Mechanical Measurements

Preface vii Acknowledgements xi Nomenclature xiii Contents xix I Measurements, Error Analysis and Design of Experiments 1 Measurements and Errors in measurement 3 1.1 Introduction 4 1.2 Errors in measurement 6 1.3 Statistical analysis of experimental data 8 1.4 Propagation of errors 40 1.5 Specifications of instruments and their performance 44 2 Regression analysis 47 2.1 Introduction to regression analysis 48 2.2 Linear regression 49 2.3 Polynomial regression 54 2.4 General non-linear fit 60 2.5 χ2 test of goodness of fit 62 2.6 General discussion on regression analysis including special cases 66 3 Design of experiments 73 3.1 Design of experiments 74 Exercise I 89 I.1 Errors and error distributions 89 I.2 Propagation of errors 92 I.3 Regression analysis 94 I.4 Design of experiments 99 II Measurements of Temperature, Heat Flux and Heat Transfer Coefficient 4 Measurements of Temperature 103 4.1 Introduction 104 4.2 Thermometry or the science and art of temperature measurement 104 4.3 Thermoelectric thermometry 110 4.4 Resistance thermometry 131 4.5 Pyrometry 149 4.6 Other temperature measurement techniques . 162 4.7 Measurement of transient temperature . 171 5 Systematic errors in temperature measurement 183 5.1 Introduction 183 5.2 Examples of temperature measurement 183 5.3 Conduction error in thermocouple temperature measurement 186 5.4 Measurement of temperature of a moving fluid 194 6 Heat flux and Heat Transfer Coefficient 205 6.1 Measurement of heat flux 205 6.2 Measurement of heat transfer coefficient 223 Exercise II 229 II.1 Temperature measurement 229 II.2 Transient temperature measurement 235 II.3 Thermometric error 237 II.4 Heat flux measurement 239 III Measurement of Pressure, Fluid velocity, Volume flow rate, Stagnation and Bulk mean temperatures 7 Measurement of Pressure 243 7.1 Basics of pressure measurement 244 7.2 U - Tube manometer 245 7.3 Bourdon gauge 253 7.4 Pressure transducers 254 7.5 Measurement of pressure transients 269 7.6 Measurement of vacuum 275 8 Measurement of Fluid Velocity 281 8.1 Introduction 282 8.2 Pitot - Pitot static and impact probes 282 8.3 Velocity measurement based on thermal effects 293 8.4 Doppler Velocimeter 303 8.5 Time of Flight Velocimeter 309 9 Volume flow rate 315 9.1 Measurement of volume flow rate 316 9.2 Variable area type flow meters 316 9.3 Rotameter or Drag effect flow meter 330 9.4 Miscellaneous types of flow meters 334 9.5 Factors to be considered in the selection of flow meters 336 9.6 Calibration of flow meters 337 10 Stagnation and Bulk mean temperature 343 10.1 Stagnation temperature measurement 344 10.2 Bulk mean temperature 346 Exercise III 351 III.1 Pressure measurement 351 III.2 Velocity measurement 353 III.3 Volume flow rate 354 IV Thermo-physical properties, Radiation properties of surfaces, Gas concentration, Force/Acceleration, torque and power 11 Measurement of thermo-physical properties 359 11.1 Introduction 360 11.2 Thermal conductivity 360 11.3 Steady state methods 361 11.4 Transient method 369 11.5 Measurement of heat capacity 370 11.6 Measurement of calorific value of fuels 374 11.7 Measurement of viscosity of fluids 380 12 Radiation properties of surfaces 389 12.1 Introduction 390 12.2 Features of radiation measuring instruments 393 12.3 Integrating sphere 394 12.4 Measurement of emissivity 400 13 Gas concentration 409 13.1 Introduction 410 13.2 Non separation methods 413 13.3 Separation methods 419 14 Force/Acceleration, torque and power 429 14.1 Introduction 430 14.2 Force Measurement 430 14.3 Measurement of acceleration 436 14.4 Measurement of torque and power 448 Exercise IV 457 IV.1 Thermo-physical properties 457 IV.2 Radiation properties of surfaces 459 IV.3 Gas concentration 459 IV.4 Force, acceleration, Torque and Power 459 V Data Manipulation and Examples from laboratory practice 15 Data Manipulation 465 15.1 Introduction 466 15.2 Mechanical signal conditioning 466 15.3 Electrical/Electronic signal conditioning 468 16 Examples from laboratory practice 487 16.1 Introduction 488 16.2 Thermocouple calibration using a data logger 489 16.3 Calibration of a digital differential pressure gauge 491 16.4 Signal conditioning for torque measurement using strain gauges 492 16.5 Software 494 Exercise V 497 A Bibliographic Notes and References 499 A.1 Bibliographic Notes 499 A.2 References 501 B Useful tables 505 Index 517