Abstract: Introduced the use of light intensity distribution of test measured the rotation rate of sucrose solution and the concentration method of measurement of light intensity distribution of light intensity tester, using digital galvanometer collect data, and calculate the rotation through the Malus law degrees, and thus sucrose solution derived rotation rate and concentration, details of its measuring principle, and through example to illustrate the measurement method, and shows the experimental results.

Key words: light intensity equipment, specific rotation, polarized light, Malus＇ law