Instrumentation

& Measurements

Who am I ?Khan M. Nazir

MSc(Elect Engg), UET Lahore.Served in Pakistan Army Corps of Electrical & Mechanical Engineering for 22 years.Served as Military Technical Liaison Officer in USA for more than Four years. Also served as country manager for a Japanese parts manufacturing companyWas Instructor in Army; taught Radar & Control Equipment. Teaching University students since 1998. Have taught Basic Electronics, Signals & Systems, Communication Systems, Digital Logic Design, Circuit –I , Circuit-II, Electrical Machines, Instrumentation & measurements, Engineering Management, and Engineering Ethics.

By the Grace of Almighty Allah, had the opportunity to see following countries:

USA, UK, Canada, Japan, China, Malaysia, Thailand, Hong Kong, Argentina, Brazil, Bangladesh, and Saudi Arabia.

Grading Policy

• Quizzes & Assignments - 25 Marks

• Mid - 25 marks

• End-term - 50 marks

Grading Policy…..

• There will be 4 quizzes (Two quizzes before mid and

two after mid ) and 1 assignment (project) each carrying 5 graded marks.

• Each quiz will be followed by a repeat quiz for the poor performers and absentees. The

repeat quiz will have 80% weightage.

How to get a good grade ?

Attendance Policy

• Max 7 absentees allowed (after add/drop period).

• Attendance will be taken in the first 5 minutes.

• No marks are allotted for being regular/punctual in class, but this may help if you are a borderline case.

Upon Completion of the course, the students will be able to:-

a. Define Characteristics of Instrumentation and Measurements.b. Define Types of Errors and Carry out Error Analysisc. Differentiate between Units and Dimensions and Carry out Dimensional Analysisd. Explain various types of Standards of Measurements and Measurement Methods, and carry out Statistical Analysis.e. Explain Different types of Measuring Instruments and Calculate Various Parameters.f. Perform Resistance, Inductance, Capacitance, and frequency Measurements using Bridge Circuits.g. Discuss working of Electronic Instrumentsh. Explain Working of Various Types of Display Devices, including Oscilloscopes, Plotters, and Spectrum Analyzers.i. Design Signal Conditioning CircuitsJ. Explain various Types of Sensors, and Design Data Acquisition System.K. Discuss working of High Voltage Measurement Systems.

Instrument : Tool or equipment for

• Sensing• Detecting• Measuring• Recording• Controlling• Communicating

Instruments used in Industry

• Process instrumentation and –analytics for the pharmaceutical and life science industries

• Pressure Measurement• Temperature Measurement• Flow Measurement• Level Measurement• Valve Positioning• Weighing Technology• Gas Analytics• Industrial Communication

•Elements of a generalized measurement system

Elements of a generalized measurement system….

Part-2

Characteristics of Instruments and Measurement Systems

Performance Characteristics of measurement systems

• A knowledge of the performance characteristics of instruments is very important for selecting the most appropriate instrument for a specific measuring job.

• It consists of two characteristics: namely ‘static’ and ‘dynamic’ characteristics.

•Static characteristics

Static Performance of Instrument

• The following terms specify the static characteristics of the measuring systems and devices:

1. Accuracy 10. Scale Readability 19. Linearity

2. Precision 11. Stability 20. Instrument Hysteresis

3. Bias 12. Zero Stability 21. Dead Time

4. Repeatability 13. Resolution 22. Dead Zone

5. Tolerance 14. Responsiveness 23. Friction

6. Reliability 15. Drift 24. Backlash

7. Deviation 16. Uncertainty 25. Overshoot

8. Scale Span 17. Static Sensitivity

9. Live Zero 18. Instrument Efficiency

Accuracy

• The only time a measurement can be exactly correct is when it is a count of a number of items.

• In all other cases there will be difference between the true value and the measured value by an instrument. That is, there will be measurement error.

* Accuracy refers to the degree of closeness to the True value of the quantity under measurement.

PrecisionPrecision is the measure of consistency or

 repeatably of measurement.

• Precision is an indicator of the closeness between repeated readings (Readings do not have to be close to an expected or true value to be

considered precise, they just need to be close to each other )

Resolution• Resolution is the fineness to which an

instrument can be read.

What is the resolution here ?

Sensitivity

• Sensitivity is the smallest unit of a given parameter that can be meaningfully detected with the instrument when used under reasonable conditions.

• For example, assume the sensitivity of a DMM in the volts function is 100 nV. With this sensitivity, the DMM can detect a 100 nV change in the input voltage.

Sensitivity to disturbance

•Dynamic characteristics