1.1 本试验方法包括使用自动仪器测定厚度为40 mm的透明石油产品、生物柴油和生物柴油混合物的浊点。 1.2 仪器的测量范围为-65 °C至+51 °C，但精度声明仅来自浊点温度为-50℃的样品 °C至+6 °C。 1.3 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。 1.4 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。 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====== 5.1 石油产品和生物柴油的浊点是其在某些应用中的最低使用温度的指标。足够数量的蜡晶体可以堵塞某些燃油系统中使用的滤清器。 5.2 石油混合操作需要精确测量浊点。 5.3 该试验方法可以确定蜡晶体形成的试样温度，在该温度下，蜡晶体可以以0.1的分辨率观察为云 °C。 5.4 该测试方法提供的结果表明，当校正偏差并四舍五入到下一个较低的整数时（参见 12.2 )，已发现与试验方法等效 D2500 . 5.5 该试验方法在比试验方法要求的更短时间内确定浊点 D2500 .

1.1 This test method covers the determination of the cloud point of petroleum products, biodiesel, and biodiesel blends that are transparent in layers 40 mm in thickness, using an automatic instrument. 1.2 The measuring range of the apparatus is from –65 °C to +51 °C, however the precision statements were derived only from samples with cloud point temperatures from –50 °C to +6 °C. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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. 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 ====== 5.1 The cloud point of petroleum products and biodiesel fuels is an index of the lowest temperature of their utility for certain applications. Wax crystals of sufficient quantity can plug filters used in some fuel systems. 5.2 Petroleum blending operations require precise measurement of the cloud point. 5.3 This test method can determine the temperature of the test specimen at which wax crystals have formed sufficiently to be observed as a cloud with a resolution of 0.1 °C. 5.4 This test method provides results that, when corrected for bias and rounded to the next lower integer (see 12.2 ), have been found equivalent to Test Method D2500 . 5.5 This test method determines the cloud point in a shorter time period than required by Test Method D2500 .