The following instrument is essentially used as a comparator and measures the changes in angular position of the reflector in two planes?

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JKSSB JE Mechanical 02 Nov 2021 Shift 1 Official Paper

Answer 1

Explanation:

An Angle Dekkor is a small variation of the autocollimator.

This instrument is essentially used as a comparator and measures the change in angular position of the reflector in two planes.

Working and application:

F1 S.S N.J 18-07-19 D 8

It has an illuminated scale, which receives light directed through a prism
The light beam carrying the image of the illuminated scale passes through the collimating lens as shown in figure and falls onto the reflecting surface of the workpiece
After getting reflected from the workpiece, it is refocused by the lens in field view of the eyepiece
It has a wide range of applications, as angular variations can be directly read through the eyepiece of the instrument

Some of the typical applications are

Measurement of sloping angle of V-blocks
Calibration of taper gauges
Measurement of angles of conical parts
Determination of a precise angular setting for machining operations etc; for example, milling a slot at some precise angle to a previously machined datum surface