Measurement and control

1. Pimpri Chinchwad Polytechnic, Nigdi
Introduction of Measurement
 Subject: Measurement And Control (17528)
 Chapter :01 Introduction and Significance of Measurement
 Class:DME 5th Semester
Prepared By:
Ms. Nilesha U.Patil

2. Session Objectives
 General Objectives:
After completing this session, you will be able to:
 Understand the term Measurement
 Specific Objectives:
After completing this session, you will be able to:
 Define the term Measurement
 Study significance of measurement
 Explain static and dynamic characteristics of measurement
 Measure and explain different types of error
 Describe different types of error.

3. Measurement Definition
 It is process of determining the value of magnitude of
an unknown quantity by comparing it with some
predetermined standard of reference.
 It is process whereby one can convert physical
parameters or chemical properties to meaningful
numbers.

4. Contd..
 It is the process or an act of obtaining a quantitative
comparison between predetermined standard and
unknown magnitude.
Input OutputProcess of
comparison

5. Significance of Measurement
 Study the functioning of different components which
comprise a particular system.
 It is also a fundamental element of any control process.
 Many operations required measurement for proper
performance. e.g. temperature, pressure, central power
station.
 Modern era of AMS is fully dependent on
measurement
 It is fundamental basis for all research, design,
production, processing etc.

16. Methods Of Measurement
 I) Direct Measurement: unknown quantity is directly
compared with a standard.
 E.g. To measure length of steel bar by comparing it
with scale
 Determination of weight by balance.

17. Indirect Measurement
 Measurand is converted into some effect which can be
measured.
 Direct measurement are always not possible, feasible
and practicable.

18. Other methods
 II)
 i) Primary
 ii) Secondary
 iii) Tertiary
 III)
 i)Contact type
 ii)Non-Contact type

19. Instrument
 An instrument is a device which senses a physical
parameter, process and translates it into a format
which can be interpreted by the observer.

20. Desirable qualities of an ideal
instrument
 It must be accurate and sensitive
 It should be sufficiently strong
 It should have low cost
 It should be safe for operation
 It must be reliable

21. Classification of instrument
Instrument can be classified on the basis of following:
 I) method of contact
 i) contact type
 ii) non-contact type
 II) Mode of operation
 i) manual operated
 ii) automatic operated
 III) Source of energy
 i) self operated
 ii) power operated

22. Contd..
 IV) Arrangement of physical parts
 i) self contained instrument
 ii) remote indicating instrument
 V)Output display
 i) Null type
 ii) deflection type
 VI) Output signal
 i) Analog
 ii) digital
 VII) Application
 i) Mechanical
 ii) Electrical
 iii) Electronics

23. Static terms and characteristics
 Range and span
 Accuracy and precision
 Reliability
 Repeatability and reproducibility
 Calibration
 Hysteresis
 Dead time and dead zone
 Drift
 Sensitivity
 Threshold and resolution
 Linearity and non linearity

24. THANK YOU…