The
instrument consists of two - round scales. One with index and the other with
vernier. The first scale (index scale) is for tuning the analyser into the
azimuth. The Second scale (Vernier Scale) is for measuring the degree of
orientation of a wedge box.
The Wedge Box contains
two wedges cut in mutually perpendicular direction of optics axis in quartz.
The long wedge is movable by means of a micrometer drum, with the help of which
accurate reading of the movement is taken. Micrometer screw minimum reading
0.001cm. (i.e. Least count)
