Methods and techniques of measurements are becoming increasingly important in engineering in recent years laboratory programmes have been modernized, sophisticated electronic instrumentation has been incorporated into the programme and newer techniques have been developed. This book dwells on the physical aspects of measurement techniques.? For the measurement to be meaningful, the nature and magnitude of error should be known. The book, thus begins with error analysis and applications of statistical principles to attain a measurement value as near the true value as possible. The methods of measuring mechanical quantities are discussed subsequently, overing both the basic and derived quantities. Effort has been made to present the subject in S.I. units. Some of the recent developments such as laser-doppler techniques, holography, have also been included. The coverage is such that the book will be useful both of graduate and post-graduate students and will also serve as a constant reference for researchers. About The Author R.S. Sirohi?is professor in the department of Physics at the Indian Institute of Technology, Madras. He obtained M.Sc. (Phys.) degree from Agra University, and DIIT (Appl.Opt.) and Ph.D. (Phys.) degrees from Indian Institute of Technology, New Delhi. He was Alexander von Humboldt Fellow at the Physikalisch Technische Bundesanstalt, Braunschweig, Germany. His areas of interest are optical instrumentation, Holography and Speckle phenomenon, measurement and optical testing and laser applications in Optics. He is the author of over 140 research papers in various areas of optics. He has also co-authored two books namely Mechanical Measurements. Wiley Eastern and Optical Components, Systems and Measurement Techniques, Marcel Dekker, Inc. He is the Fellow of Optical Society of America and the Optical Society of India, and a member of many scientific societies. H.C. Radha Krishna?is a professor of Mechanical Engineering, Indian Institute of Technology, Madras. He has varied teaching and research experience in different fields. He has published over 75 papers in National International Journals, Conferences etc. The Institution of Engineers (India) and the Central Board of Irrigation and Power, New Delhi have awarded certificates of merit and Gold Medals for his papers published in their journals. He is a member of the International Editorial Committee Book Series on Hydraulic Machinery, England and Council of International Research Centre for Hydraulic Machinery, Beijing, China. He is a Fellow/Member (life) of many National Professional bodies. Table Of Contents Basic Concepts of Measurements Performance Characteristics of Measuring Instruments Inaccuracy of Measurement and Its Analysis Measurement of Force and Torque Measurement of Strain and Stress Measurement of Pressure Flow Measurement and Flow Visualisation Measurement of Temperature Optical Methods of Measurements Fibre-Optics in Measurement.