scope:

This ISO standard provides guidance on instrument qualification and size distribution measurement of particles in many two-phase systems (e.g. powders, sprays, aerosols, suspensions, emulsions and gas bubbles in liquids) through the analysis of their light scattering properties. It does not address the specific requirements of particle size measurement of specific materials. ISO 13320 is applicable to particle sizes ranging from approximately 0,1 ìm to 3 mm. With special instrumentation and conditions the applicable size range can be extended above 3 mm. Some advance is also noted for particles smaller than 0,1 ìm. For non-spherical particles a size distribution is reported, where the predicted scattering pattern for the volumetric sum of spherical particles matches the measured scattering pattern. This is because the technique assumes a spherical particle shape in its optical model. The resulting particle size distribution will be different from those obtained by methods based on other physical principles (e.g. sedimentation, sieving).