Apply Now
ELECTRONIC MEASUREMENTS AND INSTRUMENTATION
Contents
Foreword
Preface
Chapter-1 Measurements and instruments
Introduction
Terminology
Advantages of instrumentation systems
Block schematics of measuring systems
Other systems
Objectives of measurement
Comparison between analog and digital instruments
Factors for the selection of analog and digital equipments
Performance characteristics
Definitions
Significant figures
Dynamic characteristics
Types of errors
Gross errors
Systematic errors
Random errors
Statistical analysis
Probability of errors and Gaussian curve
Measurement standards
Suspension galvanometer
D’ Arsonval movement
Taut-band suspension
Temperature compensation
Shunt resistor
Ayrton shunt
Direct current meters
D’ arsonval meter movement used in DC voltmeters
Ammeter loading effect
DC voltmeters
Multirange voltmeter
Ohmmeter
Series-type obmmeter
Shunt-type obmmeter
D’ arsonval meter movement used in obhmmeter
Multiple range obmmeters
Electrolyte capacitor leakage tests
For non-electrolyte capacitors
Multimeter
Alternating current-indicating instruments
Electrodynamometer
Rectifier-type instruments
Meter protection
Extension of range
Frequency compensation
Electronic voltmeter
Electronic voltmeter
Average reading voltmeter
Peak reading voltmeter
Peak-to-peak detector
DC meter with amplifier
Chopper-stabilised amplifier
AC voltmeter using rectifiers
True RMS-responding voltmeter
Balanced bridge voltmeter
Advantages
Disadvantages
Transistor voltmeter
Electronic multimeter
Resistance ranges
AC current measurement
Differential voltmeter
Differential amplifier
Alternating current instruments
D’ arsonval meter movement for AC circuit
Modified circuit for AC measurements
D’arsonval meter movement circuit
Electrodynamometer movement
Transfer instruments
Iron vane-meter movement
Thermocouple meter
Constant voltage source
Constant current source
Volt box
Factors to be considered in the selection of an analog voltmeter
Digital voltmeters
General specifications
Ramp-type DVM
Typical case
Digit display
Pico ammeter
Applications
Low-current ammeter applications
Wafer-level photodiode testing
Monitoring and control of focused ion beam currents
High-resistance measurements
Summary
2 Waveform generators
Introduction
Considerations in choosing an oscillator or signal generator
Sine wave generator
Oscillator circuit
Attenuator
Frequency-synthesized signal generator
Sweep-frequency generator
Pulse and square wave generator
Function generator
Arbitrary waveform generator
Applications
Video signal generator
Summary
3 Signal analysers
Introduction
Wave analyser
AF wave analyser
High-frequency wave analyser
Frequency mixers
Harmonic distortion
Tunable selective circuit
Disadvantages
Heterodyne wave analyser
Fundamental suppression method of distortion measurement
Heterodyne wave analyser
Applications of wave analyser
Tuned circuit harmonic analyser
Heterodyne harmonic analyser or wavemeter
Fundamental suppression harmonic distortion analyser
Spectrum analyser
Characteristics of a spectrum analyser
Applications of a spectrum analyser
Basic spectrum analyser
Factors to be considered in a spectrum analyser
Low-frequency spectrum analyser
Applications
Power analyser
Communications signal analyser
Logic analysers
Network monitoring system
System architecture
Features
Applications
Capacitance-voltage analysers
Oscillators
Considerations in choosing an oscillator
Summary
4 Oscilloscopes
Introduction
Cathode ray oscilloscope
Block diagram of a CRO
Cathode ray tube
Graticules
Electrostatics deflection sensitivity
Design criteria
Different controls in a CRO
How to operate a CRO
Time base generators
Time base circuits
Triggered mode
Free-running mode
Synchronization of the sweep circuit
Types of CROS
Sections of CRTs
Deflection sensitivity equation
Neon time base circuit
Frequency of neon time base
Neon lamp
Free-running mode of CRO
Using CRO in triggered mode
Automode of sweep
Normal mode
Time base circuit for a general-purpose CRO
Synchronization issues
Line synchronization
Lissajous figures
Types of CRO probes
Direct probe
High-impedance probe
Detector probe
High-voltage probe
High-frequency CRO considerations
Delay lines in CROs
Lumped parameter delay line
Distributed parameter delay line
Applications of CRO
Summary
5 Special types of CROs
Special types of oscilloscopes
Dual beam CRO
Dual trace CRO
Sampling oscilloscope
Sampling oscilloscopes-vertical and time base
Sampling vertical
Sampling time base
Storage oscilloscopes
Mesh storage
Variable persistence
Phosphor storage
Phosphor characteristics
Persistence of phosphor materials
CRO subsystems
Digital storage CRO
CRO probes
Frequency/period-timer/counter circuit
Frequency measurement
Period measurement
Advantages
Errors in frequency /period measurements
Errors because of crystal stability
Universal counters
Extending the range of frequency counters
Glossary
The ABC’s of oscilloscopes
Summary
6 DC and AC bridges
Introduction
DC bridges
Wheatstone bridge
Operation
Measurement errors
Thevenin’s equivalent circuit
Kelvin Bridge
Kelvin double bridge
Applications
Strain gauge bridge circuit
Kelvin bridge
Kelvin double bridge
Applications
Strain gauge bridge circuit
AC bridges
General form of bridge circuit
Maxwell bridge
Phasor diagram for the Maxwell bridge
Hay bridge
Phasor diagram for Hay Bridge
Schering Bridge
Phasor diagram for the when bridge
Anderson Bridge
Resonance bridge
Similar Angle Bridge
Radio frequency bridge
Wagner’s ground connection
Twin-T null network
Bridged-T network
Dectectors for AC bridges
Phasor diagrams
Recorders
Introduction
Strip-chart recorders
Galvanometric recorders
Sensitivity
Transient response
Pen-driving mechanism
Other features
Servo recorders
Servo balancing potentiometric recorder
Characteristics of typical servo recorders
Oscillographic recorders
Magnetic type recorders
Direct AM recording
Frequency modulation recording
Recorders
X-Y recorders
Self-balancing potentiometers
Working of a servotype motor
Chopper
Servotype X-Y recorders
Y-scale
Galvanometer oscillographs
Applications
Summary
7 Transducers
Introduction
Examples
Classification of transducers
Active and passive transducers
Factors that affect the performance of a transducer
Applications
Force and displacement transducers
Potentiometer
Potentiometer
Potentiometric transducers
Loading effect on a potentiometer
Resolution
Linear potentiometers
Non-linear potentiometers
Noise
Resistance strain gauges
Bonded-type strain gauges
Filament construction
Materials of the filament wire
Base carrier material
Strain gauge cements
Temperature effect on strain gauges
Measurement of strain
Strain gauge circuitry
The ballast circuit
The wheastone bridges circuit
Circuit for calibration
Mounting of strain gauges
Commercial strain-measuring
8 Other types of transducers
Introduction
Resistance thermometers
Self heating
Advantages of wire resistance thermometers
Disadvantages
Semiconducting-resistance temperature transducers
Circuit employed
Advantages
Disadvantages
Hot wire anemometer
Constant current type
Measurement of direction of average flow
Other variable resistance transducers
Contact pressure transducer
Humidity measurement
Light
Variable inductance transducers
Linear variable differential transformer
Applications of LVDT
LVDT load cells
Synchros
Variable reluctance accelerometer
Microsyn
Temperature measurement
Electric methods
Electrical methods
Thermocouples
Thermocouple junction
Thermocouple insulation
Soldered ,drawn, or rolled sheatched thermocouple construction
Disposable-tip thermocouples
Homogeneity of thermocouple wires
Installation of thermocouples
Cold junction compensation
Resistance thermometry
Platinum resistance thermometers
Special resistance thermometer
Performance and testing procedure
Insulation resistance
Vibration resistance
Thermostors
Thermistor construction techniques
Thermistor performance characteristics
Applications of thermistor
Sensistors
Digital temperature-sensing system
Miscellaneous transducers
Flow measurements
Ultrasonic flow meters
Electromagnetic flow meter
Theory of head flow meters
Various tap connections
Advantages and limitations
Characteristics of head flow meters
Area flow meters
Rotameters
Piston-type area meter
Laser Doppler anemometer
Positive displacement meters
Basic requirement meters
Nutating piston meters
Rotating meters
Oscillating piston meters
Magnetic flow meter
Flow meter requirements
Variable capacitance transducers
Practical capacitor pickups
Feedback-capacitor pickups
Carbon microphone
Circuitry for capacitance transducers
Frequency-modulating oscillator circuit
Circuits using DC excitation
AC bridges for amplitude modulation
Pulse width-modulating circuit
Piezoelectric transducer
Materials
Equivalent circuit
Piezoelectric coefficients
Modes of deformation
Multiple arrangements
Bimorphs
Bimorph twisters
General form of piezoelectric transducers
Available typical piezoelectric transducers
Shock accelerometer
Environmental effects
Magnetostrictive transducers
Magnetostrictive materials
Practical forms of transducers
Magnetostrictive torque transducers
Errors
Temperature
Variation of supply voltage
Eddy currents
Input impedance
Liquid-level measurement
Direct methods
Indirect liquid-level measurement
Capacitance-level gauge
Ultrasonic-level gauge
Measurement of humidity and moisture
Photoconductive cells
Photo pulse pickup
Digital encoders and encoder transducers
Shaft position encoders
Encoder transducers
Fibre optic displacement transducer
Absolute motion devices
Measurement of velocity
Translational velocity transducer moving coil pickup
DC tachometer generators for rotary velocity measurement
AC tachogenerator for rotary velocity measurement
Force measurements
Balance
Elastic force devices
Electromechanical methods
Measurement of pressure
Moderate pressure measurement
Manometers
Elastic transducers
High-pressure measurement
Low-pressure measurement
Thermal conductivity gauge or pirani gauge
Temperature measurements
Data acquisition systems
Summary
Appendix A
Index