The minnesota aerosol-analyzing system used in the Los Angeles smog project

The Los Angeles Smog Project, a collaborative research effort involving investigators from the University of Minnesota, California Institute of Technology, California State Department of Health, University of Washington, and the California Statewide Air Pollution Research Center, has been described. The project includes an intensive 4-week experiment period from August 19 to September 19, 1969 during which various physical and chemical parameters of the aerosol were measured. A summary description of the project, including its genesis, objectives, and scope has been given in this paper. The Minnesota Aerosol Analyzing System used in the Los Angeles Smog Project has been described. The instrument system, consisting of three aerosol sensors in parallel operation, was used to measure the aerosol size distribution from 0. 0035 to 6. 8 μm diameter automatically; and the data were recorded directly on punched tape for computer processing. The sensors used include a Condensation Nucleus Counter, a Whitby Aerosol Analyzer, and an optical particle counter. Characteristics of the sensors, methods of calibration, and estimates of accuracies have been given.