Rapid particle sizing by photosedimentometry

Abstract

An instrument is described which sizes particles in the range from 2-200 micrometres ( mu m). The instrument is inexpensive and uses the well established technique of photosedimentation, where Stoke's law is applied to the case of laminar flow settling, and extended into the region of transitional flow settling. The analysis time is typically less than 10 minutes. Additional information such as specific surface area and the calculation of particle shape factor can be obtained from the analysis. Comparisons are made between commercially available instruments and a prototype photosedimentometer.