic deformation, penetration, indentation, and scratching. Hardness testing is a
widely used form of materials test in industries normally done with the help of commercially
available hardness testers. It is relatively easy to perform and is completely non-destructive
test, done by loading an indenter of specified geometry onto the material for a specified length
of time and measuring either the depth of penetration or dimensions of the resulting
indentation or impression. Rockwell, Brinell and Vickers hardness scales are most commonly
used to categorize the materials in terms of hardness numbers. These hardness scales are
realized by different kind of hardness standardizing machines established at national
metrological institute like NPL India for maintaining and disseminating it to support the
Indian industries. Working in this direction, NPL I has recently established a second chain of
Rockwell, Brinell and Vickers hardness standardizing machines (Lever Type) in addition to
the primary dead weight Rockwell, Brinell and Vickers hardness standardizing machines to
complete the measurement traceability chain throughout the country for hardness scales by
way of calibrating the standardizing hardness blocks as per the standard calibration procedure
based on international standards ISO6508, 6, and 7 respectively.
In this paper the secondary Brinell hardness standardizing machine (lever type) is
being described and discussed for its validation results by indirect verification in comparison
to the recently procured UKAS certified MPA Hardness Blocks in the hardness range of 234
& 425 HBW in 2.5/187.5 and 50 and 100 HBW in 1/5 Hardness scales and concluded that in
every case the deviation value is found to be within the uncertainty limits of the machine,
hence machine performance is found to be well within the limits as prescribed in the Brinell
Hardness Standard ISO-6506-2005 part 3. The machine is thus suitable for calibration of the
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Standard hardness blocks. With the establishment of this facility, NPL is in a position to
provide national traceability in all hardness scales viz. Brinell, Vickers and Rockwell
hardness, to the NABL accredited laboratories and other ISO certified industries.
4th National Conference on Advances in Metrology - AdMet2015 UMS-2
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Comparative Estimates of Measurement Uncertainty by Two Calibration
Methods using Flame Atomic Absorption Spectroscopy
Daya Soni, Niranjan Singh, Shankar G Aggrawal and Prabhat K Gupta CSIR-National Physical Laboratory, New Delhi-110012
E-mail: [email protected]
A comparative study on the measurement uncertainty estimates has been done by analyzing
the content of iron (Fe) in high purity quartz using multipoint calibration and single point
calibration method to achieve uncertainty estimates by both methods. This can improve the
metrological capability at international level by providing the reasonable estimates of
measurement uncertainty. Measurement uncertainty is estimated as per EURACHEM/
CITAC Guide CG 4. The uncertainty associated with the determination of iron by flame
atomic absorption spectrometer (FAAS) using multipoint calibration method is found to be
93.14 ± 7.42 mg/kg and using single point calibration method is found to be 89.86 ± 2.48
mg/kg. The reported uncertainty is at coverage factor k = 2, which corresponds to a coverage
probability of approximately 95% for a normal distribution. The potential sources of
uncertainty in iron determination by FAAS taken into account are instrument response
(linearity of calibration curve), repeatability, calibration standard and balance. The
contribution due to instrument response is 3.80% which is reduced to 0.93% in single point
calibration method. Comparison of all the uncertainty parameters in both methods shows that
the major contributing factor in multipoint calibration method is the calibration curve which
is not needed in single point calibration method. Hence, it is found that instrument response
due to calibration curve is the major reason for higher uncertainty estimates.
4th National Conference on Advances in Metrology - AdMet2015 UMS-3
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Comparison Studies of Different Simple Shaped Precision Force
Transducers
Harish Kumar and Anil Kumar
CSIR – National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi, India
E-mail: [email protected]
Ring shaped force transducer force transducers have been widely used for different force
measurement related applications like verification of material testing machines, transfer
standard, weighing scales etc. Ring shaped force transducers are widely used for different
metrological applications and are equipped with dial gauge. The ring shaped force
transducers have now been strain gauged to provide improved metrological capabilities with
improved resolution. Some simple shaped modifications of ring shaped force transducers
have been presented recently as an alternative of ring shaped force transducers like hexagonal
ring, octagonal ring. The paper attempts to discuss brief discussion about such force
transducers like their constructional features, advantages and disadvantages. The paper
further presents a comparison of different simple shaped force transducers on the basis of
metrological considerations. The force transducers are metrologically investigated according
to standard calibration procedure and suitable factors are taken into account for the
computation of the uncertainty of measurement of force transducers. The paper concludes
that each of the shape presented has some its salient features and a significant variation is
observed in their metrological capabilities.
4th National Conference on Advances in Metrology - AdMet2015 UMS-4
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Uncertainty Estimation in Determination of Calcium by Flame Atomic
Absorption Spectrophotometer
Khem Singh, Daya Soni, Niranjan Singh, Nahar Singh, Shankar G. Aggarwal and Prabhat K. Gupta
Analytical Chemistry, National Physical Laboratory, New Delhi 110012, India Email: [email protected]
Abstract: Flame atomic absorption spectrometry (FAAS) technique has been used for the determination of calcium in drinking water as per ASTM D511-03. Addition of lanthanum is done during calcium determination in drinking water, to help complete atomization of calcium in the flame. Calcium standard solutions for FAAS calibration were prepared from NIST SRM 1643e by gravimetric dilution. Measurement uncertainty budget is calculated of desired concentrations by taking potential sources involved in the analysis as per EURACHEM/ CITAC Guide CG 4 as shown in figure below. The uncertainty associated with the determination of calcium is found to be 109.81 ± 6.01 mg/kg. The reported uncertainty is at coverage factor k = 2, which corresponds to a coverage probability of approximately 95% for a normal distribution. The potential sources of uncertainty in calcium determination by FAAS taken into account are Instrument response, linearity, repeatability, reproducibility, calibration standard, balance and dilution. The results show that the uncertainty calculations are important in understanding the critical parameters associated with the measurement.
1. INTRODUCTION
Calcium is an element that a human body needs for various functions, such as building and maintaining the bones and teeth, blood clotting, transmitting of the impulses and regulating heart’s rhythm. Calcium deficiency can increase the risk of bone disorders, such as osteoporosis (Lanou, 2005). However, FAAS is one of the most extensively used techniques for the determination of numerous elements with precession and accuracy. The aim of the study is to determine calcium in drinking water and to calculate the uncertainty associated with the measurement.
2. EXPERIMENTAL
FAAS (Analytikjena, Vario-6.0) is a spectro analytical procedure for the quantitative determination of chemical elements employing the absorption of optical radiation (light) by free atoms in the gaseous state. A Ca hallow cathode lamp was used as the radiation source. In the AAS method, light of the desired wavelength (for Ca, λ = 422.7 nm) is passed through the flame, which contains the atomized analyte. The amount of light absorbed by the analyte depends upon the concentration of analyte (based on Beer's law). A series of standard solutions is prepared in order to calibrate the response of the instrument. The flame composition was acetylene and air.
All samples and standards were prepared gravimetrically in 0.2% Lanthanum (La) in 1% HNO3 using Milli-Q water (>18.2MΩcm). Calcium
calibration standard solutions for AAS were prepared from 109.4412 mg/kg Ca standard (NIST SRM 3109a) by weight in the range of 0.4263, 0.8592, 1.4784 and 3.062 mg/kg, respectively. A pre-calibrated OHAUS electronic balance was used for weighing purpose. The balance calibration is traceable to Mass Standard, CSIR-National Physical Laboratory (NPLI), New Delhi, India. The entire sample and calibration standard were prepared in pre-treated polyethylene bottle. The high purity Lanthanum oxide (La2O3) was used in this study to avoid phosphate or other elemental interference.
3. SOURCES OF UNCERTAINTY
Measurement uncertainty is calculated taking potential sources involved in the analysis as per EURACHEM/ CITAC Guide CG 4 and sources of uncertainties are represented by figure 1.
Figure 1. Cause and effect diagram for depicting uncertainty components associated with the
measurement.
Instrumental measurement
Repeatability
Calibration Std(s)
Final Concentration
(mg/kg)
Instrumental calibration
Linearity
Instrument response
Calibration standard
Reproducibility
Standard
Balance
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4. RESULTS AND DISCUSSION
Flame atomic absorption spectrometry (FAAS) technique has been used for the determination of calcium in drinking water. To avoid the interference of phosphorous, freshly prepared 0.2% lanthanum in 1% HNO3 (ultra pure grade) is used. Calcium calibration standard solutions for AAS were prepared from 31.5±1.1 mg/kg Ca standard from NIST SRM 1643e by weight in the range of 0.5 to 3.0 mg/kg. First the standards were injected and as a result we get calibration graph (r2 = 0.98) (Fig. 2) and then samples were injected to FAAS. Along with the sample analysis blank sample were also done. The final concentration of the sample comes out to be 109.81 mg/kg and the uncertainty associated with the determination of calcium is found to be ±6.01 mg/kg. The reported uncertainty is at coverage factor k=2, which corresponds to a coverage probability of approximately 95% for a normal distribution. The results also show that the uncertainty calculations are very important in pinpointing the critical parameters associated with the measurement.
Fig. 2. Calibration graph for Ca by FAAS
REFERENCE
ASTM D511-03: Standard test methods for Calcium and Magnesium in Water.
Lanou, A. J., Berkow, S. E., & Barnard, N. D., Pediatrics, 115, 736 (2005).
4th National Conference on Advances in Metrology - AdMet2015 UMS-5
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Need of Calibration Facilities and Preparation of Reference Materials
for Breath Alcohol Analyzers
S. Swarupa Tripathy, Nahar Singh, Rajiv K. Saxena and Prabhat K. Gupta
CSIR-National Physical Laboratory, New Delhi
E-mail: [email protected]
Breath alcohol analyzer is used to enforce driving under the influence of alcohol legislation
and in the forensic laboratories. The accuracy and reliability of the routine measurement
result of alcohol content performed with breath alcohol analyzer can be achieved by the
calibration of the breath alcohol analyzer using SI traceable reference material (RM). This
gives a transparency in legal verification required in various sectors viz. road & safety,
airport authority, forensic laboratories etc. At present in India nobody is working in the
proposed field and the RMs are being procured from abroad for the calibration of breath
analyzers. Globally many NMIs are active to address in this important measurement issue,
which involve enforcement of legal systems. Several international key comparison programs
have been organized so far for the determination of ethanol content in aqueous and in
nitrogen/air. National Institute of Standards & Technology, USA and BAM, Germany has
developed some Reference Materials of ethanol in water solution/ air with different
concentration ranges. The importance of the issue is to provide national traceability by NPL,
being the NMI of India in the area of ethanol in water/air reference materials which can be
used for the verification and calibration of breath alcohol analyzer in the country to mitigate
this problem in future. This program has societal impact which contributes to human health
and regulatory needs in the country.
4th National Conference on Advances in Metrology - AdMet2015 UMS-6
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A Review on Analysis of Calibration Interval
Amal K Ghosh, C. R. Datta Netaji Subhash Engineering College, Techno City, Garia, Kolkata-700152, India.
E-mail: [email protected]
Assessment of calibration interval is the crucial issue to the users of instrument for
monitoring the quality in industrial processes and test and measuring laboratories. Calibration
of instrument is executed on the basis of performing periodic test. Proper calibration interval
is an important specification in any quality assurance programme. The interval of calibration
is mostly decided using the rule of thumb, typically one year, a fixed-interval calibration
process. However, we come across sensors, equipment and instruments having different
complexity and frequency of use. The need and cost of calibration might call for optimum
interval of calibration. In this paper we have discussed the various approaches in arriving at
the interval of calibration and made a qualitative assessment.
Keywords: Calibration Intervals, Manufacturers’ Recommendation, Specification,
Algorithm, Simple Response Method.
4th National Conference on Advances in Metrology - AdMet2015 UMS-7
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Quality System in Non- R&D Centre for Calibration & Testing at CSIR-
NPL, New Delhi
Manju Arora and V.K. Gumber CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi -110 012
E-mail: [email protected]
Non-R&D Centre for Calibration & testing (CFCT) was established in CSIR-NPL with a
view to act as an interface between the customer interested in calibration and testing job
from industry, government/public sector organizations from India and abroad as well as from
within NPL activities or from CSIR sister labs. CSIR-NPL has been designated as National
Metrology Institute for maintaining and upgrading physical constant standards from India by
the Government India. Every year this centre will attend more than 3500 enquiries from the
customers on telephone, through e-mail, by post or via personal visit and approximately 2500
calibration and testing jobs will be undertaken by different labs in NPL. For the optimal
management and smooth functioning of such a vast spectrum of customers with a meagre
staff, quality system is adopted in centre as per ISO/IEC 17025:2005standard as the quality
policy recommendations of CSIR-NPL, New Delhi.. We are maintaining documents and
records pertaining to soft and hard copies of the case files generated for the calibration and
testing jobs, financial and administrative reports. This centre act as backbone and earns
external cash flow for NPL through calibration and test jobs done by trained scientists and
technical staff of 33 Standard activities undertaking such jobs for different parameters.
PS-VII Dimensional Metrology
& Machine Vision
(DMMV)
4th National Conference on Advances in Metrology - AdMet2015 DMMV-1
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Development of Automated Vision Inspection System for Two Wheeler
Engine Crankshaft
R. Deepa, J.Pradyumna, S.Harsha, S.Usha
Central Manufacturing Technology Institute, Tumkur Road, Bangalore-560022
E-mail: [email protected]
This paper presents an automated vision based measurement system for two wheeler engine
crankshafts. The system is able to perform the measurements with an accuracy of within
±10µm. Two setups are arrived at for measuring the different parameters and the
measurement software is developed. The results from the vision system are compared with
readings from conventional measuring equipments and accuracies achieved are tabulated.
4th National Conference on Advances in Metrology - AdMet2015 DMMV-2
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Measurement of Surface Roughness using Non-Contact Vision based
Technique
Satwik Kulkarni, Abhinav Joshi and Dr. Arati Mulay
College Of Engineering Pune, Wellesley Road, Shivajinagar, Pune-411 005
E-mail: [email protected]
Surface roughness today is gaining significant importance in the manufacturing industry
aimed to achieve close dimensional tolerances in order to obtain the desired quality of
product. This roughness value can be measured by a conventional contact method using a
diamond-tipped profilometer that may result in tool wear. Moreover, this method is not
reliable when the discontinuities on the test surface are close to the stylus dimensions. This
paper demonstrates the measurement of surface roughness by a non-contact (vision based)
measuring equipment with embedded electronics and integrated software, which serves the
purpose of dimensional measurement as well as reverse engineering for various engineering
industries. Using this equipment, initially, a 3-D Point Cloud Data (PCD) is obtained by
performing a contour scan of the test surface. Furthermore, a programming module is
developed which with the help of this PCD calculates roughness value by finding the best fit
plane using the least square technique. The value obtained by this method is compared with
the conventional method value and the results are validated.
Keywords: Surface Roughness, Non-contact (vision based) measuring equipment, Reverse
engineering, 3-D Point Cloud Data (PCD), Contour scan, Least square technique.
4th National Conference on Advances in Metrology - AdMet2015 DMMV-3
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Vision Based Surgical Screw Inspection
S. Harsha, R. Deepa, V. Kavitha, S. Usha Central Manufacturing Technology Institute, Tumkur Road, Bangalore
Email: [email protected]
Surgical screws are manufactured using titanium alloy as they are meant to be present inside
the human body. Due to this very requirement of these components ending up inside the
human body, these screws are to be critically inspected for the dimensions post
manufacturing. These surgical screws are manufactured in various sizes and shapes. All
screws call for general feature inspection and few special features specific for few screws.
Quality control in industrial manufacturing can be reliably performed with computer vision
systems that operate at high speed. Hence a vision based inspection system is evaluated for
inspecting the critical dimensions of surgical screws varying in sizes, shapes and features.
The vision based inspection system consists of a camera, suitable lighting and optics on the
hardware side and a computer with suitable software for analysis. Each screw is inspected by
the vision based inspection system for general features like head diameter, thread diameter,
head length and so on. The dimensional details of all the necessary features are obtained for
each screw in one go. The results obtained from the vision based inspection system are
compared with conventional measurement equipment in order to arrive at the accuracy of
inspection.
4th National Conference on Advances in Metrology - AdMet2015 DMMV-4
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Measurement of Diameter for Volumetric Standard Sphere with the High
Precision End Standard Gauge Blocks
Mukesh Kumar, Anil Kumar Standards Dimension
National Physical Laboratory India
E-mail: [email protected]
Accuracy for the Volume of sphere measurement always depend on the accuracy of the
diameter of the sphere The quantity always limits the value of uncertainty achieved. Higher
level of uncertainties is achieved by using Gauge block and Electronic Gauge Block
comparator for the measurement of the Diameter of spheres. At NPL we demonstrate a new
method of finding the diameter value by using the Electronic Gauge Block comparator
having LVDT(Linear Variable Differential Transformer)Probe with least count 0.01µm.
Highly precise Gauge blocks which are well calibrated by interferometric method with an
uncertainty of ±(0.03 +0.3L)µm where L value is in meter are used as a standard.
4th National Conference on Advances in Metrology - AdMet2015 DMMV-5
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Development of Ultrasonic Technique for Dimensional Accuracy and
Flatness of 1.2 mm Diameter Flat Bottom Holes
Yudhisther Kumar Yadav, Reeta Gupta, P K Dubey and *Gianinder Singh
CSIR-National Physical Laboratory New Delhi *Principal, Govt. College, Bhivani, Haryana
Email: [email protected]
In ultrasonic nondestructive testing and evaluation (NDT&E) of material it is easier to predict
the size of defect if the size is comparable to or more than the beam diameter of the ultrasonic
transducer. However, if the size of the defect to be detected is very small, it is very difficult to
estimate the size, for the standard 6 dB drop method or else. For this reason, the size of
smaller defects is estimated by using distance amplitude curves (DAC) or distance gain size
(DGS) methods. These methods require reference standards having flat bottom holes (FBH).
It is important as well as difficult to ascertain the dimensional accuracy and flatness of hole
bottom to obtain uniform ultrasonic response and better estimate of defect size. In the present
paper work has been done towards the solution of the problem and to develop a reliable
procedure for conformance to 1.2 mm flat bottom hole for different materials for its flatness,
perpendicularity to end surface and parallelism to curved surface. Measurements are made
using 5 MHz 10 mm diameter ultrasonic transducer and typical distance amplitude curves are
plotted for Al 7010 material blocks in immersion testing technique.
4th National Conference on Advances in Metrology - AdMet2015 DMMV-6
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Ultrasonic Study on Measurement of Surface Roughness of Reference
Cylindrical Blocks
Sandeep Kumar, Yudhisther Kumar Yadav and K. P. Chaudhary CSIR - National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi (India)
E-mail: [email protected]
Abstract: Ultrasonic is an innovative technology which is extremely eco friendly and finds many applications in different fields. Nowadays, it is replacing many established technologies due to its technical advantages. Some of the notable areas of ultrasonic technology are non destructive testing, imaging, Sonar, processing, cleaning, welding, weaponry systems etc. Surface topography is the study of qualitative and quantitative surface characteristics of components. It is important to determine the texture of components in order to achieve the desired properties and functional performance. At CSIR-NPL, a study has been carried out to find out the impact of surface on the echo amplitude of ultrasonic waves, when it is fired upon material blocks with different level of surface topography. Variation of echo amplitude of ultrasonic waves with varying roughness of the reference cylindrical blocks is studied using 20 MHz, 10mm diameter broad band ultrasonic transducer. Results of the study are discussed in details in full paper.
1. Introduction: Surface topography is an important aspect of manufacturing and affects quality and performance of finished goods. It is measured in terms of form, texture and flaws. Texture errors are the fine irregularities produced on the surface by the manufacturing processes. When ultrasonic waves are fired upon the surface of irregularities with different level, the resulting ultrasonic echo varies and affirms the topography of the surface. In this study, reference cylindrical blocks of same material with different roughness and flatness are probed with ultrasonic using pulse echo immersion method and echo amplitude is measured. Results are discussed in full paper. 2. Definition and Measurement Techniques: Surface texture refers to the fine irregularities (peaks and valleys) produced on the surface by the manufacturing processes. However often these are controlled by abrasive processes such as grinding, polishing, honing, lapping etc. Surface texture is very complex in nature owing to many finishing processes. ISO 4287:1997 has specified the parameters such as Rp, Rv,
Fig. 1: Graphically represented roughness parameters
4th National Conference on Advances in Metrology - AdMet2015 DMMV-6
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Rz, Rc, Rt, Ra, Rq, Rsk, Rku, RSm, R∆q, Rmr©, Rδc, Rmr. The most widely used statistical parameters of surface heights are the average roughness Ra and the root mean square r.m.s also known as Rq. Some roughness parameters are graphically shown in figure 1. Ra is evaluated by formula given below:
0
(1/ ) | ( ) | .l
Ra L y x dx= ∫
Rq often known as σ in optics community is evaluated by formula given below:
2 1/ 2
1((1/ ) | |) .
N
iN yiσ
=
= ∑
At CSIR-NPL, Mahr Perthometer S6P is being used for roughness measurement which is stylus type. The instrument is shown in figure 2.
3. Material and Method: Reference cylindrical blocks of same material with different roughness and flatness were probed for the study. Dimensional Study: Material block with different level of surface finish were obtained and used after grinding for the study. Their flatness and surface roughness was measured before the ultrasonic study. Ultrasonic Study: The sample blocks used in the dimensional method are used to measure the echo amplitude of the surface under study by using pulse echo technique with a 20 MHz 10 mm diameter ultrasonic broad band transducer. Ultrasonic Flaw Detector (Epoch 1000) is used
for excitation of ultrasonic transducer and for receiving the reflected signal in immersion testing at fixed sound path in water. The variation in reflected echo amplitude from the surface under study is compared with the known surface roughness of the block. The results can give prediction for the comparable surface roughness of the same material blocks. 4. Results and discussion: Thus a calibration graph for the echo height and surface roughness of the bock material is obtained. The dimensional method for measuring the surface roughness or flatness is tedious and time consuming. The ultrasonic calibration curves can be used to measure and evaluate the roughness of the same material. This type of information is helpful in evaluation of acceptable surface roughness and flatness of the cylindrical reference blocks used for sizing the defect in ultrasonic nondestructive testing techniques. 5. References: 1. ISO 3274:1998 Geometrical Product
Specifications (GPS) – Surface Texture: Profile Method – Nominal Characteristics of Contact (Stylus) Instruments (IS 15261:2002)
2. ISO 4287:1997 Geometrical Product Specifications (GPS) - Surface Texture: Profile Method – Terms, Definitions and Surface Texture Parameters (IS 15262:2002)
3. R. P. Singhal, “ Evaluation of surface roughness: A review’’, AdMet, 260-261, February 2013
4. Whitehouse D J “Handbook of Surface Nanometrology” Institute of Physics Publishing Bristol and Philadelphia, 2003.
5. R. E. Reason “The Trend of Surface Measurement” Ind.,Prod., Engrs. JI may 1954
Fig. 2: Mahr Perthometer S6P
4th National Conference on Advances in Metrology - AdMet2015 DMMV-7
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Remote Measurements using Image Analysis System
N. J. Padte1, R. V. Tambad2, Dr. J. C. Padte3
1 Director, JANGS Technologies, Ichalkaranji 2 Senior Engineer, Fie Research Institute, Ichalkaranji
3 Director, Fie Research Institute, Ichalkaranji
The paper highlights dynamic measurements using online image capturing techniques in
remote areas, with faster and smart indigenous algorithm. The optical system used here is
specially designed lens and light source arrangement for better clarity of the image. In such
measurements the resolution of analog measurement system can be amplified by interpolation
within graduation marks. The added advantage of such system in analog measurement is that
the parallax error is automatically eliminated. The data collection during the measurement is
automatic which can be used for further report generation. This system is ideally suited to the
task of non contact / non intrusive displacement measurement in a remote system. The
objective of this work in progress is to develop a compact instrument for displacement
measurement consisting of image capturing, analysis software, optics and the measurand as
an analog dial gauge.
4th National Conference on Advances in Metrology - AdMet2015 DMMV-8
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Image Texture Analysis using GLCM Technique for Evaluation of
Fractographs
1Samik Dutta, 2Himadri Roy and 3Ranjan Sen 1Scientist, PE&M Group, CSIR-CMERI Durgapur, 2Scientist, NDT & Metallurgy Group, CSIR-
CMERI Durgapur, 3Chief Scientist, PE&M Group, CSIR-CMERI Durgapur
Email: [email protected]
In order to select materials for specific applications and assessment of their performance in
service, it is imperative that materials be evaluated for their properties and functionality. A
number of procedures for evaluation of fractographs are available to material scientists. Most
procedures generally involve examinations at high magnifications using electron
microscopes. Image based texture analysis can be a quantitative tool for evaluation of
fractographs. Texture analysis method incorporating grey level co-occurrence matrix
technique has been carried out to characterize fractographs of AISI 304LN steel generated
from tensile tests at cryogenic conditions. A series of tensile tests are carried out from 100ºC
to -500ºC, thereby, generating different fractographic features, which is again found to
depend on the formation of deformation induced martensite. The results obtained from this
investigation reveal that there is a systematic correlation between mechanical vis-à-vis image
texture properties under cryogenic conditions for the selected grade of steel.
4th National Conference on Advances in Metrology - AdMet2015 DMMV-9
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Validation of Software used for Angle Gauge Block Calibration at CSIR-
NPL, India
M. Arif Sanjid, K. P. Chaudhary Standards of Dimension, CSIR- National Physical Laboratory,
Dr K S Krishnan Marg, New Delhi – 110012
E-mail: [email protected]
An angle block (AG) is hardened steel block having its two lapped working faces (measuring
faces) inclined at a nominal angle. In the field of dimensional metrology, direct comparison
method is used invariantly for the calibration of angle blocks. A Precision indexing table and
an autocollimator are sufficient to perform such calibrations. These instruments are
periodically compared against primary reference standard to determine their corrections.
These corrections are used in direct comparison calibration. Using this method, we can
achieve angle block measurement uncertainty approximately ±0.4”.
The calculations of these calibrations are carried out manually where the indexing
table is not automated. The calculations need sincere involvement to be unambiguous. At
NPL-India, we have developed software entitled “Angle gauge calibration” to aid
calculations. This software calculates the angular deviation of angle gauge block by narrating
each step of calculation. The angle block software is validated empirically as well as using
pen and pencil.
In present paper, we have described the algorithm of software along with basic
principal of calculations. A direct empirical mathematical equation was discussed. The
applicability of the empirical formula is also demonstrated.
PS-VIII Pressure, Temperature,
Humidity & Density (PTHD)
4th National Conference on Advances in Metrology - AdMet2015 PTHD-1
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A Large Diameter Piston Gauge as a Pneumatic Primary Pressure
Standard
Jasveer Singh, Ashok Kumar, Nita Dilawar Sharma* and A.K. Bandyopadhyay Pressure Standards, CSIR- National Physical Laboratory,
Dr. K.S. Krishnan Marg, New Delhi – 110 012
*E-mail: [email protected]
The pneumatic pressure laboratory of CSIR- National Physical Laboratory, India (CSIR-
NPLI) intends to establish a large diameter piston gauge (LDPG) with automated mass
loading and software control, as its pneumatic primary standard and strengthen our
traceability. Currently all our secondary standards are traceable to Ultrasonic Interferometer
Manometer (UIM) and with this new LDPG our traceability will be strengthened further.
These piston gauges can be used as primary pressure standards owing to their large diameter
which can be directly traceable to length standards. Due to this large diameter, a very
accurate dimensional measurement is possible for the piston and the cylinder, which gives
low uncertainties in effective area. This piston gauge is procured from DHI, USA (shown in
figure 1), and has two sets of piston-cylinder (p-c) units of 11 mm & 35 mm diameter pistons
designated as NPLI-P1 (1MPa) & NPLI-P10 (10MPa) respectively. A summary of properties
is tabulated in table 1. Both the pistons were initially calibrated by NIST, USA and the mass
set was calibrated by NRC Canada. The expanded uncertainty in effective area given by
NIST is 13x10-6 and 26x10-6 at k=2 for NPLI-P1 and NPLI-P10 respectively. Further NPLI-
P1 was cross floated with our reference standard NPLI-4 which is Ruska 2465. NPLI-4 is
directly traceable to our UIM. Excellent agreement of 1.8 ppm was achieved in these results,
which further strengthens our traceability for the zero pressure effective area. The results
would be discussed in detail.
4th National Conference on Advances in Metrology - AdMet2015 PTHD-1
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Figure 1
Table1
Parameter NPLI-P1 NPLI-P10
Nominal diameter 35 mm 11 mm
Material Tungsten Carbide Tungsten Carbide
Linear Thermal expansion
coefficient of P-C 4.5 x 10-6 /0C 4.5 x 10-6 /0C
Maximum Pressure 1 MPa 10 MPa
Expanded Uncertainty (in
effective area at k=2), NIST
USA
13 x 10-6 26 x 10-6
Key words: Large diameter piston gauge, Primary standard, Uncertainty evaluation
References
1. J W Schmidt, K. Jain, A P Miller, W J Bowers and D A Olson, Metrologia 43 (2006), pp 53-59.
2. NIST report of calibration, P-8796B, P-8796B (2009).
3. Dadson R S, Lewis S L and Peggs G N 1982 The Pressure Balance—Theory and Practice
(London: Her Majesty’s Stationery Office)
4th National Conference on Advances in Metrology - AdMet2015 PTHD-2
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An Over View of Humidity Standard at CSIR-NPL (India)
Bhikham Singh, Gaurav Gupta, D.D. Shivagan and Y.P. Singh Temperature and Humidity Standards
National Physical Laboratory, New Delhi – 110 012
E-mail: [email protected]
The research activity on the development of humidity sensors are increasing with the
increasing awareness/ demand of humidity measurement and its control. These sensors,
however, need to be calibrated periodically in known environment and have great advantages
of their electrical output. Thus the establishment of humidity sensor is very much in demand
by makers and users of humidity sensors (hygrometers). The measurement of relative
humidity plays an important role in industries including many areas such as Pharmaceutical,
Textile. Food, Tobacco, Semiconductor, Aerospace, Power generation and Environmental
testing etc. This paper reports various techniques of establishing Humidity Standards,
including Primary, Secondary, and Practical Methods, currently being used in International
Standards Laboratories like NIST USA; NPL UK; NMI Japan; PTB Germany; INTA Spain.
The establishment of Two Pressure Humidity Generator as Reference Humidity Standard
(Practical Method Humidity Standard) at CSIR-NPL, (India) has been described. In this
present setup the relative humidity (RH) is determined by measuring the chamber pressure
and saturated pressure (Pc/Psx100) with help of two precise pressure sensors. This humidity
generator is a self contained system capable of producing atmospheres of known humidities
using the fundamental “two pressure” principle. The humidity generation in the range of 10
% RH to 95% RH with an expanded uncertainty of ± 0.5 % RH (k=2). This system is capable
of continuously supplying accurately known humidity values for hygrometer/ instrument
calibration, evaluation and verification, as well as for environmental testing. The relative
humidity are calculated from the accurate measurement of precise pressure and temperature.
The traceability of pressure sensors and temperature sensors are against the Vacuum &
Pressure Standards and Temperature Standards of the NPL (India). To generate a known
humidity, the computer controls the pressure ratio Pc/Ps by utilizing the enhance factor ratio
Fs/Fc and Effective degree of saturation Es/Ec, humidity produced solely dependent on the
measurement of pressure and temperature. Precise humidity generation is determined by the
4th National Conference on Advances in Metrology - AdMet2015 PTHD-2
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accuracy and uniformity of temperature throughout the generating system. The RH generator,
which utilizes a source of nitrogen or air. The two pressure 2P (and single temperature)
humidity generator operating on a two pressure principle saturates gas at a high pressure. The
saturated gas is (isothermally) brought to a lower pressure (usually atmospheric pressure) via
an expansion valve. The ratio of two absolute pressures and the temperature of test chamber
provide the desired relative humidity or dew-point. The key measurements are of saturation
temperature, pressure and pressure at the generator outlet or chamber. The system have been
thoroughly tested and found suitable to be used as the reference humidity standard (Practical
Humidity Standard).
Keywords: Two pressure technique, Hygrometer, Relative Humidity, Saturation Pressure,
Chamber Pressure, Calibration Uncertainty, Reference Standard Humidity Generator
4th National Conference on Advances in Metrology - AdMet2015 PTHD-3
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Calibration of Density Hydrometer by Comparison Method at CSIR-NPL
M. B. Das, Anil Kumar and Surender Singh Yadav
CSIR - National Physical Laboratory, New Delhi – 110 012, India
E-mail : [email protected]
The calibration of density hydrometer is being important for the benefit of the economy and
society as a whole, improving commercial efficiency and quality of everyday life. To
maintain quality of various liquids the hydrometer calibration is an important metrological
measurement activity. Hydrometers may be classified according to the indication provided
by graduations of the scale as follows: (1) density hydrometers, to indicate densities at a
particular temperature, and usually for a particular liquid; (2) specific gravity hydrometers to
indicate specific gravity of a liquid, with reference to water, at a particular temperature; (3)
percentage hydrometers to indicate, at a particular temperature, the percentage of a substance
such as salt, sugar (Brix), or alcoholometer indicates alcohol dissolved in water; (4) arbitrary
scale hydrometers, indicating the density, specific gravity, or concentration of a liquid in
terms of an arbitrarily defined scale, at a defined temperature and lactometer is used to check
purity of milk.
Hydrometer can be calibrated by two methods:
1) The periodic multipoint scale calibration was done by well known primary method
(Cuckow’s method)
2) Commercial hydrometers are calibrated by direct comparison method , this method is
the simplest way to calibrate hydrometers using as different reference liquid with
known density.
Hydrometer may indicate different values over a period of time and it will require
recalibration. Changes also occur in the hydrometers scale, but they are usally too small to
be of concern and would be most noticeable in hydrometers. In this study L- 50 series
hydrometers have been taken into account due to vast used by several organization.
Keywords : hydrometer, calibration, comparison method
4th National Conference on Advances in Metrology - AdMet2015 PTHD-4
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Need of Automation for Pressure Calibration in Metrology Laboratory
Jnanabrata Chattopadhyay
Scientist “D”, ERTL(E)
Pressure Calibration has become a major Metrological activity in the area of Mechanical
discipline. However, this requires precise & accurate measurements by technically qualified
persons, which is a time consuming activity. The professional laboratories are constantly
pressurized with very high workload, but cannot afford to compromise with the quality of
work. The possibility of error always increases, if testing & calibration work is solely
manual. As such, the need for Automation in calibration of “Pressure” parameter is strongly
felt. The present paper aims at automating the process of Pressure Calibration in Metrological
laboratories & generating automated reports. It is expected that the automated Calibration
Techniques will lead to improved return on investment as also better quality & less errors in
Pressure Calibration.
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Assessment of Pt/Au Thermocouple on ITS-90 Fixed Points
from TPW (0.010oC) to Ag (961.78oC)
Hansraj Meena, Yetendra, R. B. Sibal, D. D. Shivagan and Y.P. Singh
Temperature & Humidity Standards, CSIR-National Physical Laboratory,
Dr. K. S. Krishnan Marg, New Delhi 110 012.
E-mail : [email protected]
The thermoelectric characteristics of noble metal thermocouples, such as Pt/Au, Pt/Pd and
Pd/Au, have been thoroughly being investigated because they offer advantageous of
compositional homogeneity and thermoelectric stability. The presently used industrial grade
thermocouples such as Type-S, Type-R and Type-B has one Pt wire alloyed with Rh, and has
a in-homogeneity and preferential degradation problem over the prolonged use. The former,
Pt/Au TC has better thermoelectric properties than Type-S TC below 1000oC. The Pt/Au is
the most accurate thermocouple available over the range 0 °C to 1000 °C, with an expanded
uncertainty (k=2) less than 8.3m°C from 0°C to 962°C, and rising to 14m°C at 1000°C, as
measured by NIST USA, and it can be used as a reference thermometer over high
temperature standard platinum resistance thermometer (HTSPRT) below 1000oC. Therefore,
in the present investigation, the assessment of Pt/Au TC was performed on ITS-90 defined
fixed points from 0.01oC to 961.78oC.
The Pt/Au thermocouple was specially-constructed using high purity gold and
platinum thermocouple wires, and then it was annealed at 1000oC. The cold junction is 20 cm
long along with integral lead wires and a protective quartz glass sheath. It was measured on
the fixed points from Ag (961.78oC), Al (660.323oC), Zn (419.527oC), Sn (231.928oC) and
TPW (0.010oC). The measurement plateau of each fixed point was recorded with online data
acquisition system made on LabVIEW platform. The melting-freezing plateau of F.P. of Ag
measured by Pt/Au TC is shown in Fig. 1. The various parameters contributing to the
uncertainty were evaluated in details and presented in this paper.
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0 50 100 150 200 250 30016000
16050
16100
16150
16200
16250
16300
16350
16400
EMF
(µV)
Time (Min.)
Realization of Pt/Au TC for Ag fixed point 961.78 oC
melting
Complete melt
Complete freeze
Freezing plateau959.5 oC
959.5 oC
966.5 oC
Nucleation
Fig. 1. The melting-freezing plateau of F.P. of Ag measured by Pt/Au TC.
4th National Conference on Advances in Metrology - AdMet2015 PTHD-6
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Development of Cobalt-Carbon Eutectic Fixed Point for Contact Thermometry
D. D. Shivagan, Hansraj Meena and Y.P. Singh Temperature & Humidity Standards, CSIR-National Physical Laboratory,
Dr. K. S. Krishnan Marg, New Delhi 110 012.
E-mail: [email protected]
The metal-carbon eutectic fixed points are being developed by leading National Metrology
Institutes (NMIs) as secondary fixed points for traceability above 1000 oC to contact and
non-contact thermometry. On the present International Temperature Scale of 1990 (ITS-90),
after copper (1084.62 oC) there is no fixed point until Palladium (1554.8 oC) for the
calibration of thermocouples and the extrapolation in this temperature gap results into higher
dispersion and hence higher measurement uncertainties. The new novel metal-carbon
eutectics technology has the potential in reducing the uncertainties by introducing (1154°C),
Co-C (1324°C), Ni-C (1329°C) and Pd-C (1492°C) eutectic fixed points in this temperature
range of contact thermometry. We have been putting the in-house R&D efforts from last few
years in this area, and successfully developed the Co-C eutectic fixed point at CSIR-NPL and
participated in APMP Comparison. The Co-C fixed point was realized using the noble metal
thermocouples, such as, Type-S, Type-R and Pt/Pd thermocouple. The measurement profile
of Co-C eutectic fixed point (1324 oC) measured by Type-R thermocouple is shown in figure
1, with the expanded uncertainty of ± 0.2 oC. The emf of each plateau was estimated by
talking the double derivative of the third order polynomial fit. The experimental details on the
development of fixed point cell and details of the measurement uncertainties will be
presented in this paper.
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Fig. 1. The experimental set-up of Co-C eutectic fixed point and its realization using Type-R TC.
30 35 40 45 50 55 60 65 7014860
14880
14900
14920
14940
14960
14980
15000
15020
15040
14958.17 µV
R-TC_Ist Melting R-TC_IInd Melting R-TC_IIIrd Melting
EMF
(µV)
Time (Min.)
Co-C Eutectic = 1324 oC
Graphite Crucible Cell
2.3 wt % C in CobaltCo : C
50.0045 g : 1.1605 g
4th National Conference on Advances in Metrology - AdMet2015 PTHD-7
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Standardization of Capsule SPRT from T. P. of Hg to M. P. of Ga
Umesh Pant, Hansraj Meena, D. D. Shivagan and Y.P. Singh
Temperature & Humidity Standards, CSIR-National Physical Laboratory,
Dr. K. S. Krishnan Marg, New Delhi 110 012.
E-mail: [email protected]
Standard platinum resistance thermometer (SPRT) is the primary interpolation device for the
realization of defined temperature fixed points on International Temperature Scale of 1990
(ITS-90). Capsule type SPRTs (cSPRT) are widely used in cryogenics, calorimetry and other
low temperature applications (-260oC to 232oC) because of its miniature size and low stem-
conduction compared to the conventional SPRTs. In the present investigation, a platinum
sheathed 25.5Ω cSPRT (Tinsley, B144) was calibrated in the range from triple point of Hg,
triple point of water (TPW) and melting point of Ga, the ITS-90 subrange of -38.8344oC to
29.7646oC. All associated Type-A and Type-B uncertainty components were evaluated at
each fixed point and the maximum uncertainty was found to be ±0.64 moC. Boltzmann
Constant project require four such high precision cSPRTs.
4th National Conference on Advances in Metrology - AdMet2015 PTHD-8
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Loss of Water Pressure between Upstream and Downstream Line during
Water Flowmeter Testing
I.S. Taak and Chatar Singh
Fluid Flow Measurement Standards, CSIR-National Physical Laboratory
Dr. K.S. Krishnan Road, New Delhi-110012
E-mail: [email protected]
The measurement of pressure loss (∆P) is an essential part of flowmeter metering. The
measurement of pressure loss in the pipeline and the flow meter require that we make hole in
the pipeline at upstream and down stream. The upstream and downstream taping from the
meter to the pressure gauge shall be as per ISO 4064 and IS 6784. These holes will give us
the value of differential pressure (∆P pressure loss). The Burdon gauges and pressure
transducers are used to measure pressure loss across the meter. The test on the meter was
carried out as per the ISO 4064 standard. The flowmeter used to check the flow rate was
adjusted with the help of regulator valve and reference standard (Rotameter). The pressure
gauges were used to measure pressure loss and pressure tightness test. The water was
collected in pre-determined time in a pre-calibrated standard vessel used to measure the
accuracy of water meter. The permissible accuracy from Qmax to Qt both inclusive are within
± 2% and transitional flow rate (exclusive) to minimum inclusive is within ± 5%. The
pressure loss measurement was determined at Qmax and Qnom. The pressure loss test is carried
out with metering accuracy and the permissible values at Qmax and Qmin are 1 bar and 0.25 bar
respectively as per IS and ISO standards. In the present paper, the details of water meter
testing along with associated measurement uncertainty will be presented.
4th National Conference on Advances in Metrology - AdMet2015 PTHD-9
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Progress towards Development of a Hydraulic Dynamic Pressure
Calibration System
A. Zafer, A. Sanjid, R. K. Sharma, L. Kumar, V. K. Gupta and Sanjay Yadav National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi – 110012, India
E-mail: [email protected]
The accurate pressure measurement and its calibration, either in static or dynamic conditions,
are essentially required as a process parameter for the validation of measurements. The
pressure calibration in static conditions is performed day by day with utmost precision and
accuracy. However, for dynamic conditions, pressure calibration is a big and unavoidable
challenge. The important metrological applications of dynamic pressure calibration are in
aerospace applications, ballistic missiles, automobile industry, gun barrels or any controlled
explosive condition where sudden rise in pressure takes place. The need for dynamic pressure
arises because of the ever increasing demand from the users to test fast transient response of
the pressure transducers. Output of a pressure sensor is normally frequency dependent. Some
piezoelectric transducers even cannot be statically calibrated because of their lack of low
frequency response. For such transducers, the calibration is performed only in static
conditions and as a result we can only get sensitivity. If such transducers are calibrated in
dynamic conditions, we can also get natural frequency, rise time, damping ratio etc.
Fig. 1: A layout diagram of the experimental setup
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Presently, there is no established primary pressure standard developed for traceable dynamic
pressure measurements. The EURAMET, a regional body of BIPM has taken up this issue
and as a follow up started a project, the European Metrology Research Programme (EMRP)
project IND09, entitled. “Traceable Dynamic Measurement of Mechanical Quantity”, for
developing two primary standard systems based shock tube (NPL, UK and SP, Sweden) and
drop weight system (MIKES, Finland and PTB Germany). Recognizing the importance of the
emerging area of dynamic pressure measurements, NPL, India has also initiated work on the
development of an experimental setup (shown in Fig. 1) which can be used for generating and
calibrating the dynamic pressure sensors in the pressure range up to 200 MPa. In this
experiment, an aperiodic type of pressure generator is developed and used which works on
the principle of quick open device. The present paper describes the report on the progress
towards the efforts made in this direction. We have designed a quick open valve whose
manufacturing is under process. An amplifier for data acquisition has also been designed. A
dead weight tester has been incorporated for generating traceable pressure measurements in a
pressure reservoir before quick open valve. The experimental details and preliminary results
obtained are reported.
