1.SINE BAR
*A sine bar consists of a hardened, precision ground body with two precision ground cylinders fixed at the ends. The distance between the centers of the cylinders is precisely controlled, and the top of the baris parallel to a line through the centers of the two rollers.
*Sine bars are always used along with slip gauges as a device for the measurement of angles very precisely.
*They are used to, Measure angles very accurately and locate the work piece to a given angle with very high precision.
2. BEVEL PROTRACTORS
*Bevel protractors are angular measuring instruments.
*The different types of bevel protractors are
i) Vernier Bevel Protractor
ii) Universal Protractor
iii) Optical Protractor
3. AUTOCOLLIMATOR
*Auto-collimator is an optical instrument used for the measurement of small angular differences, changes (or) deflection, plane surface, inspection, etc.,
*For small angular measurements, autocollimator provides a very sensitive and accurate approach.
