JNTUA B.Tech. R20 Regulations

########## JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY ANANTAPUR B.Tech (ME) - III-I Sem L T P C 3 0 0 3 (20A03503T) METROLOGY AND MEASUREMENTS Course Objectives:

- • Introduce the basic concepts of metrology and measurement methods.
- • Demonstrate the importance of metrology in manufacturing
- • Explain the concepts of transducers and its practical applications.
- • Expose with various measuring instruments
- • Familiarize calibration methods of various measuring instruments.

########## Course Outcomes:

- • List various measuring instruments used in metrology.
- • Examine geometry of screw threads and gear profiles.
- • Measure force, torque and pressure.
- • Calibrate various measuring instruments.

UNIT I Concept of measurement General concept-generalized measurement system, units and standards, Concept of Measurement: General concept-generalized measurement system, units and standards, Concept of Measurement: measuring instruments, sensitivity, readability, range of accuracy, precision, static and dynamic response, repeatability, systematic and random errors, correction, calibration, terminology and limits fits and tolerances, hole basis and shaft basis system, interchangeability. Plug, Ring, Snap, Gap, Taper gauges. Taylor's principle. Design of Limit Gauges And Gauge Design: Gauges And Gauge Design: Go and No Go gauges. Linear measuring instruments: Vernier instruments, micrometers, Linear and Angular Measurement: and Angular Measurement: slip gauges, tool makers microscope. Comparators: Mechanical, pneumatic and electrical. Angular Sine bar, bevel protractor and angle dekkor, rollers and spheres used to determine the measurements: tapers.

UNIT - II Flatness and Surface Roughness measurement Measurement of flatness - straight edges - surface plates, optical flat and Flatness Measurement: Measurement of flatness - straight edges - surface plates, optical flat and Flatness Measurement: autocollimators, interferometers and their applications. Terminology systems, differences between surface roughness and Surface Roughness Measurement: Roughness Measurement: surface waviness- Numerical assessment of surface finish - CLA, R.M.S Value-R , R values, Methods a z of measurement of surface finish-profilograph, talysurf, BIS symbols for indication of surface roughness.

UNIT - III Screw Thread and Gear Measurement Elements of threads, errors in screw threads, various methods for Screw thread measurements: Elements of threads, errors in screw threads, various methods for Screw thread measurements: measuring external and internal screw threads, screw thread gauges. Gear tooth terminology, measurement of gear elements-run out, lead, pitch Gear Measurement: Measurement: backlash, profile, pressure angle, tooth thickness, diameter of gear, constant chord and base tangent method.

Coordinate Construction and features. Coordinate Construction and features. Measuring Machine (CMM) UNIT - IV Measurement of Displacement and Strain Theory and construction of various transducers to measure Measurement of Displacement: Theory and construction of various transducers to measure Measurement of Displacement: displacement - Piezo-electric, inductive, capacitance, resistance, ionization and photoelectric transducers, calibration procedures. Various types of electrical strain gauges, gauge factor, method of usage of Measurements of Strain: of Strain: resistance strain gauge for bending, compressive and tensile strains, usage for measuring torque, strain gauge rosettes.