DEPARTMENT OF MECHANICAL ENGINEERING MEASUREMENT AND METROLOGY BY

� DEPARTMENT OF MECHANICAL ENGINEERING � MEASUREMENT AND METROLOGY � � BY: -SUNIL PATIDAR ASST. PROF(ME DEPT. )

INTRODUCTION TO MEASUREMENT AND METROLOGY

What is Measurement � � What is Measurement The act or process of measuring something a size or length or anything id defined as Measurement.

OBJECTIVES � � 1. Design of equipment and processes 2. Properation control and maintenance of processes 3. For evaluating the performance of a system 4. To test the functioning of components

TYPES OF MEASUREMENTS � � � � 1. Linear Measurement 2. Angular and Taper Measurement 3. Screw Thread Measurement 4. Gear Measurement 5. Surface Finish Measurement 6. Temperature Measurement 7. Pressure Measurement 8. Miscellaneous Measurement

Instrumentation and Different Characteristics of Measurement � Instrumentation : It is the technology of making measurement and in which the instruments are used for sensing, measurement, control and monitoring the physical and chemical properties of material.

CHARACTERISTICS : � � � Static Characteristics : Error Accuracy Calibration Hysteresis Dead Zone Drift Sensitivity Threshold Resolution Precision

DYNAMIC CHARACTERISTICS � � � � Speed of response Measuring lag Fidelity Dynamic error Overshoot Dead time and dead zone Frequency response

ERRORS AND THEIR CLASSIFICATION � � � � � Errors : The error in measurement is the difference between the measured value and the true value of the measured dimension. Reasons : 1. Manufacturing error in instrument. 2. Defective instruments. 3. Environmental effect (temperature, humidity, etc) 4. Human errors (observation, adjustment, etc. ) 5. Manual adjustment of an instrument.

CLASSIFICATION OF ERRORS � � � Gross errors or mistakes : Blunders Computational errors Chaotic errors Systematic errors : Instrument errors Environment errors Observation errors Operational errors System interaction errors Random errors

METROLOGY , TYPES AND ITS OBJECTIVES Metrology : It is the science of measurement. � Types Of Metrology : Industrial metrology Medical metrology �

OBJECTIVES 1. To minimize the cost of inspection by efficient and effective use of available facilities. 2. To minimize the cost of rejection and re- work through application of statistical quality control techniques. 3. To maintain the accuracies of measurement. 4. To determine the process capabilities and ensure that these are better than the relevant component tolerances. 5. To do complete evaluation of newly developed products. 6. To standardize the measuring methods. �

STANDARDS OF MEASUREMENT Primary Standards : They are the material standards preserved under most careful conditions. These are not used directly for measurements but are used once in 10 or 20 years for calibrating secondary standards. Ex: International Prototype meter , Imperial Standard yard �

STANDARDS OF MEASUREMENT � Secondary Standards: These are the close copies of primary standards with respect to design, material and length. Any error existing in this standards is recorded by comparison with primary standards after long intervals. They are kept at a number of places under great supervision and serve as reference for tertiary standards. This also acts as safeguard against the loss or destruction of primary standards.