An Experimental Research On Particles Size And Concentration Based On The Light Scattering

In this thesis, the method for measuring particles size distribution and concentration by using light scattering is introduced. The Mie theory of light scattering by particles is given. The approximate approaches of Rayleigh and Fraunhofer diffraction are discussed for smaller and larger particles. Based on the light scattering theory, we use three-wave methods to obtain the mean diameter of the particles. By using the optimization algorithm, the particles size distribution is calculated based on the dependent model algorithm. Two results are agreed well. We describe in detail the expression of particles size distribution. The expression of volume concentration and mean particle size is deduced based on the diffraction scattering method. An experiment is designed and built up. We obtain the sample particles size distribution, peak value, mean size and volume concentration by experimental measurement. Compared to the theoretical results, the experimental result shows that the method used is high in precision, repetition and reliability.