An instrument which is suitable for investigating the light scattering properties of macromolecules in solution in the angular range 20° to 160° is described. A null modulation method is used to measure the ratio of the intensity Iθ of the light scattered at an angle θ to the direction of the incident light to that (I0) incident on the scattering volume. This is accomplished by attenuating I0 until it equals Iθ, this condition being found by an electronic detector. The value of Iθ is known from a calibration experiment. Details are given of the optical arrangement, the detector, and the calibration and method of use of the apparatus. Adequate sensitivity, accuracy, and stability are demonstrated.
H. G. Jerrard and D. B. Sellen, "A New Apparatus for Light Scattering Studies," Appl. Opt. 1, 243-247 (1962)