CONTENTS
1. TRANSDUCERS AND BRIDGES
1.1
1.2
Measurements
1.1
1.1.1
Introduction
1.1
1.1.2
Significance of Measurements
1.1
1.1.3
Aims of Measurement
1.2
1.1.4
Methods of Measurements
1.2
1.1.5
Types of Measurements
1.3
1.1.6
Applications of Measurement Systems
1.4
Instrumentation
1.6
1.2.1
Functional Elements of Measurement System
1.7
1.2.1.1 Example for the concept of measurement system
1.9
1.2.2
Classification of Instruments used in Instrumentation System
1.9
1.2.3
Performance Characteristics
1.13
1.2.3.1 Static characteristics
1.14
1.2.3.2 Dynamic characteristics
1.20
1.3
Errors in Measurements
1.21
1.4
Static Calibration of Instruments
1.27
1.5
Standards
1.30
1.6
Transducers
1.44
1.6.1
Introduction
1.44
1.6.2
Selection of Transducers
1.45
1.6.3
Classification of Transducers
1.46
1.6.4
Characteristics of Transducers
1.48
1.7
1.8
1.9
D.C.Bridges
1.54
1.7.1
Wheatstone bridge
1.54
1.7.2
Carey-Foster slide wire bridge
1.60
1.7.3
Kelvin Double bridge
1.66
A.C.Bridges
1.8.1
Maxwell’s Inductance-Capacitance bridge
1.73
1.8.2
Hay’s bridge
1.75
1.8.3
Anderson’s bridge
1.77
1.8.4
Owen’s bridge
1.80
1.8.5
Schering bridge
1.81
1.8.6
Wlen’s bridge
1.84
Electrical Weighing system
1.9.1
1.93
Load cell and strain gauge arrangement for
electrical weighing system
2.
1.68
1.93
1.10
Electronic Weighing system
1.98
1.11
Multimeters
1.101
1.12
True RMS Voltmeter
1.104
1.13
Short questions and answers
1.105
DATA DISPLAY AND RECORDING SYSTEM
2.1
Cathode ray oscilloscope (CRO)
2.1
2.2
Cathode ray tube (CRT)
2.3
2.2.1
2.4
Electron gun
2.2.2
Electrostatic and magnetostatic focusing
2.5
2.2.3
Electrostatic and electromagnetic deflection
2.10
2.2.4
Post deflection acceleration (PDA)
2.16
2.2.5
Effect of beam transit time and frequency limitations
2.18
2.2.6
Screen for CRTs
2.18
2.2.7
Graticules
2.20
2.3
Time base generators
2.21
2.4
Vertical deflection system
2.23
2.5
Horizontal deflection system
2.25
2.6
Trigger circuit
2.25
2.7
Delay line
2.28
2.8
CRO Applications
2.31
2.8.1
Voltage and current measurements
2.32
2.8.2
Phase measurements
2.32
2.8.3
Frequency measurements
2.34
2.9
Dual trace CRO
2.43
2.10
Dual beam CRO
2.45
2.11
Analog storage oscilloscope
2.46
2.11.1 Variable persistence storage
2.50
2.11.2 Bistable storage
2.51
2.11.3 Fast storage type CRT
2.52
Digital storage oscilloscope
2.52
2.12
2.13
Sampling oscilloscope
2.55
2.14
Recorders
2.57
2.14.1 Strip chart recorder
2.58
2.14.2 X-Y recorder
2.59
2.14.3 Magnetic tape recorders
2.60
2.14.4 Galvanometer type recorders
2.63
2.14.5 Null type recorders
2.66
2.14.6 Potentiometric recorders
2.66
2.14.7 Oscillographic or ultraviolet recorder
2.68
2.14.8 Methods of recording in magnetic tape recorders
2.69
2.14.9 Digital tape recordes
2.78
Q-Meter
2.83
2.15.1 Measurement Methods
2.85
2.15.2 Source of Error
2.91
2.16
Vector Voltmeter
2.96
2.17
RF Voltage and Power Measurements
2.100
2.17.1 RF Voltage Measurement
2.100
2.17.2 RF Power Measurements
2.101
Short Questions & Answers
2.102
2.15
2.18
3.
SIGNAL GENERTORS AND SIGNAL ANALYZERS
3.1
Introduction to Signal generators
3.1
3.2
Sine-wave generator
3.1
3.3
3.4
3.5
Audio-frequency generator
3.4
3.3.1
A.F.Generator using Wien’s Bridge Oscillator
3.5
3.3.2
A.F Generator using Phase Shift Oscillator
3.12
Pulse generators
3.15
3.4.1
Pulse Characteristics and Terminology
3.17
3.4.2
Pulse Wave Circuits
3.19
3.4.3
Laboratory type Pulse generator
3.25
3.4.4
Pulse generator circuit
3.27
AM/FM Signal generator
3.30
3.5.1
A.M. Signal generators
3.30
3.5.2
F.M. Signal generator
3.33
3.6
Function generator
3.35
3.7
Sweep frequency generators
3.38
3.8
Wave Analyzers
3.44
3.9
Spectrum Analyzers
3.47
3.10
Fourier Transfrom Spectrum Analyzers
3.55
3.11
Distortion Analyzers
3.59
3.11.1 Types of Distortion
3.60
3.11.2 Total Harmonic Distortion
3.61
3.11.3 Heterodyne Harmonic Analyzer or Wavemeter
3.62
3.11.4 Fundamental Suppression Harmonic Distortion Analyzer
3.62
3.11.5 Intermodulation Distortion Analyzer
3.64
4.
3.11.6 Transient Intermodulation Distortion
3.66
3.12
RF Signal Generators (standard Signal Generator)
3.66
3.13
Frequency Synthesizer
3.69
3.14
Short Question and answers
3.72
DIGITAL INSTRUMENTS
4.1
Digital voltmeters
4.1
4.1.1
Ramp type DVM
4.4
4.1.2
Integrating (Dual slope) type DVM
4.6
4.1.3
Potentiometric type DVM
4.10
4.1.4
Successive approximation type DVM
4.11
4.2
Digital multimeters
4.17
4.3
Automation in voltmeters
4.22
4.3.1
Automatic polarity indication
4.22
4.3.2
Automatic Ranging and Decimal point positioning
4.23
4.3.3
Automatic Zeroing
4.24
4.3.4
Display and Decoders
4.25
4.4
4.5
Accuracy of DVM
4.26
4.4.1
Source of error in d.c voltage measurements
4.28
4.4.2
Source of error in other than d.c voltage ranges
4.30
Guarding Techniques
4.32
4.5.1
Difference between safety guard and signal ground
4.33
4.5.2
Ground loops and ground currents
4.33
4.6
4.7
5.
4.5.3
Common-mode and series-mode voltage
4.34
4.5.4
Protecting the measuring leads from Parastic voltages
4.36
4.5.4.1 Shielding Techniques
4.37
4.5.4.2 Isolation Techniques
4.39
4.5.4.3 Common Mode Rejection ration (CMRR)
4.40
4.5.4.4 Floating guard
4.42
4.5.4.5 Doubly shielded cables
4.43
Frequency Measurements
4.46
4.6.1
Basic circuit
4.46
4.6.2
Time base
4.48
4.6.3
Frequency measurement circuit
4.49
Period measurements
4.50
4.7.1
Single-period measurements
4.51
4.7.2
Multiple-period measurements
4.51
4.7.3
Ratio and multiple ratio measurements
4.53
4.8
Time interval measurements
4.55
4.9
Universal counter timer
4.57
4.10
Plus width measurements
4.58
4.11
Short question & answers
4.60
COMPUTER CONTROLLED TEST SYSTEM
5.1
Introduction
5.1
5.2
Testing an audio amplifier
5.1
5.3
Testing a radio receiver
5.3
5.4
IEEE standard 488 instrument bus
5.4
5.5
Instruments used in computer controlled instrumentation
5.10
5.6
Digital control description
5.14
5.7
Microprocessor based measurements
5.15
5.7.1
Signal transmission in a microprocessor based measurement
5.15
5.7.2
Microprocessor based data logger
5.16
5.8
General outline of instrumentation system in thermal power plants
5.18
5.9
Digital Data Acquistion system
5.25
5.10
Multiplexing
5.27
5.10.1 Frequency division multiplexing
5.27
5.10.2 Time division multiplexing
5.28
Short question and answers
5.29
5.11