EDTA滴定法测定水中总硬度的不确定度评定

依据测量不确定度盼浮定原理和方法，通过EDTA滴定法测定水中总硬度的实例，分析不确定度来源，确定不确定度数学模型。讨论了影响总硬度测定值不确定的各种因素，计算了相对标准不确定度分量、合成标准不确定度和扩展不确定度。结果表明，影响其测量不确定度的主要因素是测量熏复性。在总硬度为214．1mg·L-1的水样测定中，相对标准不确定度为0．42％。

Evaluation of Uncertainty for Determination of Total Hardness in Water by EDTA Titration

Based on the method and principle of uncertainty evaluation, through the example of determination total hardness in water by the EDTA titration, the sources of uncertainty were analyzed and the mathematical model of the uncertainty was established. Some factors influencing the uncertainty of the test results of total hardness in water were discussed. The components of related standard uncertainty, combined standard uncertainty, and expanded uncertainty were calculated. The results showed that determination ...