Citation

Handa T, Suda K, Nagashima T, Kaneko K, Yamamura T, Takahashi Y, Suzuki H. Fire Safety J. 1978; 1(4-5): 255-263.

Copyright

(Copyright © 1978, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

A handy and transportable submicron level optical counter was developed for the in situ measurement of aerosol systems even at high concentrations. The counter has a low output He---Ne laser light source (unpolarized, 8 mW), a sideways light scattering system at right angles with a solid angle of light collection of 0.5 steradian, and a 9-channel counting system which can cover the particle size range from 0.07 [mu]m to more than 10 [mu]m at m = 1.60. A high concentration measurement can be achieved up to 1 x 1013 particulates/m3 on the basis of an equation derived for the first order correction of the coincidence loss and cross-channel sensitivity due to the counting loss, while the critical concentration of the instrument with a low coincidence loss can ordinarily reach 5 x 1010 particulates/m3. When applied to the measurement of polypropylene smoke, a good coincidence was obtained between the scattering cross-sections from the observed turbidities and those calculated from the size distribution after the correction of the coincidence loss etc. On this basis, the turbidities of several smokes and their stepwise coagulation are characterized by the change in their size distributions.