The detection angle choice in characterization of aerosols and hydrosols by LDA

Abstract

The light scattering on spherical particles and factors influencing the choice of the optimum detection angle in the LDA system are analyzed in this paper. The analysis using the Lorenz-Mie theory is made. The intensity and the phase angular distribution of light scattered on a spherical particle depend on its diameter and relative refraction index of the particle and surrounding material. The distribution function shape, and therefore the optimum detection angle, change rapidly with the change of the particle diameter. However, in real measurements, there is always not only one size of the scattering spheres, but the range of sizes – polydisperse case. The expected mean diameter and the width of the size range of scattering particles are also taken into account in our optimum detecting angle calculations. The results calculations are shown graphically and some conclusions are stated.