Unit 1
Concept of Metrology: Definition and concept of Metrology – need of Inspection – Generalized measurement system – Units and standards – measuring instruments; sensitivity, stability, range, accuracy and precision, static and dynamic response, repeatability – systematic and random errors – correction; calibration.
Linear Measurements: Vernier-caliper, Vernier depth gauge, Micrometer, Depth micrometer, Digital micrometer. Slip gauges: wringing of slip gauges and classification – Tool maker’s microscope. Dial indicators – classification and working mechanism. Limit gauges; Comparators: Mechanical, pneumatic and electrical types, applications – Height Gauge, Bore Gauge and Feeler Gauge.
Angular Measurements: Uses of the Vernier Bevel protractor, Universal Bevel protractor and Optical Bevel protractor. Sine bars – Uses and limitations of sine bar – Taper measurements. Sources of errors in sine bars, Sine Centre and Sine tables – Auto collimator and its applications.