1.1 这些测试方法使用透气性来确定粉末的包络比表面积及其相关的平均等效球形直径（0.2至75µm）。描述了两种试验方法:一种是无机材料的试验方法（试验方法1），另一种是有机材料的试验方法（试验方法2）。获得的值并非绝对值，但通常在相对基础上用于控制目的。 1.2 单位- 除用于确定密度的密度值和质量值外，使用克每立方厘米（g/cm 3. )和克（g）单位是长期的行业惯例；和压力单位，cm H 2. O–也是长期实践；以国际单位制为单位的数值应视为标准值。 1.3 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。 1.4 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 这些测试方法提供了确定粉末包络比表面积的程序，根据该程序计算“平均”粒径，假设颗粒为单粒径、光滑表面、无孔球形颗粒。因此，通过这些试验方法获得的值将作为平均粒径报告。这些测试方法的结果与所用粉末质量之间的相关性程度将随每个特定应用而变化，尚未完全确定。 4.2 这些试验方法通常适用于所有粉末，包括金属（见试验方法 B330型 对于特定的金属粉末要求）、陶瓷和有机材料，适用于直径在0.2到75µm之间的颗粒。它们不应用于由形状远离等轴的颗粒组成的粉末，即薄片或纤维。在这些情况下，只允许使用有关各方之间协议规定的试验方法。这些试验方法不得用于不同粉末的混合物，也不得用于含有粘合剂或润滑剂的粉末。当粉末含有附聚物时，测量的表面积可能会受到附聚程度的影响。消除团聚的方法，如实践中规定的方法 B859 如果有关各方同意，可以使用。 4.3 当通过这些方法确定粉末的“平均”粒径时，应清楚地记住，该平均粒径是通过使用仅适用于均匀尺寸和球形粉末的关系确定粉末的比表面积得出的。 因此，这些方法的结果仅为 估计 平均粒径。 4.4 所报告的粒度测量是实际尺寸和形状因子以及被测颗粒的特定物理或化学性质的函数。当比较在不同物理或化学参数或不同粒度测量范围下运行的仪器的数据时，需要谨慎。样品采集、处理和制备也会影响报告的粒度结果。

1.1 These test methods use air permeability to determine an envelope-specific surface area and its associated average equivalent spherical diameter (from 0.2 to 75 µm) of powders. Two test methods are described: One test method for inorganic materials (Test Method 1), and another test method for organic materials (Test Method 2). The values obtained are not intended to be absolute but are generally useful on a relative basis for control purposes. 1.2 Units— With the exception of the values for density and the mass used to determine density, for which the use of the gram per cubic centimetre (g/cm 3 ) and gram (g) units is the longstanding industry practice; and the units for pressure, cm H 2 O – also long-standing practice; the values in SI units are to be regarded as standard. 1.3 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. 1.4 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 provide procedures for determining the envelope-specific surface area of powders, from which is calculated an “average” particle diameter, assuming the particles are monosize, smooth surface, nonporous, spherical particles. For this reason, values obtained by these test methods will be reported as an average particle size. The degree of correlation between the results of these test methods and the quality of powders in use will vary with each particular application and has not been fully determined. 4.2 These test methods are generally applicable to all powders, including metals (see Test Methods B330 for specific metal powder requirements), ceramics, and organic materials, for particles having diameters between 0.2 and 75 µm. They should not be used for powders composed of particles whose shape is too far from equiaxed – that is, flakes or fibers. In these cases, it is permissible to use the test methods described only by agreement between the parties concerned. These test methods shall not be used for mixtures of different powders, nor for powders containing binders or lubricants. When the powder contains agglomerates, the measured surface area may be affected by the degree of agglomeration. Methods of de-agglomeration such as that specified in Practice B859 may be used if agreed upon between the parties concerned. 4.3 When an “average” particle size of powders is determined by these methods, it should be clearly kept in mind that this average size is derived from the determination of the specific surface area of the powder using a relationship that is true only for powders of uniform size and spherical shape. Thus, the results of these methods are only estimates of average particle size. 4.4 Reported particle size measurement is a function of both the actual dimension and shape factor as well as the particular physical or chemical properties of the particle being measured. Caution is required when comparing data from instruments operating on different physical or chemical parameters or with different particle size measurement ranges. Sample acquisition, handling, and preparation can also affect reported particle size results.