An electrical aerosol analyzer capable of performing rapid, in situ size distribution measurement on aerosols from 0.003 to 1 μm diameter has been described. The instrument is based on the “diffusion charging-mobility analysis” principle first described by Whitby and Clark. The prototype instrument has a total volume of 3.75 ft3 and a total weight of 60 lb, and is sufficiently portable to be used on small airplanes and ground based vehicles for mobile air pollution studies. The paper describes the design, operation, and performance of the instrument. Sample data are presented showing the size distributions of aerosols measured by the instrument on board a small research aircraft over the Los Angeles basin at several different altitudes. In addition, data are presented showing the size distribution of smog chamber aerosols and aerosols produced by a conventional Collison atomizer.
Bibliographical noteFunding Information:
The aerosol charger used in the instru ment was developed for the aerosol charging studies supported by the AEC Contract (11-1)-1248; the remainder of the instrument was developed under the EPA Grant 801175; the aircraft and smog chamber studies were supported by the EPA Grant R800971. We also wish to thank Frank Dorman for his assistance in developing the electronics used in the instrument.