本文件通过分析许多两相系统（例如粉末、喷雾、气溶胶、悬浮液、乳液和液体中的气泡）的光散射特性，为仪器鉴定和颗粒尺寸分布测量提供了指南。本标准不涉及特定材料粒度测量的具体要求。 本文件适用于粒径约为0.1μm至3 mm的颗粒。在特殊的仪器和条件下，适用的尺寸范围可以扩展到3mm以上，0.1μm以下。 对于球形和非球形颗粒，报告了尺寸分布，其中球形颗粒体积和的预测散射图案与测量的散射图案匹配。 这是因为该技术在其光学模型中假设了球形粒子形状。对于非球形颗粒，产生的粒径分布不同于基于其他物理原理（例如沉淀、筛分）的方法获得的粒径分布。

This document 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. This document is applicable to particle sizes ranging from approximately 0,1 μm to 3 mm. With special instrumentation and conditions, the applicable size range can be extended above 3 mm and below 0,1 μm. For spherical and 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. For non-spherical particles the resulting particle size distribution is different from that obtained by methods based on other physical principles (e.g. sedimentation, sieving).