Some aspects of light scattering from polydisperse systems of spherical particles

The simple theory of light scattering, as developed by Debye, is discussed and its application to polydisperse systems of spherical particles examined. Three measurements are possible, namely, dissymmetry, turbidity and the relation of the latter with wavelength. By employing model distributions these three parameters of the scattering may be calculated and the average values for the diameter given by them studied. The dissymmetry ratio, whilst giving an indeterminate average, leads to values of the diameters which approximate to the weight average given by the turbidity technique. The wavelength dependence of turbidity gives a diameter which approximates to the mean of the distribution.