Sets out guidance on the measurement of size distributions of particles in any two-phase system, for example powders, sprays, aerosols, suspensions, emulsions and gas bubbles in liquids, through analysis of their angular light scattering patterns. It does not address the specific requirements of particle size measurement of specific products. Applicable to particle sizes ranging from approximately 0.1 µm to 3 mm. This Standard is identical with and has been reproduced from ISO 13320-1:1999.