Light scattering aerosol measurements for absorbing particles

A discussion based on exact Mie theory calculations is given on light scattering aerosol measurements for absorbing aerosol particles. From the calculations of Mie's scattering light intensity functions for absorbing particles as a variable of imaginary part of refractive index, it has been found that the scattering light intensities vary abruptly with the variance of imaginary parts in the region from 0 to 0.2 of their value. Response calculations for the aerosol particle photocounter for particle sizing and the aerosol photometer for particle concentration measurement have been made for absorbing particles. As a result, it is pointed out that one should take into account the absorbing properties of aerosol particles on the light scattering aerosol measurement, particularly when the particle size is greater than 1 μm. (auth.)