1.1 这些试验方法包括测定最大孔径为0.1至15.0μm的膜过滤器的两种孔径特性。 1.2 试验方法A提出了一种测量非纤维膜最大极限孔径的试验方法。极限直径是与给定孔隙最小截面面积相同的圆的直径( 图1 ). 图1 极限直径示例 1.3 试验方法B测量膜中规定孔径的相对丰度，定义为极限直径。 1.4 分析员应意识到，根据实践需要，有足够的协作数据用于偏差陈述 D2777 未提供。有关详细信息，请参阅精度和偏差部分。 1.5 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.6 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。 1.7 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====== 5.1 本试验方法可用于: 5.1.1 确定过滤器的最大孔径， 5.1.2 比较几种过滤器的最大孔径，以及 5.1.3 确定过滤、涂层或高压灭菌等各种过程对膜最大孔径的影响。 5.2 膜过滤器从膜的一侧到另一侧具有离散孔，类似于毛细管。泡点测试的原理是，润湿液体通过毛细管吸引力和表面张力保持在这些毛细管孔中，迫使液体离开这些孔所需的最小压力是孔径的函数。本试验中出现稳定气泡流的压力为泡点压力。泡点测试不仅对指示最大孔径有重要意义，还可能指示膜损坏、密封失效或系统泄漏。 5.3 本试验方法的结果不应作为描述流体中颗粒污染物截留极限尺寸的唯一因素。 根据本试验方法计算的有效孔径基于毛细管孔具有圆形横截面的前提，而不是实际的粒径保留。见测试方法 E128 了解更多信息。

1.1 These test methods cover the determination of two of the pore size properties of membrane filters with maximum pore sizes from 0.1 to 15.0 μm. 1.2 Test Method A presents a test method for measuring the maximum limiting pore diameter of nonfibrous membranes. The limiting diameter is the diameter of a circle having the same area as the smallest section of a given pore ( Fig. 1 ). FIG. 1 Examples of Limiting Diameters 1.3 Test Method B measures the relative abundance of a specified pore size in a membrane, defined in terms of the limiting diameter. 1.4 The analyst should be aware that adequate collaborative data for bias statements as required by Practice D2777 is not provided. See the precision and bias section for details. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 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. 1.7 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 ====== 5.1 This test method may be used to: 5.1.1 Determine the maximum pore size of a filter, 5.1.2 Compare the maximum pore sizes of several filters, and 5.1.3 Determine the effect of various processes such as filtration, coating, or autoclaving on the maximum pore size of a membrane. 5.2 Membrane filters have discrete pores from one side to the other of the membrane, similar to capillary, tubes. The bubble point test is based on the principle that a wetting liquid is held in these capillary pores by capillary attraction and surface tension, and the minimum pressure required to force liquid from these pores is a function of pore diameter. The pressure at which a steady stream of bubbles appears in this test is the bubble point pressure. The bubble point test is significant not only for indicating maximum pore size, but may also indicate a damaged membrane, ineffective seals, or a system leak. 5.3 The results of this test method should not be used as the sole factor to describe the limiting size for retention of particulate contaminants from fluids. The effective pore size calculated from this test method is based on the premise of capillary pores having circular cross sections, and does not refer to actual particle size retention. See Test Method E128 for additional information.