Study of the use of cascade impactors for analyzing airborne particles of high specific gravity

Abstract

The need for full utilization of cascade-impactor data from a recent weapons test series led to a study of impactor use for characterizing airborne particulate matter of high specific gravity. As a part of the study, the Andersen and Casella cascade impactors used during the test series were calibrated with spherical particles ranging in specific gravity from 1 to 22. A source genera tor was developed which created aluminum, nickel, gold, and platinum spheres. A very direct method was developed to determine impactor stage efficiencies from experimental data. Application of the impact parameter concept to material of high specific gravity was demonstrated. The use of cascade impactors for studying airborne particles as well as for determining human respiratory uptake was evaluated. This dissertation summarizes the theoretical and experimental findings on the calibration of cascade impactors and on the utilization of cascade-impactor data.