Measurement of particle sizes by higher order tyndall spectra (θ 1 method)

Abstract

Particle size measurements by higher order Tyndall spectra have been developed. In a previous experiment it was found that the first angle, θ 1, which is measured from the direction of propagation of the incident beam, of red spectra of higher order Tyndall spectra is related to the average particle size, r (1). These relations have been discussed from the theoretical standpoint. The average radius of a monodisperse aerosol consisting of spherical particles can be evaluated by measuring θ 1 from the following equation independent of refractive index except for the value of 2.0:log ( θ 10 ) + 1.43 log (10r̄) = 1.43, where θ 1 is in degrees of angle and r in microns.