Mechanical - Metrology and Measurements - Linear and Angular Measurements
Comparators are one form of linear measurement device which is quick and more convenient for checking large number of identical dimensions.
· Least count
The least value that can be measured by using any measuring instrument known as least count. Least count of a mechanical comparator is 0.0 1 mm.
Caliper is an instrument used for measuring distance between or over surfaces comparing dimensions of work pieces with such standards as plug gauges, graduated rules etc.
They are optical instruments used for measuring flatness and determining the length of the slip gauges by direct reference to the wavelength of light.
· Sine bar
Sine bars are always used along with slip gauges as a device for the measurement of angles very precisely.
Auto-collimator is an optical instrument used for the measurement of small angular differences, changes or deflection, plane surface inspection etc.