1.1 本试验方法涵盖金属粉末粒度分布的测定。经验表明，本试验方法适用于分析元素钨、碳化钨、钼和钽粉末，根据试验方法测定，所有粉末的估计平均粒径均为6μm或更小 B330型 . 其他金属粉末（例如，元素金属、碳化物和氮化物）可使用本试验方法进行分析，并注意重要性，直到获得实际满意的经验（见 7.2 ). 该程序包括在以下两种条件下测定粉末的粒度分布: 1.1.1 粉末供应时（供应时），以及 1.1.2 按照实践中的描述，粉末通过棒磨脱胶后 B859 . 1.2 本试验方法适用于密度均匀、成分均匀、粒径分布范围为0.1至100μm的颗粒。 1.2.1 然而，本试验方法中使用的尺寸和沉降速度之间的关系假设颗粒在层流状态下沉降。这要求颗粒的雷诺数小于等于0.3。由于湍流，雷诺数较大的颗粒沉降的粒度分布分析可能不正确。如果存在大于25μm的颗粒，本试验方法涵盖的一些材料可能会在雷诺数大于0.3的情况下沉降。该试验方法的使用者应计算预期出现的最大颗粒的雷诺数，以判断所得结果的质量。雷诺数（Re）可以使用流动方程计算 哪里 D = 预计出现的最大颗粒的直径， ρ = 颗粒密度， ρ 0 = 悬浮液密度， g = 重力引起的加速度，以及 η = 是悬浮液的粘度。 雷诺数为0时可分析的最大颗粒表。 对于水中的许多金属，在35°C的条件下，给出了3或更少 表1 . 对于每种材料，还给出了在同一液体系统中沉积的30μm颗粒的雷诺数计算列。 1.3 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. )而克（g）单位是长期的行业惯例，以国际单位制为单位的数值应视为标准。 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。第节给出了具体的危险信息 7. . 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 本试验方法对粉末生产商和采购商都很有用，如中所述 1.1 和 1.2 ，用于确定产品规格、制造控制、开发和研究的粒度分布。 4.2 用户应注意，本试验方法中使用的样品浓度可能不是某些权威机构认为理想的浓度，并且本试验方法的范围延伸到布朗运动可能是常规沉降中一个因素的区域。在本试验方法的范围内，样品浓度和布朗运动均不显著。 4.3 所报告的粒度测量是实际颗粒尺寸和形状因子以及所测量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 This test method covers the determination of particle size distributions of metal powders. Experience has shown that this test method is satisfactory for the analysis of elemental tungsten, tungsten carbide, molybdenum, and tantalum powders, all with an as-supplied estimated average particle size of 6 μm or less, as determined by Test Method B330 . Other metal powders (for example, elemental metals, carbides, and nitrides) may be analyzed using this test method with caution as to significance until actual satisfactory experience is developed (see 7.2 ). The procedure covers the determination of particle size distribution of the powder in the following two conditions: 1.1.1 As the powder is supplied (as-supplied), and 1.1.2 After the powder has been deagglomerated by rod milling as described in Practice B859 . 1.2 This test method is applicable to particles of uniform density and composition having a particle size distribution range of 0.1 up to 100 μm. 1.2.1 However, the relationship between size and sedimentation velocity used in this test method assumes that particles sediment within the laminar flow regime. This requires that the particles sediment with a Reynolds number of 0.3 or less. Particle size distribution analysis for particles settling with a larger Reynolds number may be incorrect due to turbulent flow. Some materials covered by this test method may settle with Reynolds number greater than 0.3 if particles greater than 25 μm are present. The user of this test method should calculate the Reynolds number of the largest particle expected to be present in order to judge the quality of obtained results. Reynolds number (Re) can be calculated using the flowing equation where D = the diameter of the largest particle expected to be present, ρ = the particle density, ρ 0 = the suspending liquid density, g = the acceleration due to gravity, and η = is the suspending liquid viscosity. A table of the largest particles that can be analyzed with Reynolds number of 0.3 or less in water at 35°C is given for a number of metals in Table 1 . A column of the Reynolds number calculated for a 30–μm particle sedimenting in the same liquid system is given for each material also. 1.3 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, the values in SI units are to be regarded as standard. 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. Specific hazard information is given in Section 7 . 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 This test method is useful to both producers and purchasers of powders, as outlined in 1.1 and 1.2 , in determining particle size distribution for product specifications, manufacturing control, development, and research. 4.2 Users should be aware that sample concentrations used in this test method may not be what is considered ideal by some authorities, and that the range of this test method extends into the region where Brownian movement could be a factor in conventional sedimentation. Within the range of this test method, neither the sample concentration nor Brownian movement are believed to be significant. 4.3 Reported particle size measurement is a function of both the actual particle dimension and shape factor as well as the particular physical or chemical properties 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.