18AU35 Mechanical Measurement and Metrology syllabus for AU

Measurements, Measurement Systems and Standards of Measurement:

Definition, significance of measurement, generalized measurement system, definition and concept of accuracy, precision, sensitivity, Calibration, threshold, hysteresis, repeatability, linearity, loading effect, system response, time delay, errors in measurement, classification of errors. Definition and objectives of metrology, Standard of length- International prototype meter, Imperial standard yard, Wave length standard, Subdivision of standards, line and end standard, comparison, Transfer from line standard to end standard, calibration of end bars (Numerical)

Comparators:

Introduction to Comparator, Characteristics, Classification of Comparators, Sigma comparators, dial indicators, optical comparators, principles, ziess ultra optimeter, Electric and electronic comparators –principles, LVDT, pneumatic comparators, back pressure gauges, solex comparators.

Angular Measurementsand Interferometer:

Bevel protractor. Sine principle, use of sine bars, sine centre, angle gauges (numerical on building of angles), Clinometers. Principle of inter-ferometry, autocollimator, optical flats.

Transducers, Intermediate Modifying and Display Devices:

Transfer efficiency, primary and secondary transducers, Mechanical, electrical transducers (resistive capacitive and piezoelectric transducers), electronic transducers, advantages of each type of transducers. Mechanical systems, inherent problems, electrical intermediate modifying devices, input circuitry, mechanical signal transmission, . Mechanical, digital read out devices, ultra-violet recorders, servo-recorders cathode ray oscilloscope, Oscillographs, X-Y plotters

Measurement of Force,Torque and strain :

Principle, analytical balance, platform balance proving ring, torque measurement, types of dynamometers prony brake, Hydraulic dynamometer, Eddy current dynamometer. Strain gauge, preparation and mounting of strain gauges, gauge factor, Methods of strain measurement.

System of Limits, Fits, Tolerance and Gauging:

Definition of tolerance, Specification in assembly, Principle of interchangeability and selective assembly, limits of size, Indian standards, concept of limits of size and tolerances, definition of fits, hole basis system, shaft basis system, types of fits and their designation (IS 919- 1963), geometric tolerance, position-tolerances.

Pressure and Temperature Measurement:

Principle, use of elastic members, bridge man gauge, Mcleod gauge, thermal conductivity gauge, (pirani gauge and thermocouple vacuum gauge) ionization gauge, Resistance thermometers, thermocouple, law of thermocouple, thermocouple circuits, thermocouple materials, pyrometers, optical pyrometer.

Course Outcomes:

At the end of the course the student will be able to:

• explain significance of mechanical measurements, elements of a generalized measuring system, theory and working principle of measuring instruments for the measurement of force, torque, flow, temperature, pressure and strain.
• Define Metrology, appreciate the objectives of Metrology, and explain the importance of standards.
• Interpret the limits specified, identify fits and explain the concept of tolerance.
• Use comparators, screw and gear metrology

Question paper pattern:

• The question paper will have ten full questions carrying equal marks.
• Each full question will be for 20 marks.
• There will be two full questions (with a maximum of four sub- questions) from each module.
• Each full question will have sub- question covering all the topics under a module.
• The students will have to answer five full questions, selecting one full question from each module.

Textbook/s

1 Engineering Metrology. R. K. Jain Khanna Publishers, New Delhi 2007

2 Mechanical Measurements and Control D. S. Kumar Metropolitan Book Co. Pvt. Ltd, New Delhi 2005

Reference Books

3 Hand book of Industrial Metrology ASTME PHI 4th edition

4 Engineering Metrology K. J. Hume Kalyani publishers Third (metric) Edition