1.1 本试验方法包括使用45µm（325号）筛子通过空气喷射筛分通过空气喷射筛分测定水硬性水泥的细度。 1.2 以国际单位制表示的数值视为标准。国际单位制后括号中给出的值仅供参考，不被视为标准值。 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====== 5.1 本试验方法提供了评估符合性的数据，其中规范限制了在45µm（325号）筛上筛分时保留的材料量。

1.1 This test method covers the determination of the fineness of hydraulic cement by means of air jet sieving using a 45-µm (No. 325) sieve by Air Jet sieving. 1.2 The values stated in SI units are regarded as the standard. The values given in parentheses after SI units are provided for information only and are not considered 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 ====== 5.1 This test method provides data for assessing compliance where specifications limit the amount of material retained when sieved on a 45-µm (No. 325) sieve.