1.1 这些测试方法包括测量通常供应的粉末、颗粒或颗粒形式的塑料材料的粒度。由于这些测试方法利用干式筛分，因此认为测量下限约为38μm（400号筛）。对于较小的粒径，建议采用沉降试验方法。 1.2 描述了两种测试方法: 1.2.1 试验方法A— 该测试方法使用选择用于跨越材料粒度的多个筛子。该方法用于测定平均粒径和粒度分布。 1.2.2 试验方法B— 该测试方法是使用一些特定筛子进行的测试方法A的缩写版本。该测试方法确定给定筛子上的“合格率”或“保留率”。测试方法B适用于不具有正常粒度分布的材料，例如颗粒和立方体。 1.3 以国际单位制表示的数值应被视为线布开口尺寸和线布中使用的线材直径的标准。 1.4 本标准无意解决与其使用相关的所有安全问题（如果有的话）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定法规限制的适用性。 附注1: 该测试方法没有已知的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》中确立的国际公认的标准化原则制定的。= 意义和用途 ===== 4.1 将塑料材料的干燥块放置在按细度增加的顺序排列的一系列筛子上，并将该块分成与筛孔相对应的部分。 4.2 这些测试方法用于确定粒度分布，因此可用于确定批间均匀性。 4.3 塑料材料的粒度影响处理特性，有时会影响一些聚合物的加工特性。

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 A dry mass of plastic material is placed on a series of sieves arranged in order of increasing fineness and the mass is divided into fractions corresponding to the sieve opening. 4.2 These test methods are used to determine particle size distribution and therefore are useful for determining lot-to-lot uniformity. 4.3 The particle sizes of plastic materials affect the handling characteristics and sometimes will affect the processing characteristics of some polymers.