Particle Size Calibration Standards - Keeping up with Technology

Quartz reference standards for particle size analysis were produced by the European Community over 20 years ago and coincided with the development of laser diffraction methods of particle size analysis. However, for a number of reasons, some of the early instruments produced equivocal results. These included poor sampling from the large pots, the inhomogeneous optical properties of the quartz and incorrect application of diffraction theory. Existing monodisperse microspheres used in calibrating Coulter Counters produced better results but were not a challenging reference standard because they had such a narrow size distribution.This short review follows the development of particle size reference standards in line with the latest automated particle sizing instruments.