Principle and Working :
A polarimeter is an instrument which measures the rotation of the polarisation plane through optically active liquids. It is used to analyse the concentration and contents of substance like sugar solutions. The polarizer produces linear polarised light. This polarised light passes through the half wave plate and then the sample substance. After this it passes through the analyser to the eyepiece. In the eyepiece a triple shadow field can be observed and the angle of rotation is measured with a circular scale and vernier.