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Instrumentation and Measurements
Dr. Mohammad Kilani
Class 1Introduction
Department’s Website
www.uj-mechatronics.net
Home
Welcome to UJ-Mechatronics, the website of the Mechatronics Engineering Department of the University of Jordan. Our mission is to equip our
students with a solid understanding of the principles of mechanical engineering, electrical engineering, electronics, control systems and
information technology to a level that allows them to employ the latest developments in those fields for the advancement of engineering
systems in general, and mechatronic systems in particular. To that end, we have prepared a multidisciplinary program of study, established
eight multidisciplinary engineering labs, and attracted an internationally-recognized academic staff to work with our students on designing and
building engineering systems with improved efficiency, reliability, cost and environmental footprint.
Whether you are a current student, an alumni, or a prospective student, I hope that you find the information in this site useful.
Mohammad I. Kilani, Department Head
Department Courses
Mandatory Department Courses
Control Systems (0908441)
Engineering Measurements and Instrumentation (0908341)
Hydraulic and Pneumatic Systems for Mechatronics (0908537)
Measurements and Control Lab (0908448)
Mechatronics Systems Design (0908531)
Modelling and Simulation (0908312)
Modern Control Systems(0908442)Power Electronics for Mechatronics (0908461
)
Elective Department Courses
Automation (0908561)
Autotronics (0908481)Drive Systems (0908582)Hydraulic
and Pneumatic Control (0908543)Industrial
Process Control (0908545)Intelligent Control (0908541)
Microelectromechanical Systems (MEMS) (0908575)Robotic
Systems (0908563)Selected Topics in Mechatronics (0908589)
Transducers (0908443)System Integration (0908571)
Study Plan
Graduation Course Requirements (PDF-264KB)
Tree-Structured Plan (PDF-81KB)
Semester Plan (PDF-1MB)
Course Description (PDF-660KB)
Staff
Academic Staff
Lutfi Al-Sharif, 06/5355000 ext 23027, [email protected],
Mohammad Al-Janaideh, ext 23007, [email protected]
Mohammad Kilani, ext 23025, [email protected]
Osama Al-Habahbeh, ext , [email protected]
Ratib Issa, ext 22814, [email protected]
Za’er Abo-Hammour, ext 23026, [email protected]
Engineering Staff
Hesham Mohammad, ext 23028, [email protected]
Nadeen Habash, ext 23028, [email protected]
Nazmi Abu-Ashour, ext 23029, [email protected]
Nisreen Al-Amayreh, ext 23028, [email protected]
Osama Abdel A’al, ext 23028, [email protected]
Rasha Noufal, ext 23028,[email protected]
Safaa Al-Wreadat, ext , [email protected]
Labs and Facilities
Automation Lab
Hydraulics and Pneumatics Lab
Measurements and Control Lab
Mechatronics System Design Lab
Transducers Lab
Forms and Instructions
Alternative Course Form
Closed Section Registration Form
Course Drop Form
Course Grade Revision Form
Graduation Project Forms and Instructions
Student Release Form
Posts and Announcements
Department Posts and Announcements
Staff Posts and Announcements
Course Posts and Announcements
Introduction to Measurements
Measurement techniques have been of immense importance
ever since the start of human civilization, when measurements
were first needed to regulate the transfer of goods in barter
trade to ensure that exchanges were fair. The industrial
revolution during the nineteenth century brought about a
rapid development of new instruments and measurement
techniques to satisfy the needs of industrialized production
techniques.
Applications of Measurement Systems
1. Regulating trade
2. Monitoring to allow human beings to take some action accordingly
3. Use as part of automatic feedback control systems
The Five Senses
1. See
2. Hear
3. Touch
4. Taste
5. Smell
Limitations of Unassisted Measurements
Sensing PrinciplesThe interaction of physical parameters with each other—most notably electricity with stress, temperature and thermal gradients, magnetic fields,
and incident light—yields a multitude of sensing techniques which may be applied in measurements
Transductive
Piezoelectric
Thermoelectric
Photoelectric
etc.
Constitutive
Resistive
Capacitive
Inductive
Etc.
Pressure
Temperature
Light
Current
Voltage
Other.
Transducer
Pressure
Temperature
Light
R, C. L, etc
Sensor
Standardization of Units
Establishment of standards for the measurement of
physical quantities proceeded in several countries at
broadly parallel times, and in consequence, several sets
of units emerged for measuring the same physical
variable.
An internationally agreed set of standard units (SI units
or Syst`emes Internationales d’Unit´es) has been
defined, and strong efforts are being made to encourage
the adoption of this system throughout the world.
Standard Units
Fundamental Units andSupplementary Fundamental Units
Derived Units
Elements of a Measurement Systems
In simple cases, the system can consist of only a single
unit that gives an output reading or signal according to
the magnitude of the unknown.
However, in more complex measurement situations, a
measuring system consists of several separate
elements. These components might be contained
within one or more boxes, and the boxes holding
individual measurement elements might be either close
together or physically separate.
Elements of a Measurement Systems
In simple cases, the system can consist of only a single
unit that gives an output reading or signal according to
the magnitude of the unknown.
However, in more complex measurement situations, a
measuring system consists of several separate
elements. These components might be contained
within one or more boxes, and the boxes holding
individual measurement elements might be either close
together or physically separate.
Elements of a Measurement Systems
[Morris, Measurement & Instrumentation Principles]
Measured Variable
SensorVariable Conversion
ElementSignal Processor
Use of Measurement at Remote
Location
Signal Transmission
Presentation / Recording
Unit
Output
Elements of a Measurement Systems
[Figliola, Theory and Design of Mechanical Measurements]
Elements of a Measurement Systems: Sensor
A sensor gives an output that is a function of the
measurand (the input applied to it).
For most but not all sensors, this function is at least
approximately linear.
Some examples of primary sensors are a liquid
mercury in the liquid-in-glass thermometer, a
thermocouple and a strain gauge.
Examples Sensors
Liquid Mercury
Input: Temperature
Output: Mercury volume
Are these linear sensors?
Thermocouple
Input: Temperature
Output: Voltage
Strain gauge
Input: Strain
Output: Electric resistance
Examples Sensors
Liquid Mercury Thermometer
Measured Variable: Temperature
Sensor: Liquid Mercury
Variable Conversion Element: Stem
Signal Presentation Element: Display Scale
Elements of a Measurement Systems: Variable Coversion Element
Needed where the output variable of a primary sensor is in an
inconvenient form and has to be converted to a more convenient
form.
The displacement-measuring strain gauge has an output in the form
of a varying resistance. The resistance change cannot be easily
measured and so it is converted to a change in voltage by a bridge
circuit, which is a typical example of a variable conversion element.
In some cases, the primary sensor and variable conversion element
are combined, and the combination is known as a transducer.
Elements of a Measurement Systems: Signal Processing Element
Improve the quality of the output of a measurement system.
A very common type is the electronic amplifier, used when the primary transducer has a low output. For example, thermocouples have a
typical output of only a few millivolts.
Other signal processing element are those that filter out induced noise and remove mean levels etc. In some devices, signal processing
is incorporated into a transducer, which is then known as a transmitter.
Elements of a Measurement Systems: Signal Transmission
Needed when the observation or application point of the output of a
measurement system is some distance away from the site of the
primary transducer.
It has traditionally consisted of single or multi-cored cable, which is
often screened to minimize signal corruption by induced electrical
noise.
Fibre-optic cables are being used in ever increasing numbers in
modern installations because of their low transmission loss and
imperviousness to the effects of electrical and magnetic fields.
Elements of a Measurement Systems: Signal Presentation or Recording Unit
The final optional element in a
measurement system.
It may be omitted altogether when the
measurement is used as part of an
automatic control system.
It takes the form either of a signal
presentation unit or of a signal-
recording unit.
Elements of a Measurement Systems
Measured Variable
SensorVariable Conversion
ElementSignal Processor
Presentation / Recording
Unit
Elements of a Measurement Systems
SensorVariable Conversion
ElementSignal Processor
Signal Transmission
Presentation / Recording
Unit
Transducer
Measured Variable
Elements of a Measurement Systems
SensorVariable Conversion
ElementSignal Processor
Signal Transmission
Presentation / Recording
Unit
Transducer
Measured Variable
Transmitter
Case Study 1Resistive Temperature Detector (RTDs)
Resistance temperature detectors (RTDs), are sensors
used to measure temperature by correlating the
resistance of the RTD element with temperature.
Most RTD elements consist of a length of fine coiled wire
wrapped around a ceramic or glass core. The RTD
element is made from a pure material whose resistance
at various temperatures has been documented; The
change in resistance is used to determine temperature.
Case Study 1Resistive Temperature Detector (RTDs)
Although most metals can in theory be used in RTDs,
only a few have been practically applied.
RTD elements are normally constructed of platinum,
copper, or nickel. These metals are suited for RTD
applications because of their linear resistance-
temperature characteristics, their high resistive
temperature coefficient, and their ability to withstand
repeated temperature cycles.
Case Study 1Resistive Temperature Detector (RTDs)
The coefficient of resistance is the change in resistance per
degree change in temperature, usually expressed as a
percentage per degree of temperature. The material used must
be capable of being drawn into fine wire so that the element
can be easily constructed.
Case Study 1Resistive Temperature Detector (RTDs)
With proper circuitry (e.g., Wheatstone
bridge), the change in resistance can be
converted into a change in voltage.
The combination then becomes a
temperature transducer
Case Study 1Resistive Temperature Detector (RTDs)
The simplest bridge configuration uses two wires. It
is used when high accuracy is not required, as the
resistance of the connecting wires is added to that
of the sensor, leading to errors of measurement.
This configuration allows use of 100 meters of cable.
Ru
R3 R
2
R1
Vo
Vi
213 RRRRu
When the bridge is balanced, Vo = 0
21
1
3 RR
R
RR
RVV
u
uio
Homework
Suggest an alternative configuration to eliminate the
effect of lead resistance. Be prepared to present
your suggestion on class this Thursday.
Make a team with four students per team.
Ru
R3 R
2
R1
Vo
Vi
213 RRRRu
When the bridge is balanced, Vo = 0
21
1
3 RR
R
RR
RVV
u
uio
Choosing appropriate measuring instruments
Accuracy, resolution, sensitivity and dynamic performance.
Environmental conditions that the instrument will be subjected to. Measurement systems and
instruments should be chosen that are as insensitive as possible to the operating environment.
The extent to which the measured system will be disturbed during the measuring process is
another important factor in instrument choice. For example, significant pressure loss can be
caused to the measured system in some techniques of flow measurement.
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