Mechanical Measurements

S.P. Venkateshan, Professor and Head of Department of Mechanical Engineering, Indian Institute of Technology (IIT) Madras, India. Professor Venkateshan obtained his PhD in 1977 from the Indian Institute of Science, Bangalore, India, specializing in heat transfer. He has been teaching a course in "Measurements in Thermal Engineering" for over 30 years to B.Tech. M.Tech. students, and research scholars pursuing M.S. and Ph. D. degrees. He has developed a web based course and a video lecture series on "Mechanical Measurements" under the NPTEL project of IIT Madras. His research interests are in Radiation Heat Transfer, Free Convection Heat Transfer and Interaction with Radiation, Hydrodynamics Studies in Fluidized Beds, and Heat Transfer with Phase Change.

• Preface viiAcknowledgements xiNomenclature xiiiContents xixI Measurements, Error Analysis and Design of Experiments1 Measurements and Errors in measurement 31.1 Introduction 41.2 Errors in measurement 61.3 Statistical analysis of experimental data 81.4 Propagation of errors 401.5 Specifications of instruments and their performance 442 Regression analysis 472.1 Introduction to regression analysis 482.2 Linear regression 492.3 Polynomial regression 542.4 General non-linear fit 602.5 χ2 test of goodness of fit 622.6 General discussion on regression analysis including special cases 663 Design of experiments 733.1 Design of experiments 74Exercise I 89I.1 Errors and error distributions 89I.2 Propagation of errors 92I.3 Regression analysis 94I.4 Design of experiments 99II Measurements of Temperature, Heat Flux and Heat Transfer Coefficient4 Measurements of Temperature 1034.1 Introduction 1044.2 Thermometry or the science and art of temperature measurement 1044.3 Thermoelectric thermometry 1104.4 Resistance thermometry 1314.5 Pyrometry 1494.6 Other temperature measurement techniques . 1624.7 Measurement of transient temperature . 1715 Systematic errors in temperature measurement 1835.1 Introduction 1835.2 Examples of temperature measurement 1835.3 Conduction error in thermocouple temperature measurement 1865.4 Measurement of temperature of a moving fluid 1946 Heat flux and Heat Transfer Coefficient 2056.1 Measurement of heat flux 2056.2 Measurement of heat transfer coefficient 223Exercise II 229II.1 Temperature measurement 229II.2 Transient temperature measurement 235II.3 Thermometric error 237II.4 Heat flux measurement 239III Measurement of Pressure, Fluid velocity, Volume flow rate, Stagnation and Bulk mean temperatures7 Measurement of Pressure 2437.1 Basics of pressure measurement 2447.2 U - Tube manometer 2457.3 Bourdon gauge 2537.4 Pressure transducers 2547.5 Measurement of pressure transients 2697.6 Measurement of vacuum 2758 Measurement of Fluid Velocity 2818.1 Introduction 2828.2 Pitot - Pitot static and impact probes 2828.3 Velocity measurement based on thermal effects 2938.4 Doppler Velocimeter 3038.5 Time of Flight Velocimeter 3099 Volume flow rate 3159.1 Measurement of volume flow rate 3169.2 Variable area type flow meters 3169.3 Rotameter or Drag effect flow meter 3309.4 Miscellaneous types of flow meters 3349.5 Factors to be considered in the selection of flow meters 3369.6 Calibration of flow meters 33710 Stagnation and Bulk mean temperature 34310.1 Stagnation temperature measurement 34410.2 Bulk mean temperature 346Exercise III 351III.1 Pressure measurement 351III.2 Velocity measurement 353III.3 Volume flow rate 354IV Thermo-physical properties, Radiation properties of surfaces, Gas concentration, Force/Acceleration, torque and power11 Measurement of thermo-physical properties 35911.1 Introduction 36011.2 Thermal conductivity 36011.3 Steady state methods 36111.4 Transient method 36911.5 Measurement of heat capacity 37011.6 Measurement of calorific value of fuels 37411.7 Measurement of viscosity of fluids 38012 Radiation properties of surfaces 38912.1 Introduction 39012.2 Features of radiation measuring instruments 39312.3 Integrating sphere 39412.4 Measurement of emissivity 40013 Gas concentration 40913.1 Introduction 41013.2 Non separation methods 41313.3 Separation methods 41914 Force/Acceleration, torque and power 42914.1 Introduction 43014.2 Force Measurement 43014.3 Measurement of acceleration 43614.4 Measurement of torque and power 448Exercise IV 457IV.1 Thermo-physical properties 457IV.2 Radiation properties of surfaces 459IV.3 Gas concentration 459IV.4 Force, acceleration, Torque and Power 459V Data Manipulation and Examples from laboratory practice15 Data Manipulation 46515.1 Introduction 46615.2 Mechanical signal conditioning 46615.3 Electrical/Electronic signal conditioning 46816 Examples from laboratory practice 48716.1 Introduction 48816.2 Thermocouple calibration using a data logger 48916.3 Calibration of a digital differential pressure gauge 49116.4 Signal conditioning for torque measurement using strain gauges 49216.5 Software 494Exercise V 497A Bibliographic Notes and References 499A.1 Bibliographic Notes 499A.2 References 501B Useful tables 505Index 517