The document provides an introduction to instrumentation and measurement within engineering, detailing key concepts such as physical quantities, data acquisition, and the classification of sensors and transducers. It also covers various methods of measurement (e.g., temperature, pressure, and flow) and emphasizes the importance of accurate data collection for improving manufacturing efficiency and product quality. Additionally, it outlines errors in measurements, characteristics of measuring instruments, and presents a structured overview of different measurement units.

1. LECTURE 1: INTRODUCTION
Kamlesh T. Kahar
Faculty of Elect. & Telecommunication Engineering
SSGMCE

2.  Instrumentation
◦ It is the branch of engineering that deals with
measurement & control of process variables within a
production/manufacturing area.
 Measurement
◦ A method to obtain information regarding the
physical values of the variable.
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3.  Physical quantity: variable such as pressure,
temperature, mass, length, etc.
 Data: Information obtained from the
instrumentation/measurement system as a result of
the measurements made of the physical quantities
 Information: Data that has a calibrated numeric
relationship to the physical quantity.
 Parameter: Physical quantity within defined
(numeric) limits.
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4. 4
measurand Sensor, signal conditioning, display Man, tracking control etc

5.  Measurand: Physical quantity being measured.
 Calibration: Implies that there is a numeric
relationship throughout the whole instrumentation
system and that it is directly related to an approved
national or international standard.
 Test instrumentation: It is a branch of
instrumentation and most closely associated with the
task of gathering data during various development
phases encountered in engineering, e.g. flight test
instrumentation for testing and approving aircraft.
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Terminology

6.  Transducer: A device that converts one form of
energy to another.
 Electronic transducer: It has an input or output that is
electrical in nature (e.g., voltage, current or
resistance).
 Sensor: Electronic transducer that converts physical
quantity into an electrical signal.
 Actuator: Electronic transducer that converts
electrical energy into mechanical energy.
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7.  In the case of process industries and
industrial manufacturing…
◦ To improve the quality of the product
◦ To improve the efficiency of production
◦ To maintain the proper operation.
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8.  To acquire data or information (hence data
acquisition) about parameters, in terms of:
◦ putting the numerical values to the physical
quantities
◦ making measurements otherwise inaccessible.
◦ producing data agreeable to analysis (mostly in
electrical form)
 Data Acquisition Software (DAS) – data is
acquired by the instrumentation system.
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9.  Direct comparison
◦ Easy to do but… less accurate
 e.g. to measure a steel bar
 Indirect comparison
◦ Calibrated system; consists of several devices to
convert, process (amplification or filtering) and
display the output
 e.g. to measure force from strain gages located in a
structure
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10.  Stage 1: A detection-transducer or sensor-transducer, stage; e.g.
Bourdon tube
 Stage 2: A signal conditioning stage; e.g. gearing, filters, bridges
 Stage 3: A terminating or readout-recording stage; e.g. printers,
oscilloscope
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General Structure of Measuring System

11.  Passive Instruments
◦ the quantity being measured simply modulates (adapts to)
the magnitude of some external power source.
 Active Instruments
◦ the instrument output is entirely produced by the quantity
being measured
 Difference between active & passive instruments is the level of
measurement resolution that can be obtained.
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12.  e.g. Float-type petrol tank level indicator
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13.  The change in petrol level moves a potentiometer
arm, and the output signal consists of a proportion of
the meter reading which varies according to the
position of float.
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14.  e.g. Pressure-measuring device
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15.  The pressure of the fluid is translated into a
movement of a pointer against scale.
 The energy expanded in moving the pointer
is derived entirely from the change in
pressure measured: there are no other
energy inputs to the system.
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16.  An analogue instrument gives an output that
varies continuously as the quantity being
measured; e.g. Deflection-type of pressure
gauge
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17.  A digital instrument has an output that varies
in discrete steps and only have a finite
number of values; e.g. Revolution counter
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18.  Home
◦ Thermometer
◦ Barometer
◦ Watch
 Road vehicles
◦ speedometer
◦ fuel gauge
 Industry
◦ Automation
◦ Process control
◦ Boiler control
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19. Unit-I : Basics of Transducers
 Transducer: Definition, Classification, Selection criteria.
Errors, loading effects, Transducer Specifications,
calibration, Generalized Instrumentation diagram.
 Static characteristics: Accuracy, Precision, Sensitivity,
Threshold, Resolution, Repeatability and Hysteresis.
 Errors: Gross error, Systematic error, Random error,
Limiting error.
 Statistical Parameters: Arithmetic mean Average
deviation Standard deviation. Probable error, Histogram,
Normal & Gaussian curve of errors.
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20. Unit-II : Measurement of Displacement, Liquid Level
 Measurement of Displacement:
Resistive, Capacitive, Inductive
 Measurement of Liquid Level: Resistive, Capacitive,
Inductive, Ultrasonic, Gamma Rays.
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21. Unit-III : Measurement of Temperature
Measurement of Temperature: Resistance temperature
detector (RTD): Principle, types, Configurations,
construction and working of RTD, Material for RTD,
advantages, disadvantages and applications of RTD.
Thermistors: Principle, types (NTC and PTC), characteristics,
Construction and working of Thermistor, Materials,
specifications of Thermistor, applications.
Thermocouples: Principle, thermoelectric effect, See beck
effect, Peltier effect, laws of thermocouple, cold junction
Compensation method, thermopile, thermocouple emf
measurement method.
Pyrometers: Principle, Construction and working of Radiation and optical
pyrometers and its Applications, LM 335.
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22. Unit-IV : Measurement of Pressure, Flow, Humidity.
◦ Measurement of Pressure: Primary pressure sensors - elastic
elements like bourdon tube, diaphragm, and bellows.
Electrical/Secondary Pressure
◦ Transducers: Capacitive, piezo-electric and its material,
variable reluctance, LVDT.
◦ Differential pressure measurement: Capacitive. Low Pressure
(Vacuum): Pirani gauge, thermocouple gauge, hot cathode
ionization gauge.
◦ Flow Measurement: ultrasonic, electromagnetic & hotwire
Anemometer.
◦ Flow Measurement: ultrasonic, electromagnetic & hotwire
Anemometer.
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23. Unit-V : Measurement of Velocity, Strain & Miscellaneous Sensors
Velocity Measurement: Using photo detectors (both
linear & angular velocity), Stroboscope.
Strain Measurement: Introduction, types of strain gauge,
gauge factor calculation, materials for strain gauge,
resistance strain gauge bridges, temperature compensation
and applications of strain gauges.
Miscellaneous Sensors: Noise (sound) Sensors
Characteristics of sound, levels of sound pressure, sound
power and sound intensity.
Smart sensors: Objective, block diagram, advantages and
disadvantages.
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24. Unit-VI : Data acquisition and applications of
Electronic Instruments
◦ Analog & Digital data acquisition system.:
Generalized block diagram of data acquisition
system(DAS), objective of DAS, signal conditioning of
inputs, single channel DAS, Multichannel DAS,
computer based DAS
◦ Digital transducer: optical encoders, shaft encoders
◦ pH and blood pressure measurement.
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25. Sr.No. Title Author Publications
1 A course in Electrical and Electronic Measurement
and Instrumentation
Sawhney A.K. Dhanpat Rai & Sons.,
Delhi
2 Electronics Instrumentation H. S. Kalsi Tata McGraw Hill, 2nd
Edition
3 Instrumentation Measurement & analysis B C Nakra Tata Mc-Graw Hill.
4 Instrumentation, devices and systems Rangan Mani, Sharma Tata Mc-Graw Hill.
5 Electronics Instrumentation U.A. Bakshi & A. V.
Bakshi
Technical
Publication
6 Modern Electronic Instrumentation and
Measurement Tech
Helfrick, Cooper Prentice hall
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