水中总碱度测定的不确定度评定

以水中总碱度为例，分析了测试过程中不确定度的来源，对各不确定度分量进行评定及合成，并计算得出合成不确定度和扩展不确定度。结果表明，对本测试方法影响较大的不确定度分量是标准物质配制、溶液体积引入和标定过程中的随机因素。在样品重复测定的条件下，测定结果的不确定度仅与溶液中的质量浓度有关。

The Uncertainty Evaluation In Determination of Total Alkalinity in Water

With the determination of total alkalinity in water as an example,this article analyses the source of uncertainty in the testing process,evaluates and combines each uncertainty and calculates the combined uncertainty and expanded uncertainty.The results show that this test method is greatly influenced by the following uncertainties: the preparation of reference materials,the volume of the introduced solution and the random factors in the calibration process.In the condition of repeated measurement of the sample,the uncertainty of the measurement result is related to the solution weight concentration only.