重量法测定工业磷酸中磷酸含量的测量不确定度评定

Evaluation of the Measurement Uncertainty for the Determination of Phosphoric acid contents in Phosphoric acid for industry use by Gravimetric Analysis

按照测量不确定度评定的通用规则,建立了数学模型,对重量法测定工业磷酸中磷酸含量的测量不确定度进行了评定,分析了方法中的不确定度分量及其来源,计算了各分量的不确定度,最后计算出了检测结果的合成标准不确定度和扩展不确定度。检测结果和不确定度评定结果为(85.200.26)%,k=2。洗涤沉淀造成沉淀损失引起的测量不确定度分量为最大。

According to JJF1059 -1999＂ Evaluation and Expression of Uncertainty in Measurement＂, A mathematic model for the determination of phosphoric acid contents in phosphoric acid for industry use by gravimetric analysis was established. The calculation formula was deduced. Some data were collected in the procedure of analyzing the sample and the uncertainties of various variables were calculated. The combined uncertainty and expanded uncertainty were finally obtained by synthesizing the and evaluation of the measurement uncertainty uncertainties of various component variables. Results of determination were （ 85. 200.26） % , k = 2. The major source of uncertainty was the loss of precipitate by washing.