Metrology

Course aims:
The scholars will study
1. Inspection of engineering elements with varied precision devices
2. Design of half, tolerances and matches
3. Rules of measuring devices and gauges and their makes use of
4. Analysis and inspection of floor roughness
5. Inspection of spur gear and thread parts
6. Machine instrument testing to judge machine instrument high quality
UNIT-I
SYSTEMS OF LIMITS AND FITS: Introduction, nominal dimension, tolerance, limits, deviations, matches -Unilateral
and bilateral tolerance system, gap and shaft foundation systems- interchangeability, determistic & statistical
tolerances, selective meeting. Worldwide commonplace system of tolerances, number of limits and tolerances for
right functioning.
UNIT-II
LINEAR MEASUREMENT: Size requirements, finish requirements, slip gauges- calibration of the slip gauges, dial
indicators, micrometers.
MEASUREMENT OF ANGLES AND TAPERS:
Completely different strategies – bevel protractor, angle slip gauges- angle dekkor- spirit levels- sine bar- sine desk, rollers
and spheres used to measure angles and tapers.
LIMIT GAUGES:
Taylor’s precept – design of go and no go gauges; plug, ring, snap, hole, taper, profile and place gauges.
UNIT-III

OPTICAL MEASURING INSTRUMENTS: Instruments maker’s microscope and makes use of – autocollimators, optical
projector, optical flats and their makes use of.
INTERFEROMETRY:
Interference of sunshine, Michelson’s interferometer, NPL flatness interferometer, and NPL gauge interferometer.
UNIT-IV
SURFACE ROUGHNESS MEASUREMENT: Variations between floor roughness and floor waviness –
Numerical evaluation of floor finish-CLA, Rt., R.M.S. Rz, R10 values, Technique of measurement of floor
end – Profilograph, Talysurf, ISI symbols for indication of floor end.
COMPARATORS: Sorts – mechanical, optical , electrical and digital, pneumatic comparators and their
makes use of.

III 12 months – II Semester
L T P C
Four zero zero 3
METROLOGY
UNIT – V
GEAR MEASUREMENT: Nomenclature of substances tooth, tooth thickness measurement with gear tooth vernier &
flange micro meter, pitch measurement, complete composite error and tooth to tooth composite errors, rolling gear
tester, involute profile checking.
SCREW THREAD MEASUREMENT: Parts of measurement – errors in screw threads- idea of digital
efficient diameter, measurement of efficient diameter, angle of thread and thread pitch, and profile thread
gauges.
UNIT – VI
FLATNESS MEASUREMENT:
Measurement of flatness of surfaces- devices used- straight edges- floor plates – auto collimator.
MACHINE TOOL ALIGNMENT TESTS: Rules of machine instrument alignment testing on lathe, drilling and
milling machines.
Textual content Books:
1. Dimensional Metrology/Connie Dotson/Cengage Studying
2. Engineering Metrology / R.Ok.Jain / Khanna Publishers
References:
1. Engineering Metrology / Mahajan / Dhanpat Rai Publishers
2. Engineering Metrology / I.C.Gupta / Dhanpat Rai Publishers
3. Precision Engineering in Manufacturing / R.L.Murthy / New Age
4. Engineering Metrology and Measurements / NV Raghavendra, L Krishna murthy/ Oxford publishers.
5. Engineering Metrology / KL Narayana/Scitech publishers
Course outcomes:
College students will be capable to design tolerances and matches for chosen product high quality. They will select applicable
methodology and devices for inspection of varied gear parts and thread parts. They will perceive the
requirements of size, angles, they will perceive the analysis of floor end and measure the elements with
varied comparators. The standard of the machine instrument with alignment take a look at can be evaluated by them.