Contents
Preface to the Third Edition
List of Abbreviations
List of Important Formulae
xix
xxiii
xxvi
1.
Qualities of Measurements
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
1.12
Introduction 1
Performance Characteristics 1
Static Characteristics 2
Error in Measurement 2
Types of Static Error 5
Sources of Error 8
Dynamic Characteristics 8
Statistical Analysis 11
Standard 15
Electrical Standards 16
Atomic Frequency and Time Standards 19
Graphical Representation of Measurements as a Distribution 20
Review Questions 22
Multiple Choice Questions 23
Practice Problems 24
Further Reading 24
2.
Indicators and Display Devices
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
Introduction 25
Basic Meter Movement 26
Taut Band Instrument 31
Electrodynamometer 32
Moving Iron Types Instrument 35
Concentric Vane Repulsion Type (Moving Iron Type) Instrument 36
Digital Display System and Indicators 38
Classification of Displays 38
Display Devices 39
Light Emitting Diodes (LED) 39
Liquid Crystal Display (LCD) 41
25
viii Contents
2.12
2.13
2.14
2.15
2.16
2.17
2.18
2.19
2.20
2.21
Other Displays 43
Printers 54
Classification of Printers 54
Printer Character Set 55
Character at a Time Impact Printers for Fully Formed
Characters (Drum Wheel) 55
Line at a Time Impact Printers for Fully Formed
Characters (Line Printers) 57
Drum Printer 58
Dot-Matrix Printers 59
Character at a Time Dot-Matrix Impact Printer 59
Non-Impact Dot-Matrix (NIDM) Printers 61
Review Questions 61
Multiple Choice Questions 63
Further Reading 63
3.
Ammeters
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
DC Ammeter 64
Multirange Ammeters 66
The Aryton Shunt or Universal Shunt 67
Requirements of a Shunt 71
Extending of Ammeter Ranges 71
RF Ammeter (Thermocouple) 72
Limitations of Thermocouples 73
Effect of Frequency on Calibration 74
Measurements of Very Large Currents by Thermocouples 75
Review Questions 76
Multiple Choice Questions 77
Practice Problems 77
Further Reading 78
4.
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
Voltmeters and Multimeters
Introduction 79
Basic Meter as a DC Voltmeter 79
DC Voltmeter 80
Multirange Voltmeter 81
Extending Voltmeter Ranges 84
Loading 87
Transistor Voltmeter (TVM) 91
Chopper Type DC Amplifier Voltmeter (Microvoltmeter) 92
Solid State Voltmeter 95
Differential Voltmeter 96
DC Standard/Difference Voltmeter 96
AC Voltmeter Using Rectifiers 99
64
79
Contents ix
4.13
4.14
4.15
4.16
4.17
4.18
4.19
4.20
4.21
4.22
4.23
4.24
4.25
4.26
AC Voltmeter Using Half Wave Rectifier 100
AC Voltmeter Using Full Wave Rectifier 101
Multirange AC Voltmeter 104
Average Responding Voltmeter 105
Peak Responding Voltmeter 106
True RMS Voltmeter 107
True RMS Meter 107
Considerations in Choosing an Analog Voltmeter 109
Ohmmeter (Series Type Ohmmeter) 110
Shunt Type Ohmmeter 117
Calibration of DC Instrument 120
Calibration of Ohmmeter 120
Multimeter 121
Multimeter Operating Instructions 123
Review Questions 124
Multiple Choice Questions 125
Practice Problems 126
Further Reading 127
5.
Digital Voltmeters
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
5.11
Introduction 128
Ramp Technique 129
Dual Slope Integrating Type DVM (Voltage to Time Conversion) 130
Integrating Type DVM (Voltage to Frequency Conversion) 132
Most Commonly Used Principles of ADC (Analog to
Digital Conversion) 135
Successive Approximations 136
Continuous Balance DVM or Servo Balancing
Potentiometer Type DVM 140
3½-Digit 140
Resolution and Sensitivity of Digital Meters 141
General Specifications of a DVM 142
Microprocessor-Based Ramp Type DVM 142
Review Questions 145
Multiple Choice Questions 145
Practice Problems 146
Further Reading 146
6.
Digital Instruments
6.1
6.2
6.3
6.4
6.5
Introduction 147
Digital Multimeters 148
Digital Frequency Meter 152
Digital Measurement of Time 155
Universal Counter 158
128
147
x Contents
6.6
6.7
6.8
6.9
6.10
6.11
6.12
6.13
6.14
6.15
Decade Counter 159
Electronic Counter 160
Digital Measurement of Frequency (Mains) 162
Digital Tachometer 165
Digital pH Meter 165
Automation in Digital Instruments 166
Digital Phase Meter 171
Digital Capacitance Meter 172
Microprocessor-Based Instruments 173
The IEEE 488 Bus 173
Review Questions 174
Multiple Choice Questions 175
Further Reading 175
7.
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
7.11
7.12
7.13
7.14
7.15
7.16
7.17
7.18
7.19
7.20
7.21
7.22
7.23
7.24
7.25
7.26
7.27
7.28
7.29
Oscilloscope
Introduction 176
Basic Principle 176
CRT Features 180
Block Diagram of Oscilloscope 184
Simple CRO 185
Vertical Amplifier 186
Horizontal Deflecting System 187
Triggered Sweep CRO 188
Trigger Pulse Circuit 189
Delay Line in Triggered Sweep 190
Sync Selector for Continuous Sweep CRO 191
Typical CRT Connections 191
High Frequency CRT or Travelling Wave Type CRT 192
Dual Beam CRO 193
Dual Trace Oscilloscope 194
Electronic Switch 200
(VHF) Sampling Oscilloscope 201
Storage Oscilloscope (For VLF Signal) 202
Digital Readout Oscilloscope 204
Measurement of Frequency by Lissajous Method 206
Spot Wheel Method 208
Gear Wheel Method 209
Checking of Diodes 211
Basic Measurement of Capacitance and Inductance 211
Oscilloscope as a Bridge Null Detector 213
Use of Lissajous Figures for Phase Measurement 214
Standard Specifications of a Single Beam CRO 216
Probes for CRO 217
Attenuators 220
176
Contents xi
7.30
7.31
7.32
7.33
7.34
7.35
Applications of Oscilloscope 222
Delayed Sweep 223
Digital Storage Oscilloscope (DSO) 224
Fibre Optic CRT Recording Oscilloscope 226
Oscilloscope Operating Precautions 228
Placing an Oscilloscope in Operation 229
Review Questions 230
Multiple Choice Questions 231
Practice Problems 232
Further Reading 232
8.
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
8.10
8.11
8.12
8.13
8.14
8.15
8.16
8.17
8.18
8.19
8.20
Signal Generators
9.
9.1
9.2
9.3
9.4
9.5
9.6
9.7
Wave Analyzers and Harmonic Distortion
233
Introduction 233
Fixed Frequency AF Oscillator 234
Variable AF Oscillator 234
Basic Standard Signal Generator (Sine Wave) 235
Standard Signal Generator 235
Modern Laboratory Signal Generator 236
AF Sine and Square Wave Generator 238
Function Generator 239
Square and Pulse Generator (Laboratory Type) 240
Random Noise Generator 242
Sweep Generator 243
TV Sweep Generator 244
Marker Generator 245
Sweep-Marker Generator 247
Wobbluscope 247
Video Pattern Generator 247
Colour Bar Generator 249
Vectroscope 253
Beat Frequency Oscillator (BFO) 255
Standard Specifications of a Signal Generator 256
Review Questions 257
Multiple Choice Questions 258
Further Reading 259
Introduction 260
Basic Wave Analyzer 261
Frequency Selective Wave Analyzer 262
Heterodyne Wave Analyzer 263
Harmonic Distortion Analyzer 265
Spectrum Analyzer 267
Digital Fourier Analyzer 269
260
xii Contents
9.8
Practical FFT Spectrum Analysis Using a Waveform Processing
Software (Ss-36) 273
Review Questions 276
Multiple Choice Questions 277
Further Reading 277
10.
10.1
10.2
10.3
10.4
10.5
10.6
10.7
10.8
10.9
10.10
10.11
10.12
10.13
10.14
Measuring Instruments
11.
Bridges
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
11.9
11.10
11.11
11.12
11.13
11.14
11.15
11.16
11.17
Introduction 322
Wheatstone’s Bridge (Measurement of Resistance) 322
Kelvin’s Bridge 328
Practical Kelvin’s Double Bridge 331
Bridge Controlled Circuits 332
Digital Readout Bridges 334
Microprocessor Controlled Bridges 335
AC Bridges 336
Capacitance Comparison Bridge 337
Inductance Comparison Bridge 339
Maxwell’s Bridge 340
Hay’s Bridge 342
Schering’s Bridge 345
Wien’s Bridge 351
Wagner’s Earth (Ground) Connection 354
Resonance Bridge 355
Maxwell–Wien Bridge 3356
278
Introduction 278
Output Power Meters 278
Field Strength Meter 279
Stroboscope 280
Phase Meter 281
Vector Impedance Meter (Direct Reading) 283
Q Meter 286
LCR Bridge 295
RX Meters 303
Automatic Bridges 304
Transistor Tester 305
Megger 310
Analog pH Meter 311
Telemetry 315
Review Questions 319
Multiple Choice Questions 320
Practice Problems 321
Further Reading 321
322
Contents xiii
11.18
11.19
11.20
11.21
11.22
11.23
Anderson Bridge 358
The Owen Bridge 359
De Sauty Bridge 360
Carey Foster / Heydweiller Bridge 361
Types of Detectors 363
Precautions to be Taken When Using a Bridge 363
Review Questions 364
Multiple Choice Questions 365
Practice Problems 366
Further Reading 369
12.
12.1
12.2
12.3
12.4
12.5
12.6
12.7
12.8
12.9
12.10
12.11
12.12
12.13
12.14
12.15
Recorders
13.
Transducers
13.1
13.2
13.3
13.4
13.5
13.6
13.7
13.8
13.9
13.10
13.11
Introduction 406
Electrical Transducer 406
Selecting a Transducer 408
Resistive Transducer 408
Resistive Position Transducer 411
Strain Gauges 413
Resistance Thermometer 423
Thermistor 425
Inductive Transducer 428
Differential Output Transducers 432
Linear Variable Differential Transducer (LVDT) 433
370
Introduction 370
Strip Chart Recorder 371
Galvanometer Type Recorder 374
Null Type Recorder (Potentiometric Recorders) 376
Circular Chart Recorder 381
X–Y Recorder 382
Magnetic Recorders 385
Frequency Modulation (FM) Recording 388
Digital Data Recording 390
Objectives and Requirements of Recording Data 392
Recorder Selections for Particular Applications 393
Recorder Specifications 393
Potentiometric Recorder (Multipoint) 394
Digital Memory Waveform Recorder (DWR) 399
Applications of a Strip Chart Recorder 401
Review Questions 403
Multiple Choice Questions 404
Practice Problems 405
Further Reading 405
406
xiv Contents
13.12
13.13
13.14
13.15
13.16
13.17
13.18
13.19
13.20
13.21
13.22
13.23
13.24
13.25
13.26
13.27
Pressure Inductive Transducer 440
Capacitive Transducer (Pressure) 446
Load Cell (Pressure Cell) 448
Piezo Electrical Transducer 449
Photo Electric Transducer 451
Photo-Voltaic Cell 454
Semiconductor Photo Diode 454
The Photo-Transistor 455
Temperature Transducers 456
Frequency Generating Transducer 479
Reluctance Pulse Pick-Ups 479
Flow Measurement (Mechanical Transducers) 479
Mechanical Flow Meter 480
Magnetic Flow Meters 480
Turbine Flowmeter 483
Measurements of Thickness Using Beta Gauge 484
Review Questions 488
Multiple Choice Questions 491
Further Reading 492
14.
14.1
14.2
14.3
14.4
14.5
14.6
Signal Conditioning
15.
15.1
15.2
15.3
15.4
15.5
15.6
15.7
15.8
15.9
15.10
15.11
15.12
15.13
Filters
493
Introduction 493
Operational Amplifier (OPAMP) 497
Basic Instrumentation Amplifier 511
Applications of Instrumentation Amplifiers (Specific Bridge) 518
Chopped and Modulated DC Amplifier 521
Modulators 522
Review Questions 530
Further Reading 531
Introduction 532
Fundamental Theorem of Filters 532
Passive Filters 536
Active Filters 540
Butterworth Filter 544
Band Pass Filter 554
Band Reject (Stop) Filter 562
All Pass Filter 564
Universal Active Filters 566
Designing Procedures for FLT-U2 568
Types of Active Filters 572
Digital Filters 574
Discrete Functions 575
532
Contents xv
15.14
15.15
15.16
15.17
15.18
15.19
15.20
15.21
15.22
15.23
15.24
15.25
The 1-D Sampling Theorem 576
The 2-D Sampling Theorem 576
The 1-D Z-Transform 576
Fundamental Properties of 1-D Digital Systems 577
Fundamental Property of 2-D Digital Systems 578
Frequency Domain Representation 578
Fir 1-D Digital Filter Design (The Window Method) 583
Design Methods for IIR Digital Filters 585
1-D IIR Filter Design 587
Program for the Design of Butterworth and Chebyschev IIR
Digital Filters by Means of the Bilinear Transformation 591
Microprocessor Based Digital Filter 595
Applications of Digital Filters 596
Review Questions 600
Multiple Choice Questions 603
Practice Problems 604
Further Reading 604
16.
16.1
16.2
16.3
16.4
16.5
16.6
16.7
16.8
16.9
16.10
16.11
16.12
16.13
Measurement Set-up
17.
17.1
17.2
17.3
17.4
17.5
17.6
Data Acquisition System (DAS)
605
Introduction 605
Measurements of Microwave Frequencies 605
Resonant Co-Axial Lines 606
Cavity Wavemeters 607
RF/UHF Field Strength Meter (Methods for Measuring
the Strength of Radio Waves) 607
Measurement of Sensitivity 608
Measurement of Selectivity 609
Intermodulation Method of Measuring Non-Linear Distortion 610
Measuring Frequency Response in Audio Amplifiers 614
Modulation 615
Measuring Frequency Modulation 618
Measuring Frequency Deviation with a Radio Receiver 618
Measuring Amplitude Modulation Using CRO 619
Review Questions 623
Multiple Choice Questions 624
Further Reading 625
Introduction 626
Objective of a DAS 628
Signal Conditioning of the Inputs 628
Single Channel Data Acquisition System 630
Multi-Channel DAS 632
Computer Based DAS 636
626
xvi Contents
17.7
17.8
17.9
17.10
17.11
Digital to Analog (D/A) and Analog to Digital (A/D) Converters 637
Data Loggers 653
Sensors Based Computer Data Systems 663
Electromechanical A/D Converter 671
Digital Transducer 673
Review Questions 675
Multiple Choice Questions 677
Practice Problems 678
Further Reading 679
18.
Data Transmission
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
Introduction 680
Data Transmission Systems 682
Advantages and Disadvantages of Digital Transmission
Over Analog 682
Time Division Multiplexing (TDM) 684
Pulse Modulation 686
Digital Modulation 695
Pulse Code Format 704
Modems 706
Review Questions 710
Multiple Choice Questions 711
Further Reading 712
19.
Frequency Standards
19.1
19.2
19.3
19.4
19.5
19.6
19.7
Introduction 713
Primary Standards 713
Secondary Standards of Frequency 714
Practical Frequency Standards 714
Radio Signals as Frequency Standards 715
Precision Frequency Standards 715
The Atomic Clock 716
Review Questions 717
Multiple Choice Questions 717
Further Reading 717
20.
Measurement of Power
20.1
20.2
20.3
20.4
20.5
20.6
20.7
Introduction 718
Requirements of a Dummy Load 718
Bolometer 718
Bolometer Method of Power Measurement 719
Bolometer Element 719
Bolometer Mount 720
Measurement of Power by Means of a Bolometer Bridge 720
680
713
718
Contents xvii
20.8
20.9
20.10
20.11
20.12
20.13
Unbalanced Bolometer Bridge 722
Self Balancing Bolometer Bridge 723
Measurement of Large Amount of RF Power
(Calorimetric Method) 724
Measurement of Power on a Transmission Line 726
Standing Wave Ratio Measurements 727
Measurement of Standing Wave Ratio Using
Directional Couplers 728
Review Questions 731
Multiple Choice Questions 732
Practice Problems 732
Further Reading 732
21.
21.1
21.2
21.3
21.4
21.5
21.6
21.7
21.8
21.9
21.10
21.11
21.12
21.13
21.14
21.15
21.16
Control Systems
733
Basic Control Action 733
Definition (Terminology) 734
On–Off Control Action 736
Proportional Control Action 738
Offset 739
Basic Controller Configuration 739
Classification of Controllers 740
Electronic Controllers (EC) 740
Analog Electronic Process Controllers 741
Temperature Control using an Analog Electronic Controller 745
Choice of Electronic Transmission Signal 747
Digital Controllers 748
Digital Process Controller 750
Cascade Process Controller with Digital Controllers 751
Programmable Logic Controller 752
Distributed Control Systems 796
Review Questions 815
Further Reading 816
Answers to Objective Type Questions
Index
817
820