Note for Metrology and Measurements - MM by Abhishek Apoorv

Topics ( 6 )

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FMCET Department of MECH UNIT-I CONCEPTS OF MEASUREMENT UNIT-I 1. 1

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MADHAN KUMAR.P FMCET Department of MECH CONTENTS 1.1 1.2 GENERAL CONCEPT 1.1.1 Introduction to Metrology 1.1.2 Introduction to Measurement 1.1.3 Types of Metrology OBJECTIVES OF METROLOGY 1.2.1 Necessity and Importance of Metrology 1.3 METHODS OF MEASUREMENTS 1.4 GENERALIZED MEASUREMENT SYSTEM 1.5 1.6 1.7 UNIT-I 1.4.1 Units 1.4.2 Standards 1.4.3 Classification of Standards 1.4.4 Accuracy of Measurements 1.4.5 Precision 1.4.6 Accuracy 1.4.7 Distinction between Precision and Accuracy 1.4.8 Factors affecting the accuracy of the measuring system SENSITIVITY 1.5.1 Readability 1.5.2 Calibration 1.5.3 Repeatability 1.5.4 Reproducibility STATIC AND DYNAMIC RESPONSE 1.6.1 Zero-Order Instrument 1.6.2 First-Order Instrument 1.6.3 Second-Order Instrument ERRORS IN MEASUREMENTS 1.7.1 Absolute Error 1.7.2 Types of Errors 1. 2

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MADHAN KUMAR.P FMCET Department of MECH 1.8 INTRODUCTION TO DIMENSIONAL AND GEOMETRIC TOLERANCE 1.9 INTERCHANGEABILITY UNIT-I 1. 3

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MADHAN KUMAR.P FMCET Department of MECH TECHNICAL TERMS Measurement Measurement is the act, or the result, of a quantitative comparison between a predetermined standard and an unknown magnitude. Range It represents the highest possible value that can be measured by an instrument. Scale sensitivity It is defined as the ratio of a change in scale reading to the corresponding change in pointer deflection. It actually denotes the smallest change in the measured variable to which an instrument responds. True or actual value It is the actual magnitude of a signal input to a measuring system which can only be approached and never evaluated. Accuracy It is defined as the closeness with which the reading approaches an accepted standard value or true value. Precision It is the degree of reproducibility among several independent measurements of the same true value under specified conditions. It is usually expressed in terms of deviation in measurement. Repeatability UNIT-I 1. 4