KEY BENEFIT:An up-to-date, practical introduction to engineering experimentation. Introduction to Engineering Experimentation, 3Eintroduces many topics that engineers need to master in order to plan, design, and document a successful experiment or measurement system. The text offers a practical approach with current examples and thorough discussions of key topics, including those often ignored or merely touched upon by other texts, such as modern computerized data acquisition systems, electrical output measuring devices, and in-depth coverage of experimental uncertainty analysis. The book includes theoretical coverage and selected applications of statistics and probability, instrument dynamic response, uncertainty analysis and Fourier analysis; detailed descriptions of computerized data acquisition systems and system components, as well as a wide range of common sensors and measurement systems such as strain gages and thermocouples. Worked examples are provided for theoretical topics and sources of uncertainty are presented for measurement systems. For engineering professionals looking for an up-to-date, practical introduction to the field of engineering experimentation.
Table of Contents
Table of Contents
Previous Edition TOC
CHAPTER 1 Introduction 1
1.1 Applications of Engineering Experimentation and Measurement 1
1.1.1 Measurement in Engineering Experimentation 1
1.1.2 Measurement in Operational Systems 3
1.2 Objective and Overview 3
1.3 Dimensions and Units 3
1.4 Closure 5
CHAPTER 2 General Characteristics of Measurement Systems 6
2.1 Generalized Measurement System 6
2.2 Validity of Measurement 7
2.2.1 Measurement Error and Related Definitions 8
2.2.2 Calibration of Measurement Systems 15
2.3 Dynamic Measurements 23
2.4 Closure 27
References 27
Problems 28
CHAPTER 3 Measurement Systems with Electrical Signals 34
3.1 Electrical Signal Measurement Systems 34
3.2 Signal Conditioners 35
3.2.1 General Characteristics of Signal Amplification 36
3.2.2 Amplifiers Using Operational Amplifiers 42
3.2.3 Signal Attenuation 48
3.2.4 General Aspects of Signal Filtering 50
3.2.5 Butterworth Filters Using Operational Amplifiers 53
3.2.6 Circuits for Integration, Differentiation, and Comparison 57
3.3 Indicating and Recording Devices 58
3.3.1 Digital Voltmeters and Multimeters 58
3.3.2 Oscilloscopes 59
3.3.3 Strip-Chart Recorders 61
3.3.4 Data Acquisition Systems 62
3.4 Electrical Transmission of Signals Between Components 63
3.4.1 Low-Level Analog Voltage Signal Transmission 63
3.4.2 High-Level Analog Voltage Signal Transmission 65
3.4.3 Current-Loop Analog Signal Transmission 66
3.4.4 Digital Signal Transmission 66
References 67
Problems 68
CHAPTER 4 Computerized Data-Acquisition Systems 70
4.1 Introduction 70
4.2 Computer Systems 71
4.2.1 Computer Systems for Data Acquisition 71
4.2.2 Components of Computer Systems 72
4.2.3 Representing Numbers in Computer Systems 74
4.3 Data-Acquisition Components 77
4.3.1 Multiplexers 77
4.3.2 Basics of Analog-to-Digital Converters 78
4.3.3 Practical Analog-to-Digital Converters 85
4.3.4 Digital-to-Analog Converters 88
4.3.5 Simultaneous Sample-and-Hold Subsystems 89
4.4 Configurations of Data-Acquisition Systems 90
4.5 Software for Data-Acquisition Systems 92
4.5.1 Commercial Software Packages 92
References 92
Problems 93
CHAPTER 5 Discrete Sampling and Analysis of Time-Varying Signals 95
5.1 Sampling-Rate Theorem 95
5.2 Spectral Analysis of Time-Varying Signals 100
5.3 Spectral Analysis Using the Fourier Transform 105
5.4 Selecting the Sampling Rate and Filtering 110
5.4.1 Selecting the Sampling Rate 110
5.4.2 Use of Filtering to Limit Sampling Rate 111
References 115
Problems 115
CHAPTER 6 Statistical Analysis of Experimental Data 118
6.1 Introduction 118
6.2 General Concepts and Definitions 120
6.2.1 Definitions 120
6.2.2 Measures of Central Tendency 122
6.2.3 Measures of Dispersion 123
6.3 Probability 124
6.3.1 Probability Distribution Functions 125
6.3.2 Some Probability Distribution Functions
with Engineering Applications 129
6.4 Parameter Estimation 139
6.4.1 Interval Estimation of the Population Mean 140
6.4.2 Interval Estimation of the Population Variance 146
6.5 Criterion for Rejecting Questionable Data Points 149
6.6 Correlation of Experimental Data 151
6.6.1 Correlation Coefficient 151
6.6.2 Least-Squares Linear Fit 155
6.6.3 Outliers in x�y Data Sets 159
6.6.4 Linear Regression Using Data Transformation 163
6.6.5 Multiple and Polynomial Regression 164
6.7 Linear Functions of Random Variables 168
6.8 Applying Computer Software for Statistical Analysis
of Experimental Data 169
References 169
Problems 170
CHAPTER 7 Experimental Uncertainty Analysis 180
7.1 Introduction 180
7.2 Propagation of Uncertainties�General Considerations 180
7.3 Consideration of Systematic and Random Components
of Uncertainty 184
7.4 Sources of Elemental Error 190
7.5 Uncertainty of the Final Results for Multiple-Measurement
Experiments 195
7.6 Uncertainty of the Final Result for Single-Measurement
Experiments 199
7.7 Step-by-Step Procedure for Uncertainty Analysis 202
7.8 Interpreting Manufacturers� Uncertainty Data 203
7.9 Applying Uncertainty Analysis in Digital
Data-Acquisition Systems 204
7.10 Additional Considerations for Single-Measurement
Experiments 208
7.11 Closure 210
References 211
Problems 211
CHAPTER 8 Measurement of Solid-Mechanical Quantities 222
8.1 Measuring Strain 222
8.1.1 Electrical Resistance Strain Gage 222
8.1.2 Strain Gage Signal Conditioning 227
8.2 Measuring Displacement 232
8.2.1 Potentiometer 232
8.2.2 Linear and Rotary Variable Differential Transformers 233
8.2.3 Capacitive Displacement Sensor 237
8.2.4 Digital Encoders 239
8.3 Measuring Linear Velocity 239
8.3.1 Linear Velocity Transducer 239
8.3.2 Doppler Radar Velocity Measurement 240
8.3.3 Velocity Determination Using Displacement
and Acceleration Sensors 241
8.4 Measuring Angular Velocity 242
8.4.1 Electric Generator Tachometers 242
8.4.2 Magnetic Pickup 243
8.4.3 Stroboscopic Tachometer 244
8.4.4 Photoelectric Tachometer 245
8.5 Measuring Acceleration and Vibration 245
8.5.1 Piezoelectric Accelerometers 245
8.5.2 Strain-Gage Accelerometers 248
8.5.3 Servo Accelerometer 249
8.5.4 Vibrometer 249
8.6 Measuring Force 250
8.6.1 Load Cells 250
8.6.2 Proving Rings 252
8.7 Measuring Rotating Shaft Torque 253
References 255
Problems 256
CHAPTER 9 Measuring Pressure, Temperature, and Humidity 261
9.1 Measuring Pressure 261
9.1.1 Traditional Pressure-Measuring Devices 261
9.1.2 Pressure Transducers 268
9.1.3 Measuring a Vacuum 270
9.2 Measuring Temperature 274
9.2.1 Thermocouples 274
9.2.2 Resistance-Temperature Detectors 281
9.2.3 Thermistor and Integrated-Circuit Temperature Sensors 285
9.2.4 Mechanical Temperature-Sensing Devices 286
9.2.5 Pyrometers and Infrared Thermometers 289
9.2.6 Common Temperature-Measurement Errors 293
9.3 Measuring Humidity 298
9.3.1 Hygrometric Devices 299
9.3.2 Dew-Point Devices 299
9.3.3 Psychrometric Devices 299
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9.4 Fiber-Optic Devices 301
9.4.1 Optical Fiber 301
9.4.2 General Characteristics of Fiber-Optic Sensors 303
9.4.3 Fiber-Optic Displacement Sensors 304
9.4.4 Fiber-Optic Temperature Sensors 305
9.4.5 Fiber Optic Pressure Sensors 307
9.4.6 Other Fiber-Optic Sensors 307
References 308
Problems 309
CHAPTER 10 Measuring Fluid Flow Rate, Fluid Velocity, Fluid Level,
and Combustion Pollutants 313
10.1 Systems for Measuring Fluid Flow Rate 313
10.1.1 Pressure Differential Devices 313
10.1.2 Variable-Area Flowmeters 329
10.1.3 Turbine Flowmeters 332
10.1.4 Mass Flowmeters 333
10.1.5 Positive-Displacement Flowmeters 336
10.1.6 Other Methods of Flow Measurement 336
10.1.7 Calibrating Flowmeters 340
10.2 Systems for Measuring Fluid Velocity 341
10.2.1 Pitot-Static Probe 341
10.2.2 Hot-Wire and Hot-Film Anemometers 343
10.2.3 Fluid Velocity Measurement Using the
Laser-Doppler Effect 345
10.3 Measuring Fluid Level 347
10.3.1 Buoyancy Devices 348
10.3.2 Differential-Pressure Devices 349
10.3.3 Capacitance Devices 350
10.3.4 Conductance Devices 351
10.3.5 Ultrasonic Devices 351
10.3.6 Weight Methods 352
10.4 Measuring Air Pollution Species 352
10.4.1 Nondispersive Infrared Detectors 353
10.4.2 Chemiluminescent Analyzers 354
10.4.3 Flame Ionization Detectors 355
10.4.4 Other Gas-Analysis Devices 356
10.4.5 General Considerations about Sampling and
Measuring Pollutant Gases 357
References 358
Problems 359
CHAPTER 11 Dynamic Behavior of Measurement Systems 363
11.1 Order of a Dynamic Measurement System 363
11.2 Zero-Order Measurement Systems 364
11.3 First-Order Measurement Systems 364
11.3.1 Basic Equations 365
11.3.2 Step Input 365
11.3.3 Ramp Input 366
11.3.4 Sinusoidal Input 368
11.3.5 Thermocouple as a First-Order System 368
11.4 Second-Order Measurement Systems 373
11.4.1 Basic Equations 373
11.4.2 Step Input 374
11.4.3 Sinusoidal Input 376
11.4.4 Force Transducer (Load Cell) as a Second-Order System 377
11.4.5 Pressure-Measurement Devices as Second-Order Systems 380
11.4.6 Second-Order Systems for Acceleration and Vibration 388
11.5 Closure 393
References 394
Problems 394
CHAPTER 12 Guidelines for Planning and Documenting Experiments 397
12.1 Overview of an Experimental Program 397
12.1.1 Problem Definition 397
12.1.2 Experiment Design 398
12.1.3 Experiment Construction and Development 398
12.1.4 Data Gathering 399
12.1.5 Data Analysis 399
12.1.6 Interpreting Data and Reporting 399
12.2 Common Activities in Experimental Projects 399
12.2.1 Dimensional Analysis and Determining
the Test Rig Scale 399
12.2.2 Uncertainty Analysis 403
12.2.3 Shakedown Tests 403
12.2.4 Test Matrix and Test Sequence 404
12.2.5 Scheduling and Cost Estimation 408
12.2.6 Design Review 412
12.2.7 Documenting Experimental Activities 413
12.3 Closure 421
References 421
Answers to Selected Problems 422
APPENDIX A Computational Methods for Chapter 5 425
APPENDIX B Selected Properties of Substances 429
Glossary 434
Index
