"RAC" to measure the constants of elliptical polarisation and double refraction due to strain in transparent media.
The compensator consists of two wedges of quartz, one fixed with optic axis in one direction while the other moving with optic axis in a perpendicular direction. The movable wedge is moved by means of a micrometer screw with a readable accuracy of .005 mm. The total movement of the same is 20 mm. The wedge system fixed in a box which is and integral part, can be rotated in a circular scale with least count 1/10 degree, fine and coarse movements are provided The analyser has an independent scale which can be arranged in any angular position with respect to wedges. The fringe width is 6 mm. Complete in cabinet.