The Small Universal Polarimeter is a visual circle polarimeter with a circular scale of ±180° angular degrees divided into full degrees. Together with the Vernier scale rotations can be measured to an accuracy of 0.1° and with a little practice they can be estimated to an accuracy of 0.05°.

Two possible lighting units are existing. The less expensive halogen lamp unit for instructional purposes – it has a longer life and is ready for use immediately upon switching on – or the spectral lamp unit for higher absolute accuracy.

Halogen lamps produce white light, and an interference filter is required to produce the monochromatic light of the desired wavelength. The filter is inserted into the light admission opening of the polarizer. In this way measurements can be made at different wavelengths without time-consuming alterations to the apparatus (the halogen lamp does not need to be changed). A transformer is needed to connect the unit to the normal mains supply.

A sodium spectral lamp emits light of a defined wavelength (line spectrum). In order to block out undesired side spectral lines, coloured glass filter should be used. It also must be inserted into the light admission opening. To connect the spectral lamp lighting unit to the mains, a current limiting ballast unit should be used.