Chapter 1 Applications of Electronic Instrument Systems

1.1 Introduction

1.2 The Electronic Instrument System

1.3 Engineering Analysis

1.4 Process Control

1.4.1 Process Control Devices

1.5 Experimental Error

1.5.1 Accumulation of Accepted Error

1.5.2 Improper Functioning of Instruments

1.5.3 Effect of the Transducer on the Process

1.5.4 Dual Sensitivity Errors

1.5.5 Other Sources of Error

1.6 Minimizing Experimental Error

1.7 Summary

References

Exercises

Chapter 2 Analysis of Circuits

2.1 Introduction and Definitions

2.2 Basic Electrical Components

2.3 Kirchhoff’s Circuit Laws

2.4 Diodes, Transistors, and Gates

2.4.1 Diodes

2.4.2 Transistors

2.4.3 Gates

2.5 DC Circuits

2.6 Periodic Functions

2.7 AC Circuits

2.7.1 Impedance

2.8 Frequency Response Function

2.9 Summary

References

Exercises

Chapter 3 Analog Recording Instruments

3.1 Introduction

3.2 General Characteristics of Recording Instruments

3.3 Voltmeters for Steady-State Measurements

3.3.1 D’arsonval Galvanometer

3.3.2 Ammeter

3.3.3 DC Voltmeters

3.3.4 Voltmeter Loading Errors

3.3.5 Amplified Voltmeters

3.3.6 Potentiometric Voltmeters

3.4 Voltmeters for Slowly Varying Signals

3.4.1 Strip-Chart Recorders

3.4.2 X-Y Recorders

3.5 Voltmeters for Rapidly Varying Signals

3.5.1 Oscillograph Recorders

3.5.2 Transient Response of Galvanometers

3.5.3 Periodic Signal Response of Galvanometers

3.5.4 Oscilloscopes

3.5.5 Magnetic Tape Recorders

3.6 Summary

References

Exercises

Chapter 4 Digital Recording Systems

4.1 Introduction

4.2 Digital Codes

4.3 Conversion Processes

4.4 Digital-to-Analog Converters

4.5 Analog-to-Digital Converters

4.5.1 Successive-Approximation Method

4.5.2 Intergration Method

4.5.3 Parallel or Flash Method

4.6 Data Distribution

4.6.1 Bus Structures

4.7 Interfaces

4.8 Digital Voltmeters

4.9 Data-Logging Systems

4.10 Data-Acquisition Systems

4.11 PC-Based Data-Acquisition Systems

4.12 Digital Oscilloscopes

4.13 Waveform Recorders

4.14 Aliasing

4.14.1 Antialiasing Filters

4.15 Summary

References

Exercises

Chapter 5 Sensors for Transducers

5.1 Introduction

5.2 Potentiometers

5.3 Differential Transformers

5.4 Resistance Strain Gages

5.5 Capacitance Sensors

5.6 Eddy-Current Sensors

5.7 Piezoelectric Sensors

5.8 Piezoresistive Sensors

5.9 Photoelectric Sensors

5.9.1 Vacuum-Tube Detectors

5.9.2 Photoconductive Cells

5.9.3 Semiconductor Photodiodes

5.10 Resistance Temperature Detectors

5.11 Thermistors

5.12 Thermocouples

5.13 Crystal Oscillators

5.14 Summary

References

Exercises

Chapter 6 Signal Conditioning Circuits

6.1 Introduction

6.2 Power Supplies

6.2.1 Battery Supplies

6.2.2 Line Voltage Supplies

6.3 Potentiometer Circuit (Constant Voltage)

6.4 Potentiometer Circuit (Constant Current)

6.5 Wheatstone Bridge (Constant Voltage)

6.6 Wheatstone Bridge (Constant Current)

6.7 Amplifiers

6.8 Operational Amplifiers

6.8.1 Inverting Amplifier

6.8.2 Differential Amplifier

6.8.3 Voltage Follower

6.8.4 Summing Amplifier

6.8.5 Integrating Amplifier

6.8.6 Differentiating Amplifier

6.9 Filters

6.9.1 High-Pass RC Filter

6.9.2 Low-Pass RC Filter

6.9.3 Active Filter

6.10 Amplitude Modulation and Demodulation

6.11 Time-Measuring Circuits

6.11.1 Binary Counting Unit

6.11.2 Gates in Counter Applications

6.11.3 Triggers

6.11.4 Counting Instruments

6.12 Summary

References

Exercises

Chapter 7 Resistance-Type Strain Gages

7.1 Introduction

7.2 Etched-Foil Strain Gages

7.3 Strain-Gage Installation

7.4 Wheatstone Bridge Signal Conditioning

7.5 Recording Instruments for Strain Gages

7.5.1 Direct-Reading Strain Indicator

7.5.2 Null-Balance Bridges

7.5.3 Strain-Gage Signal Conditioners

7.5.4 Wheatstone Bridge and Oscilloscope

7.5.5 Wheatstone Bridge and Oscillograph

7.6 Calibration Methods

7.7 Effects of Lead Wires, Switches, and Slip Rings

7.7.1 Lead Wires

7.7.2 Switches

7.7.3 Slip Rings

7.8 Electrical Noise

7.9 Temperature-Compensated Gages

7.10 Alloy Sensitivity, Gage Factor, and Cross-Sensitivity Factors

7.11 Data-Reduction Methods

7.11.1 The Uniaxial State of Stress

7.11.2 The Biaxial State of Stress

7.11.3 The General State of Stress

7.12 High-Temperature Strain Measurements

7.13 Summary

References

Exercises

Chapter 8 Force, Torque, and Pressure Measurements

8.1 Introduction

8.2 Force Measurements (Load Cells)

8.2.1 Link-Type Load Cell

8.2.2 Beam-Type Load Cell

8.2.3 Ring-Type Load Cell

8.2.4 Shear-Web-Type Load Cell

8.3 Torque Measurement (Torque Cells)

8.3.1 Torque Cells—Design Concepts

8.3.2 Torque Cells—Data Transmission

8.4 Combined Measurements of Force and Moments or Torques

8.4.1 Force-Moment Measurements

8.4.2 Force-Torque Measurements

8.5 Pressure Measurements (Pressure Transducers)

8.5.1 Displacement-Type Pressure Transducer

8.5.2 Diaphragm-Type Pressure Transducer

8.5.3 Piezoelectric-Type Pressure Transducer

8.6 Minimizing Errors in Transducers

8.6.1 Dual Sensitivity

8.6.2 Zero Shift with Temperature Change

8.6.3 Bridge Balance

8.6.4 Span Adjust

8.6.5 Span Change with Temperature

8.7 Frequency Response of Transducers

8.7.1 Response of a Force Transducer to a Terminated Ramp Function

8.7.2 Response of a Force Transducer to a Sinusoidal Forcing Function

8.8 Calibration of Transducers

8.9 Summary

References

Exercises

Chapter 9 Displacement, Velocity, and Acceleration Measurements

9.1 Introduction

9.2 The Seismic Transducer Model

9.3 Dynamic Response of the Seismic Model

9.3.1 Sinusoidal Excitation

9.3.2 Transient Excitations

9.4 Seismic Motion Transducers

9.4.1 Seismic Displacement Transducers

9.4.2 Seismic Velocity Transducers

9.4.3 Seismic Acceleration Transducers

9.5 Piezoelectric Force Transducers

9.6 Piezoelectric Sensor Circuits

9.6.1 Charge Sensitivity Model

9.6.2 Voltage-Follower Circuit

9.6.3 Charge-Amplifier Circuit

9.6.4 Built-in Voltage Followers

9.7 Response of Piezoelectric Circuits to Transient Signals

9.8 Accelerometer Calibration

9.9 Dynamic Calibration of Force Transducers

9.9.1 Force Transducer Calibration by Impact

9.10 Overall System Calibration

9.11 Sources of Error with Piezoelectric Transducers

9.12 Displacement Measurements in a Fixed Reference Frame

9.12.1 Displacement Measurements with Resistance Potentiometers

9.12.2 Displacement Measurements with Multiple-Resistor Devices

9.12.3 Photoelectric Displacement Transducers

9.13 Optical Displacement Measurements

9.13.1 Optical Tracker System

9.13.2 Video Camera Motion Analysis

9.14 Velocity Measurements

9.14.1 Linear-Velocity Measurements

9.14.2 Angular-Velocity Measurements

9.14.3 Laser-Doppler System

9.15 Summary

References

Exercises

Chapter 10 Analysis of Vibrating Systems

10.1 Introduction

10.1.1 Temporal Mean

10.1.2 Temporal Mean Square and Root Mean Square

10.2 Sinusoidal Signal Analysis

10.3 Characteristics of Signals

10.3.1 Periodic Signals

10.3.2 Transient Signals

10.3.3 Random Signals

10.4 Lumped Mass-Spring Vibration Models

10.4.1 Undamped Natural Frequency and Mode Shape

10.4.2 Forced Vibration Response (Direct Solution)

10.4.3 Forced Vibration Response (Modal Solution)

10.5 Continuous Vibration Models

10.5.1 Fundamental Equation of Motion

10.5.2 Steady-State Modal Solution

10.6 The Linear Input-Output Model

10.6.1 Impulse Response

10.6.2 Random Input-Output Relationships

10.7 Basics of a Digital Frequency Analyzer

10.7.1 Time Sampling Process

10.7.2 Convolution

10.7.3 Filter Leakage

10.7.4 Block Diagram

10.8 Using a Digital Frequency Analyzer

10.8.1 Relationships for Frequency Analyzers

10.8.2 Filter Characteristics

10.8.3 Four Common Window Functions

10.8.4 Uncertainty in the Magnitude of Spectral Lines

10.8.5 Summary of Window Use

10.9 Accelerometer Cross-Axis Sensitivity

10.9.1 Single Accelerometer Cross-Axis Coupling Model

10.9.2 Triaxial Accelerometer Model

10.9.3 Correcting Acceleration Voltage Readings

10.9.4 Application to Modal Analysis Signals

10.9.5 Cross-Axis Resonance

10.10 Force Transducer-Structure Interaction

10.10.1 General Two-Degree-of-Freedom Force Transducer Model

10.11 Summary

References

Exercises

Chapter 11 Temperature Measurements

11.1 Introduction

11.2 Expansion Methods for Measuring Temperature

11.3 Resistance Thermometers

11.3.1 Resistance Temperature Detectors (RTDS)

11.3.2 RTDS and the Wheatstone Bridge

11.3.3 Thermistors

11.4 Thermocouples

11.4.1 Principles of Thermocouple Behavior

11.4.2 Thermoelectric Materials

11.4.3 Reference Junction Temperature

11.4.4 Fabrication and Installation Procedures

11.4.5 Recording Instruments for Thermocouples

11.4.6 Noise Suppression in Thermocouple Circuits

11.5 Integrated-Circuit Temperature Sensors

11.6 Dynamic Response of Temperature Sensors

11.7 Sources of Error in Temperature Measurements

11.8 Calibration Methods

11.9 Radiation Methods (Pyrometry)

11.9.1 Principles of Radiation

11.9.2 The Optical Pyrometer

11.9.3 Infrared Pyrometers

11.9.4 Photon Detector Temperature Instruments

11.10 Summary

References

Exercises

Chapter 12 Fluid Flow Measurements

12.1 Introduction

12.2 Flow Velocity (Insertion-Type Transducers)

12.2.1 Pitot Tube (Incompressible Flow)

12.2.2 Pitot Tube (Compressible Flow)

12.2.3 Hot-Wire and Hot-Film Anemometers

12.2.4 Drag-Force Velocity Transducers

12.2.5 Current Meters

12.2.6 Turbine Flow Meters

12.2.7 Vortex-Shedding Transducers

12.3 Flow Rates in Closed Systems by Pressure-Variation Measurements

12.3.1 Venturi Meter

12.3.2 Flow Nozzle

12.3.3 Orifice Meter

12.3.4 Elbow Meter

12.4 Flow Rates in Partially Closed Systems

12.5 Flow Rates in Open Channels from Pressure Measurements

12.5.1 Sluice Gate

12.5.2 Weirs

12.6 Compressible Flow Effects in Closed Systems

12.7 Other Flow-Measurement Methods for Closed Systems

12.7.1 Capillary Flow Meter

12.7.2 Positive-Displacement Flow Meters

12.7.3 Hot-Film Mass Flow Transducers

12.7.4 Laser Velocimetry Systems

12.8 Summary

References

Exercises

Chapter 13 Statistical Methods

13.1 Introduction

13.2 Characterizing Statistical Distributions

13.2.1 Graphic Representations of the Distribution

13.2.2 Measures of Central Tendency

13.2.3 Measures of Dispersion

13.3 Statistical Distribution Functions

13.3.1 Gaussian Distribution

13.3.2 Weibull Distribution

13.4 Confidence Intervals for Predictions

13.5 Comparision of Means

13.6 Statistical Conditioning of Data

13.7 Regression Analysis

13.7.1 Linear Regression Analysis

13.7.2 Multivariate Regression

13.8 Chi-Square Testing

13.9 Error Accumulation and Propagation

13.10 Summary

References

Exercises

Appendix A

Appendix B

Author Index

Subject Index