Using ensemble diffraction to measure particle size distribution
A variety of laser-optical techniques can be used to quickly measure particle size distribution. Of these, ensemble diffraction -- which measures several particles at a time rather than one particle -- handles a higher concentration of particles and requires less manipulation of the sample to be measured, increasing the technique's speed and making it especially suitable for in-process analysis. This article provides information on understanding ensemble diffraction, describes how ensemble diffraction is used for laboratory, on-line, and in-process methods of particle size analysis, and explains how to analyze each method's cost-effectiveness.
Several techniques are used to measure particle size, including sieving microscopic examination, sedimentation, centrifugal classification, hydrodynamic chromatography, and zone sensing. Laser-optical techniques are a popular form of zone-sensing that provide fast particle size analysis based on light scattering. Laser-optical techniques use a laser beam and electro-optic photodetector to measure a sample's particle size distribution.