Experimental and theoretical light scattering profiles from spherical and non-spherical particles

Abstract

A laser light scattering instrument has been designed to allow an investigation of the wide angle spatial intensity distribution, or scattering profile, of light scattered by individual airborne particles constrained within a laminar flow sample airstream, with a view to providing a means of classifying the particles in terms of their shape and size. Such an instrument may find application in areas of environmental monitoring such as studies of cloud interstitial aerosol or the detection of small concentrations of potentially hazardous particles such as respirable fibers. The instrument has been challenged with both spherical and nonspherical particle types and appropriate theoretical comparisons have been made with the experimental profiles using either Mie theory or a simple treatment based on the Rayleigh-Gans formalism. Both experimental and theoretical scattering data are presented, showing good agreement for all particle types examined.