Polarimeters are optical instruments utilizing so called polarized light. There are a great number of organic and inorganic substances being “optically active” in their liquid or dissolved state.
Such substances are able to rotate the direction of oscillation of polarized light around a determined angle. This angle of rotation is measured by a polarimeter with highest precision. Thus, a polarimeter will be used to determine the concentration of the optical active substance which is dissolved in an optically inactive liquid.