The instrument consists of two - round scales. One with index and the other with venire. The first scale (index scale) is for tuning the analyzer into the azimuth. The Second scale (Venire 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)