Polarimeters are instruments used for measuring the angle of optical rotation of light. General polarimeters contain mechanisms such as a light source and polarizer.
Light emitted from the light source passes through the polarizer, and the angle of the wave of light is restricted. The angle at which the light rotates is measured when it passes through the substance.

The measurement of optical rotation using a polarimeter is commonplace within the sugar, food, chemical, and pharmaceutical manufacturing industries as production control and quality assurance tool. ATAGO's polarimeter measurement complies with the International Sugar Analysis Unified Committee ICUMSA, which sets the standard for the sugar industry.