A Polarimeter (manual version)

A Polarimeter is used to measure the angle of rotation caused by optically active substances, such as a sugar solution.

A yellow LED (585nm) in the base shines through a polarising film, through the sample in the tube, then through another polarising film in the cap.

First the user rotates the cap until the light they see through the cap is the darkest. Then the scale is rotated to match the 0 with the pointer on the cap. Next the sample is placed in a 16mm diameter test tube and put in t