Citation

Mulholland GW, Liu BYH. J. Res. Natl. Bur. Stand. (1977) 1980; 85(3): 223-238.

Copyright

(Copyright © 1980, U.S. Dept. of Commerce, National Institute of Standards)

DOI

10.6028/jres.085.014

PMID

34566022

Abstract

The response of three light scattering smoke detectors (photo-electric detectors) and three ionization smoke detectors were determined as a function of particle size and concentration for nearly monodisperse dioctyl phthalate aerosol (Og = 1.25). The range in particle diameter was about 25 to I (0.05 to 1.3 "m) while the range in concentration was about two orders of magnitude (2 X 10' to 3 X 10' particles/em'). Detailed descriptions of the aerosol generation system and the smoke detector test chamber are given. The responses of the ionization detectors were found to have a nearly linear dependence on particle size as predicted by Hosemann's theory. The ionization detectors responded to the smallest particles generated. The light scattering detectors did not respond to particles with diameters of O.I"m or less and were found to have a strong dependence on particle size, the fourth to fifth power of particle diameter, for particle sizes less than 0.5"m. It was found that ionization detectors generally had a higher response than the light scattering detectors to particles smaller than 0.3 "m, which size range is typical of flaming combustion, and that the light scattering detectors had a higher response to particles larger than 0.3 "m, which size range is typical of smoldering combustion.

Key words: Aerosol generators; aerosols; detector sensitivity; fire detectors; ionization detectors; light scattering detectors; monodisperse aerosols; particle size; photo-electric detectors; smoke detectors

Language: en

Keywords

Aerosol generators; aerosols; detector sensitivity; fire detectors; ionization detectors; light scattering detectors; monodisperse aerosols; particle size; photo-electric detectors; smoke detectors