Abstract

A laser polar nephelometer (Grams et al, 1975) has been used to measure the light scattered in two polarization planes by monodisperse non-spherical particles at scattering angles between 10 and 170° in 5° steps. The monodisperse aerosols were generated in the laboratory with a vibrating orifice particle generator (TSI model 53050) using solutions of non-absorbing salts such as sodium chloride, ammonium sulfate and potassium chlorate and of absorbing compounds such as nigrosine dye and methylene blue. Samples of the aerosols were collected onto filters during the measurements for subsequent analyses on a scanning electron microscope. In our experiments, the particle sizes ranged from 1 to 4 μm, corresponding to a range of values of the Mie size parameter from 5 to 20 at the wavelength of the laser (λ=633 nm).