Ten of twenty-five stations making up the Regional Air Monitoring System (RAMS) in St. Louis were equipped with dichotomous samplers and high volume filter samplers for aerosol measurements. The dichotomous samplers were designed for automatic operation and were capable of collecting up to 36 samples in each of two size fractions before filter stacks must be changed. Sample filters were pre-weighed by beta gauging before exposure in St. Louis and subsequently returned to LBL for determination of aerosol mass in each size fraction, as well as determination by x-ray fluorescence of the concentrations of the following elements: A, Si, P, C, K, Cr, Mn, Ga, Rb, Sr, Sn, Sb, Ba, Hg, S, Ca, Ti, V, Fe, Ni, Co, Zn, As, Se, Br, Cd, and Pb. Approximately 33,000 samples were collected between March 1975 and March 1977. The operation of the samplers in the RAMS network is described along with problems encountered and procedures used for preventive maintenance and quality control. Also described are two streaker samplers specially installed for continuous aerosol measurements and a silicon cell pyranometer.

"EPA-600/4-79-024"--Cover. "April 1979"--Cover. "Rockwell International Atomics International Division Air Monitoring Center"--T.p. "Contract No. 68-02-2093 Task Order 102"--T.p. "Project officer Stanley Kopczynski"--T.p. "Atmospheric Chemistry and Physics Division Environmental Sciences Research Laboratory"--T.p. Sponsored by U.S. Environmental Protection Agency

Ten of twenty-five stations making up the Regional Air Monitoring System (RAMS) in St. Louis were equipped with dichotomous samplers and high volume filter samplers for aerosol measurements. The dichotomous samplers were designed for automatic operation and were capable of collecting up to 36 samples in each of two size fractions before filter stacks must be changed. Sample filters were pre-weighed by beta gauging before exposure in St. Louis and subsequently returned to LBL for determination of aerosol mass in each size fraction, as well as determination by x-ray fluorescence of the concentrations of the following elements: A, Si, P, C, K, Cr, Mn, Ga, Rb, Sr, Sn, Sb, Ba, Hg, S, Ca, Ti, V, Fe, Ni, Co, Zn, As, Se, Br, Cd, and Pb. Approximately 33,000 samples were collected between March 1975 and March 1977. The operation of the samplers in the RAMS network is described along with problems encountered and procedures used for preventive maintenance and quality control. Also described are two streaker samplers specially installed for continuous aerosol measurements and a silicon cell pyranometer.