Babinet Compensator 

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 azymuth . T h e Second scale ( Vernier Scale)isformeasuring the degree of orientaon of awedge box. The Wedge Box contains two wedges cut in mutually perpendicular direcon of opcs 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)