Universal refractometer after Abbe

Description

The instrument is built on a black enamelled cast iron foot with a pillar. The pillar ends in a ring on which the various parts of the instrument are mounted. Below is a flat, rectangular mirror and the block with the two prisms. The block with the prisms swivels together with the arm carrying the microscope that is used for reading the refractive index scale. A small amount of the liquid to be tested is inserted between the prisms, the block can be heated or cooled by water, there is a thermometer to read the temperature.
The part of the instrument carrying the refractive index scale is connected to the limb carrying the two Amici prisms, these are adjusted in such a way that a clear light/dark image is formed.
If its desirable to measure the refractive index of a piece of glass a flat face has to be ground first, this is then used instead of the lower prism.
The refractometer was used in dairy farming to measure the fat content of butter.

Also see SM 103, SM 202 and SM 252.