Measurements of sizes of submicron particles by a method of scattering light

It is often necessary to measure the size of small particles. For this purpose, optical methods are used much oftener. These methods employ the fact that the shape of scattering indicatrix and intensity of scattered light depend on the size of these particles and the wavelength of incident radiation. There are two techniques of measuring: 1) At the fixed wavelength, the intensity of scattered light is measured in several directions; 2) The intensity of light scattered in a given direction is measured at several wavelengths. A method of determining the mean size of nonabsorbing particles, which is based on the second technique, is widely used