EXPERIMENTAL AND THEORETICAL LIGHT-SCATTERING PROFILES FROM SPHERICALAND NONSPHERICAL PARTICLES

A laser light scattering instrument has been designed to allow an inve stigation of the wide angle spatial intensity distribution, or scatter ing profile, of light scattered by individual airborne particles const rained within a laminar how 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 mo nitoring Such as studies of cloud interstitial aerosol or the detectio n of small concentrations of potentially hazardous particles such as r espirable fibers. The instrument has been challenged with both spheric al and nonspherical particle types and appropriate theoretical compari sons have been made with the experimental profiles using either Mie th eory or a simple treatment based on the Rayleigh-Gans formalism. Both experimental and theoretical scattering data are presented, showing go od agreement for all particle types examined.