EURAMET.L-K8 Technical Protocol - KCDB - BIPM

EURAMET L-K8 Surface roughness comparison

EURAMET PROJECT 1003 SIM L-K8

Measuring instructions

CONTENT

1 Introduction ........................................................................................................................... 3 2 Organization.......................................................................................................................... 4

2.1 Participants .................................................................................................................... 4 2.2 Time schedule................................................................................................................ 5 2.3 Transportation................................................................................................................ 5 2.4 Unpacking, Handling, Packing ....................................................................................... 6 2.5 Financial aspects, Insurance ......................................................................................... 6

3 Standards.............................................................................................................................. 6 3.1 General requirements .................................................................................................... 6 3.2 Description of the standards .......................................................................................... 6 3.3 Special care ................................................................................................................... 9

4 Measurement instructions ..................................................................................................... 9 4.1 Step Height .................................................................................................................... 9 4.2 Roughness parameters................................................................................................ 10

5 Sofware measurement standard type F1: Softgauge.......................................................... 12 6 Measurement uncertainty.................................................................................................... 13 7 Reporting............................................................................................................................. 14 8 Comparison......................................................................................................................... 14

8.1 Reference value:.......................................................................................................... 14

Annex :

A.1 Measurement results : ....................................................................................................... 1 A.2 Softgauges measurement results : .................................................................................... 2 A.3 Inspection of the measurement surfaces........................................................................... 3 A.4 Description of the measurement instrument...................................................................... 4 A.5 Measurement uncertainty .................................................................................................. 5 A.6 Return Fax......................................................................................................................... 6

SIM - EURAMET Comparison L-K8 : Surface roughness 3

1 INTRODUCTION At EURAMET meeting in October 2007 it was proposed to initiate a comparison on surface roughness, this project was accepted as project n° 1003. The Pilot for the Euramet comparison is LNE – France. The last SIM.L-S2 comparison was published in 2004. At a SIM meeting in October 30-31 2006 it was decided to initiated the next regular surface roughness comparison for the SIM region, the SIM.L-K8 with NRC – Canada being the pilot. Taking into account the limited number of participants for both regions it was decided to merge the two planned comparisons into one. This protocol is approved by all participants from both regions.


2 ORGANIZATION

2.1 Participants

Country (code) Laboratory

Name of contact Address

EURAMET Labs

1 - Croatia (HR) DZM/LSFB - HMI

Vedran Mudronja

DZM/LSFB Ivana Lucica 5 HR-1000 Zagreb

Tel : 385 1 616 8327 Fax : 385 1 616 8599 e-mail : [email protected]

2 - Czech Republic (CZ) CMI Jirí Borovský

Czech Metrology Institute V Botanice 4 150 72 Praha 5

Tel : 420 257 288 319 Fax : 420 257 328 077 e-mail : [email protected]

3 – Estonia (EE) AS

Metrosert / TTU

Mats-Maidu Nanits

Tallinn Technical University (TTU) Laboratory of Mechanical Testing and Metrology

Tel : 202 372 620 3471 Fax : ? [email protected]

4 – Egypt (EG) NIS Mohamed A. Amer

National Institute of Standards Tersa Street – El Haram EG-12211 Giza

Tel : 372 620 3471 Fax : 372 620 3196 [email protected]

5 – Italy (IT) INRIM Gian Bartolo Picotto

Istituto Nazionale di Ricerca Metrologica Strade delle Cacce, 91, 10135 TORINO

Tel : 39 11 3919 969 or 973 Fax : 39 11 3919 959 e-mail : [email protected]

6 – France (FR) LNE Georges-Pierre Vailleau

LNE Laboratoire National de métrologie et d’Essais 1, rue Gaston Boissier F-75015 Paris

Tel : 33 1 40 43 37 77 Fax :33 1 30 16 28 31 e-mail : [email protected]

7 – Romania (RO) INM Alexandru Duta

National Institute of Metrology Sos. Vitan-Bârzesti Steet, No. 11 Sector 4 042 122 Bucharest

Tel : 40 21 334 50 60 Fax 40 21 335 533 [email protected]

8 - United Kingdom (GB) NPL Andrew

Lewis

National Physical Laboratory Dimensional Metrology Hampton Road TW11 OLW Teddington, Middlesex

Tel : 44 20 8943 6074 Fax :44 20 8614 0533 e-mail : [email protected]

SIM Labs

9-Argentina (AR) INTI Fernando Kornblit

INTI, Instituto Nacional de Tecnología Industrial, Centro de Investigación y Desarrollo en Física Av. Gral Paz 5445 (1650) Prov. De Buenos Aires Argentina

Tel. +(05411) 4 755 5402 Fax +(05411) 4 713 4140 e-mail: [email protected]

10-Brazil (BR) INMETRO Marcos Motta de Souza

INMETRO Instituto Nacional de Metrologia, Normalização e Qualidade Industrial DIMCI/DIMEC/LAMED Laboratório de Metrologia Dimensional Xerém, Duque de Caxias, R.J. Brazil

Tel. +55-21-2679-9726 Fax +55-21-26791505 e-mail: [email protected]

11-Canada (CA) NRC Kostadin Doytchinov

NRC/INMS Building M36, Room 136 Ottawa, Ontario K1A 0R6 Canada

Tel. +(613) 991-0265 Fax +(613) 952-1394 e-mail: [email protected]

12-Mexico (MX) CENAM Carlos Colin Castellanos

CENAM – Centro Nacional de Metrología, Edificio D División de Metrología Dimensional, km 4,5 Carretera a los Cués, C.P. 76246 El Marqués, Querétaro, MÉXICO

Tel. +52 –4-211-0500 Fax +52 –4-211-0577 e-mail: [email protected]

13-USA (US) NIST T. Brian Renegar

NIST 100 Bureau Drive, Stop 8212 Gaithersburg, MD 20899-8212 USA

Tel. +(301) 975-4274 Fax +(301) 869-0822 e-mail: [email protected]


2.2 Time schedule Each laboratory has one month for calibration, including transportation. With its confirmation to participate, each laboratory has confirmed that it is capable of performing the measurements in the limited time allocated. It guarantees, that the standards arrive in the country of the next participant at the beginning of the next month. If for some reasons, the measurement facility is not ready or customs clearance takes too much time in a country, the laboratory has to contact the coordinator immediately and – according to the arrangement made - eventually to send the standards directly to the next participant before finishing the measurements or even without doing any measurements.

Country Laboratory Date France LNE may 2009 Canada NRC june 2009 Brazil INMETRO july 2009

Mexico CENAM august 2009 Argentina INTI september 2009

USA NIST october 2009 Canada NRC november 2009 France LNE december 2009

Czech Republic CMI january 2009 Estonia AS Metrosert / TTU february 2010 Croatia DZM/LSFB - HMI march 2010

United Kingdom NPL april 2010 Italy INRIM may 2010

Romania INM june 2010 France LNE june-july 2010 Egypt NIS july 2010

France LNE august 2010 Canada NRC september 2010

2.3 Transportation The arrangement and the cost of transportation is the responsibility of each laboratory as the specimens travel from one laboratory to the next. The standards are packed in a sealed suitcase made of polypropylene filled with a suitable packing material. An ATA carnet is supplied at least for the SIM Labs. Each participant has to ensure that this carnet is joined to the package. The package can be shipped with any appropriate carrier, preferably using a fast mail service.


You are kindly asked to inform the pilot laboratory by Fax immediately after receiving the standards using the fax form in the annex. Immediately after having completed the measurements, the pack has to be sent to the next participant. It is advisable to prepare and organize this transportation beforehand. Please inform again the coordinator and the next laboratory by fax or e-mail about date of shipment, transportation company, flight details, etc.

2.4 Unpacking, Handling, Packing The suitcase contains the following items: - 4 standards in their leather package. - 1 copy of measurement instructions. - 1 CDROM containing the softgauges (ISO 5436-2:2001) and this protocol. After receiving the package, the standards have to be inspected carefully for any damage, scratches or rust. They must be handled with care! Any damage has to be communicated to the pilot laboratory. After the measurements, the standards have to be cleaned. Ensure that the content of the package is complete before shipment. Use always the original package.

2.5 Financial aspects, Insurance Each participating laboratory covers the costs for the measurements, transportation and eventual customs formalities as well as for any damages that may have occurred within its country. The overall costs for the organisation and for the devices are covered by LNE, the Euramet pilot laboratory. LNE has no insurance for any loss or damage of the standards during transportation.

3 STANDARDS

3.1 General requirements It was agreed by the participants to circulate one step height specimen and three surface roughness specimens. The participants should use the equipment and procedures normally used when calibrating client’s artifacts.

3.2 Description of the standards The package contains four standards in their leather package and enveloped in a lint free tissue: one type A1, two type C1 and one type D1 according to ISO 5436-1. All the standards are manufactured by Rubert & Co (http://www.rubert.co.uk). They are all made from electroformed nickel and have a hard protective top layer of nickel-boron.


3.2.1 Type A1 Standard : Rubert reference specimen model 511E (s/n P 224)

Figure 1 : Reference Specimen model 511 E

This standard has two wide grooves (G1 and G2) with flat bottoms with nominal values d = 1 µm and width = 100 µm. The grooves are roughly 25 mm long.

3.2.2 Type C1 standard : Rubert reference specimen model 527E (s/n PA 38)


This standard has a sine wave of nominal values: RSm = 100 µm, Ra = 3 µm and Pt = 10 µm.


3.2.3 Type C1 standard : Rubert reference specimen model 542E (s/n P 2225)


This standard has a sine wave of nominal value: RSm = 8 µm.

3.2.4 Type D1 standard : Rubert reference specimen model 503E (s/n P 61)


This standard has a unidirectional irregular profile with nominal value: Ra = 0,1 µm. It has a 1,25 mm long profile, which is repeated 4 times.


3.3 Special care

3.3.1 Avoidance of flaws

Sine wave standards might have some visible flaws. The user should avoid measuring paths that intersect flaws visible to the naked eye. In addition and more specifically, even single flaws in surface profiles, such as those shown in Figure 5, should be avoided because they can change the measured RSm value significantly. That is because the customary algorithms for calculating RSm rely on counting the crossings of the mean line (shown dashed here) by the surface profile. Single flaws such as these do not change the Ra values as significantly as they can change RSm.

Figure 5: Avoidance of flaws in surface measurements

4 MEASUREMENT INSTRUCTIONS Note: All the spacing values are given as an order of magnitude. They are not strict values, but following these values as close as possible will be best.

4.1 Step Height The standard model 511E has two grooves both are to be measured. The stylus instrument should scan the standard in a direction perpendicular to the grooves. The scanned data is to be “levelled” using a least squares best-fit line on the two portions marked A and B on the figure below. The step height is defined as the average depth (d) from the best-fitted least square line to the middle third of the bottom of the groove – see C in Figure 6. A total of 5 scans over the central 2 mm of each groove are to be performed (see Figure 7) and the average result together with a standard deviation is reported in the appropriate table in appendix A.


Figure 6: Assessment of the step height samples (ISO 5436-1:2000)

Ø25mm

G1G2

1.0m

m0.

5mm

1.0m

m0.

5mm

Figure 7: Measurements position for specimen 511E. Orientation is given in Figure 1.

The parameter to be calculated is d according to ISO 5436-1. If this cannot be measured, Pt (according to ISO 4287) may be substituted as an approximation, however the evaluation length for Pt should be limited to the equivalent region for the calculation of d.

4.2 Roughness parameters In order to reduce the influence of the standards the scans have to be done approximately in the same places. For each standard the measurement position are given below. The measurement parameters are given in Table 1. If it’s not possible then the parameters should be as close as possible to those mentioned in Table 1.


Standard Evaluation length (mm) λc (µm) λs (µm) Measuring

force (mN) Speed (mm/s)

Sampling spacing (µm)

Tip radius (µm)

C1 : 527E 4,00 800 2,5 < 1 = 0,5 = 0,5 2

C1 : 542E 0,40 80 2,5 < 1 = 0,5 = 0,5 2

D1 : 503E 1,25 250 2,5 < 1 = 0,5 = 0,5 2

Table 1 : Measurement parameters for each standard

A total of twelve measurements are to be performed using a sufficient traversing length so that after filtering the evaluation length amounts to five cut-offs (λc). The cut-offs filter is to be the ISO Gaussian type, discussed in ISO standard 11562:1996. The average result of the twelve measurements together with a standard deviation σmes is reported in the appropriate table in appendix A.

4.2.1 Rubert reference specimen model 527E (s/n PA 38) The scans are performed approximately according to the Figure 8 below.

38 mm

26 m

m

11 mm

5,2 mm

4 mm 0,8 mm

0,8 mm


The measurands are Ra, Rz, RSm, Rt according to ISO 4287:1997.

4.2.2 Rubert reference specimen model 542E (s/n P 2225)


18 mm

14 m

m

7,1 mm

5,4 mm

0,3 mm

0,3 mm

Figure 9: Measurements position for specimen 542E, evaluation length is 0,4 mm. Orientation is given in Figure 3.

The measurands are Ra, Rz, RSm, Rt according to ISO 4287:1997

4.2.3 Rubert reference specimen model 503E (s/n P 61)

1 mm

11 mm

5 m

m

1 mm

0,6 mm

1,25 mm 0,2 mm

0,1 mm

0,6 mm

0,3 mm

Measurement zone : 5x3 mm


The measurands are: Ra, Rq, Rz, Rt according to ISO 4287:1997.

5 SOFWARE MEASUREMENT STANDARD TYPE F1: SOFTGAUGE Two (2) softgauges in SMD format according to ISO 5436-2 are included in a CDROM to investigate software algorithms independently of hardware variation. WARNING : These softgauges are primary profiles and have had form removed (ISO 5436-2). Selected parameters are to be calculated according to ISO 4287-1.


The measurements conditions and parameters are listed in the table below.

File name Evaluation length (mm) λc (µm) λs (µm) Parameters

LK-8-Periodic 4,00 800 2,5 Ra, Rq, Rz, Rt, RSm

LK-8-Aperiodic 4,00 800 2,5 Ra, Rq, Rz, Rt, Rsk, Rku

Table 2 : Softgauges measurements conditions.

Note : The actual length of the primary profiles is 5,6 mm but one cut-off should be removed at each end.

6 MEASUREMENT UNCERTAINTY The uncertainty of measurement shall be estimated according to the ISO Guide for the Expression of Uncertainty in Measurement. From the measurements on each groove or roughness standard, a mean value of groove depth or parameters is to be determined. For each mean value an uncertainty of measurement is to be stated. To calculate the uncertainty of calibration of each groove depth or parameter, the participants should follow guidelines set out in the ‘ISO Guide to the Expression of Uncertainty in Measurement’. The full uncertainty calculation for each step height (depth) or parameter is to be presented with the results. Possible uncertainty components for a stylus measurement may include: Variation in measurement of reference and test pieces

• Calibration of a reference (reference standard uncertainty, orientation, noise…) • Drift • Linearity • Noise • Straightness of a datum • Stylus radius and angle • Stylus force • Filtering and cut-off • Traverse speed • …

Possible uncertainty components for interferometric methods may include:

• Calibration of a reference (reference standard uncertainty, orientation, noise…) • Variation in measurement of any reference and test pieces • Optical distortions / Aperture corrections • Alignment and Abbe errors • Resolution • Temperature and Humidity effect on wavelength • ….

Note: These lists are NOT conclusive and will vary for each system. Expected values may vary for individual tests. Participants should estimate as best as possible the contributing components of their specific system. In each calculation the laboratory must also list the source of each component value. Eg., Reference uncertainty taken from calibration report.


7 REPORTING The quality of the measurement surfaces of the standards, the measurement results, instrument descriptions and a detailed evaluation of the uncertainty of measurement have to be reported using the forms enclosed in the annex. Handwritten notes are sufficient. The measurement report forms in the annex of this document are sent by e-mail (Word document) to all participating laboratories. It would be appreciated if the report forms (in particular the results sheet) could be completed by computer and sent back electronically to the coordinator. In any case, the signed report must also be sent in paper form by mail. In case of any differences, the paper forms are considered to be the valid version. The reports shall be sent within six weeks after completing the measurements to the pilot laboratory. No information about differences of the reported results with respect to others will be communicated before the completion of the comparison, unless large deviations of particular laboratories with respect to the preliminary reference results obtained by the pilot laboratory have been observed. In the latter case the laboratory in question will be contacted.

8 COMPARISON Within 3 months after completion of the circulation, the pilot laboratories will prepare a first draft report and send it to the participants for comment. Subsequently, the procedure outlined in the BIPM Guidelines will be followed.

8.1 Reference value: For the comparison the distribution of the measured values is assumed to be normal. The reference value can be calculated using different approaches. The weighted mean approach has been used for some previous Key Comparisons. However, we prefer the simple arithmetic mean as the reference value. This is because the uncertainty of the weighted mean is based largely on claimed uncertainties by the participants whereas the uncertainty of the simple mean is the standard deviation calculated from the measured results. Below are the formulae for the simple mean and its uncertainty:

nxxx

x nref

K++= 21

( ) ( )( )1

2

−

−= ∑

nnxx

xu iref

The agreement between the different labs and the reference value will be evaluated using En (k=2) value :

( ) ( )( )refi

refin

xuxu

xxE

222 +⋅

−=


After completion of the comparison if all En values are smaller than 1 it will be considered that there is a good agreement between the participating labs and the calculated reference value. If there are NMIs whose results cause En>1, then these NMIs must make sure that the uncertainties presented for Appendix C of the MRO are consistent with the results of this comparison to be entered in Appendix B of the MRO.

SIM - EURAMET Comparison L-K8 : Surface roughness A 1

Laboratory :.....................................................................................................................

Date : ........................................... Signature :..................................................

APPENDIX A :

A.1 MEASUREMENT RESULTS : Standard model 511E

Groove Parameter Value (nm) σmes uc (nm) neff

G1 d

G2 d

Standard model 527E

Parameter Value (µm) σmes uc (nm) neff

Ra

Rz

Rt

RSm

Standard model 542E


Ra

Rz

Rt

RSm

Standard model 503E


Ra

Rz

Rt


Laboratory :.....................................................................................................................

Date : ........................................... Signature :..................................................

A.2 SOFTGAUGES MEASUREMENT RESULTS :

Parameter LK-8 periodic LK-8 Aperiodic

Ra (nm)

Rq (nm)

Rz (µm)

Rt (µm)

RSm (µm)

Rsk

Rku


Laboratory :.....................................................................................................................

Date : ........................................... Signature :..................................................

A.3 INSPECTION OF THE MEASUREMENT SURFACES

STANDARD 527E

BEFORE AFTER

STANDARD 542E

BEFORE AFTER

STANDARD 503E

BEFORE AFTER

STANDARD 511E

BEFORE AFTER


Laboratory :.....................................................................................................................

Date : ........................................... Signature :..................................................

A.4 DESCRIPTION OF THE MEASUREMENT INSTRUMENT

Make and Type of apparatus .......................................................................................

........................................................................................................................................

........................................................................................................................................

Vertical measurement traceability: ......................................................................

Transverse measurement traceability: ................................................................

........................................................................................................................................

........................................................................................................................................

Stylus ............................................................................................................................

Manufacturer :..................................................................................................... Radius :............................................................................................................... Angle :...............................................................................................................

........................................................................................................................................

Sampling spacing : .......................................................................................................

........................................................................................................................................

........................................................................................................................................

Speed : .......................................................................................................................... ........................................................................................................................................

Measuring force :.......................................................................................................... ........................................................................................................................................

........................................................................................................................................

Analysis Software :....................................................................................................... Home made / commercial : .................................................................................

Version n° :..........................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................

........................................................................................................................................


Laboratory :.....................................................................................................................

Date : ........................................... Signature :..................................................

A.5 MEASUREMENT UNCERTAINTY

Component u(xi) ni ci = ∂l/∂xi ui(l)

Combined standard uncertainty : u lc ( ) =


A.6 RETURN FAX Telefax Telefax Telefax Telefax Telefax

To : LNE JOSE SALGADO 1, rue Gaston Boissier 75724 PARIS Cedex 15

Tel : 33 1 40 43 39 57 Fax : 33 1 30 16 28 31 Email : [email protected]

From : ................................................................. (participating laboratory) SIM - EURAMET L-K8

We confirm having received the standards of the SIM - EURAMET comparison L-K8 on surface roughness measurement on ..............................................(date).

After visual inspection

• no damage has been noticed.

• the following damage(s) must be reported : ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................

Date : Signature :

............................................ ..............................................................

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EURAMET.L-K8 Technical Protocol - KCDB - BIPM