SINGLE PARTICLE OPTICAL SIZING(SPOS),A UNIQUE PARTICLE SIZING TOOL FOR POWDERS

Abstract: Most materials are processed in powder form. It has been said that out-of-spec raw materials lead to 60% of the production problems that occur. One important parameter of a raw material powder is the particle size distribution. While many technologies are utilized to determine particle size and particle size distributions,they differ in important characteristics like resolution and sensitivity. While often thought of as a technique used in contamination monitoring, Single Particle Optical Sizing (SPOS) has been used to obtain high resolution particle size distributions. Moreover, the excellent sensitivity of SPOS is used to determine important information about the number and size of out-of-spec particles which may be present in extremely low concentrations (as low as 100 ppb). SPOS utilizes Light Obscuration to determine the particle size distributions of powders in cases of dry sampling and dispersal in liquid. Relevant results will be discussed. The results will be compared to other particle sizing technologies to emphasize cases where high resolution and high sensitivity can be important.