燃料用二甲醚 (DME). 水含量的测定. 卡尔·费休滴定法

[中文适用范围]： 本标准规定了采用卡尔费休滴定法测定燃料用二甲醚中水含量的试验程序。 该程序适用于测定 ISO 16861 规定值以内的水含量。 该测试方法适用于市售库仑（或容量）卡尔费休试剂，以及测定 DME 添加剂、润滑油、基础油、自动变速箱油、碳氢溶剂和其他石油产品。 通过正确选择样本量，该测试方法可用于测定从 mg/kg (ppm) 到百分比浓度的水。 注：该方法的精度已由有限数量的实验室针对有限的样品和含量水平进行了研究。 它允许建立 DME 的质量规范，但不能被视为符合 ISO 4259 中常用统计方法的完全精确测定。 [外文原描述]： ISO 17197:2014 specifies a procedure of test for the amount of water content in DME used as fuel by the Karl Fischer titration method. This procedure is applicable to determine the amount of water up to the value specified in ISO 16861. This test method is intended for use with commercially available coulometric (or volumetric) Karl Fischer reagents and for the determination of water in DME additives, lube oils, base oils, automatic transmission fluids, hydrocarbon solvents, and other petroleum products. By proper choice of the sample size, this test method can be used to determine water from mg/kg (ppm) to percent level concentrations. NOTE The precision of this method has been studied for a limited set of samples and content levels by a limited amount of labs. It allows establishment of a quality specification of DME but cannot be considered as a full precision determination in line with the usual statistical methodology as in ISO 4259.