Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 1978 | public
Journal Article

Design and evaluation of new low-pressure impactor. I

Abstract

An eight-stage, low-pressure impactor is developed with 50% efficiency cutoffs of 4.0, 2.0, 1.0, 0.05, 0.26, 0.11, 0.075, and 0.05-µm aerodynamic diameter. Particles larger than 0.5 µm are sampled at near atmospheric pressure; four stages with stagnation pressures below the jet of 8-140 mm Hg absolute, size segregate the smaller aerosol. The 0.50, 0.26, and 0.11-µm cutoff stages are calibrated with monodisperse polystyrene latex spheres. The final two stages are compared with electrical aerosol analyzer measurements of a laboratory-generated sulfuric acid mist. Studies of impactor collection efficiency show that particle bounce and reentrainment are not important when the collection surfaces are Vaseline coated. The impactor has one jet per stage, and thus is especially suited for aerosol sulfur and nitrate determinations by the method of flash volatilization and subsequent gas-phase analysis.

Additional Information

© 1978 American Chemical Society. Received for review June 3, 1977. Accepted November 30, 1977. Presented at Division of Environmental Chemistry, 173rd Meeting, ACS, New Orleans, La., March 1977. Work supported in part by NIEHS Grant PHS ES 00080-01 and by NSF/RANN Grant ENV76-04179. The Pasadena Lung Association provided funds for instrumentation. The authors thank Patrick Delattre and Peter McMurry for their help.

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023