Brochure: Particle Size Analysis

Accurately determining particle size has become essential in many industries, as it is a fundamental physical characteristic that must be selected, monitored, and controlled from the raw material source to the finished product. There is an optimum particle size, or at least a smallest and largest acceptable size, for most items involving particles. The key to accurate particle size determination is selecting the most appropriate sizing instrument for a particular application. This is not a simple undertaking.

If all particles were spheres, their size would be defined explicitly by their diameter or radius; if cubical, the length along one edge would be characteristic; and, if of other regular shape, another equally appropriate dimension could be chosen. Unfortunately the great majority of particles are quite irregular and an arbitrary definition of size is the only simple solution. Moreover, typical collections of particles include many different sizes and shapes. Thus, a definition is required that accommodates this diversity, and the ‘equivalent spherical diameter (or radius)' satisfies this requirement.