1.1 这些测试方法涵盖了塑料材料的粒度测量，这些塑料材料通常以粉末、颗粒或颗粒形式提供。由于这些试验方法采用干筛分，测量下限约为38μm（400号筛）。对于较小的颗粒尺寸，建议采用沉降试验方法。 1.2 描述了两种试验方法: 1.2.1 试验方法A- 本试验方法使用选择的多个筛子来测量材料的粒度。该方法用于确定平均粒径和粒径分布。 1.2.2 试验方法B- 本试验方法是使用几个特定筛子进行的试验方法A的缩写版本。本试验方法确定给定筛子上的“通过百分比”或“保留百分比”。试验方法B适用于不具有正常粒径分布的材料，如颗粒和立方体。 1.3 以国际单位制表示的数值应视为金属丝布开口尺寸和金属丝布中所用金属丝直径的标准值。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 注1: 该试验方法没有已知的ISO等效物。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 这些测试方法用于确定粒度分布，因此有助于确定批次间的均匀性。 4.2 塑料材料的粒径会影响处理特性，有时会影响某些聚合物的处理特性。

1.1 These test methods cover the measurement of the particle size of plastic materials in the powdered, granular, or pelleted forms in which they are commonly supplied. As these test methods utilize dry sieving, the lower limit of measurement is considered to be about 38 μm (No. 400 sieve). For smaller particle sizes, sedimentation test methods are recommended. 1.2 Two test methods are described: 1.2.1 Test Method A— This test method uses multiple sieves selected to span the particle size of the material. This method is used to determine the mean particle diameter and particle size distribution. 1.2.2 Test Method B— This test method is an abbreviated version of Test Method A conducted with a few specific sieves. This test method determines “percent passing” or “percent retained” on a given sieve. Test Method B is applicable to materials which do not have a normal particle size distribution such as pellets and cubes. 1.3 The values stated in SI units are to be regarded as standard for dimensions of the wire cloth openings and the diameter of the wires used in the wire cloth. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Note 1: There is no known ISO equivalent for this test method. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 These test methods are used to determine particle size distribution and therefore are useful for determining lot-to-lot uniformity. 4.2 The particle sizes of plastic materials affect the handling characteristics and sometimes will affect the processing characteristics of some polymers.