No abstract

The application of the rapid general purpose centrifuge sedimentation method developed at the University of Minnesota to the size analysis of fine powders has been described in a previous publication (2). Through the development of special fine-bore capillary centrifuge tubes, this method has been extended to the size analysis of fractional milligram quantities of airborne dusts collected on 47-mm membrane filters. Evaluation of this method against light and electron microscope data and its extensive use in an airborne dust survey have shown that it is a practical and convenient tool for the size analysis of airborne dusts. Application of this method to the size analysis of airborne dusts and of very fine, dilute suspensions of particles in a liquid is also described.