1.1 本试验方法包括测定水的淤泥密度指数（SDI）。该测试方法可用于指示水中颗粒物的数量，适用于浊度相对较低（<1.0 NTU）的水，如井水、过滤水或澄清的出水样品。由于水中颗粒物的大小、形状和性质可能会有所不同，因此本试验方法不是颗粒物数量的绝对测量方法。 1.2 本试验方法不适用于规范的试剂级水I、II和III类 D1193 ，或来自大多数反渗透和超滤系统的流出物。 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）。本标准的使用者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====== 5.1 SDI可以作为水中颗粒物数量的有用指示。 5.2 SDI可用于确定各种工艺的有效性，如用于去除颗粒物的过滤或澄清。 5.3 SDI已与一些水处理设备（如反渗透装置）的结垢趋势进行了经验关联。 5.4 SDI可以作为水温的函数而变化，并且在不同温度下获得的值可能不一定是可比较的。 5.5 SDI可能因薄膜过滤器制造商而异。因此，使用来自不同膜制造商的过滤器获得的SDI值可能不具有可比性。

1.1 This test method covers the determination of the silt density index (SDI) of water. This test method can be used to indicate the quantity of particulate matter in water and is applicable to relatively low (<1.0 NTU) turbidity waters such as well water, filtered water, or clarified effluent samples. Since the size, shape, and nature of particulate matter in water may vary, this test method is not an absolute measurement of the quantity of particulate matter. 1.2 This test method is not applicable for reagent grade water Types I, II, and III of Specification D1193 , or effluents from most reverse osmosis and ultrafiltration systems. 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 The SDI can serve as a useful indication of the quantity of particulate matter in water. 5.2 The SDI can be used to determine effectiveness of various processes such as filtration or clarification used to remove particulate matter. 5.3 The SDI has been empirically correlated with the fouling tendency of some water treatment equipment such as reverse osmosis devices. 5.4 The SDI may vary as a function of water temperature, and values obtained at different temperatures may not necessarily be comparable. 5.5 The SDI can vary with the membrane filter manufacturer. Thus, SDI values obtained with filters from different membrane manufacturers might not be comparable.