ISO 8130-13-2019 pdf free.Coating powders – Part 13: Particle size analysis by laser diffraction. 4 Pnnciple A coating powder sample is analysed by dynamic light scattering. The powder particles scatter hght and their intensities are measured at various angles by a multi array detector to yield a scattering pattern. The pattern is then translonned to numerical values, using an appropriate optical model and mathematical prnedurc, to yield the proportion of the total volume of particles for a discrete number at size classes forming a volumetric particle size distribution (PSI)). 5 Apparatus Ordinary laboratory apparatus, together with the following: 5.1 Laser dllfractlon particle size analyser, as specified in ISO 13320. with a mar range of I im to 300 pm. The instrument should bc located in a clean drait free environment to avoid particulate contamination and be vibration free such that signal to noise ratio is not compromised. More specific guidance Is provided in ISO 13320. The apparatus shall have a feeder suitable for coating powders of different particle shape and a dispersing unit ensuring a constant and agglomerate frcc Ilow of the coating powder For coating powders, compressed air or vacuum is used to disperse the powder particles, and it…