电位滴定法测定水中氯化物的不确定度评定研究

根据《测量不确定度评定与表示》（JJF 1059.1-2012）,建立了实验室电位滴定仪测定水中氯化物不确定度数学模型,分析了整个过程各种不确定度的影响因素,量化各不确定度分量,计算合成不确定度和扩展不确定度.本次测量结果为（110±6.18） mg/L,合成相对不确定度值为0.028 1,扩展不确定度为6.18 mg/L.电位滴定仪测定氯化物的不确定度主要来源是样品重复测定和滴定终点体积读数.

Uncertainty in Determining Chloride in Water by Potentiometric Titration Method

According to JJF1059.1 -2012, a mathematical model was built to evaluate the uncertainty for determination of chloride in water by potentiometric titration method. It analyzed the influence of various uncertainty factors on the whole process to quantify the uncertainty components, calculating synthetic uncertainty and expanding uncertainty. The measurement results were （110 ±6. 18）mg/L, synthetic relative uncertainty value was 0. 028 1, expanded uncertainty was 6. 18 mg/L. The major source of the uncertainty in the method was the sample repeated measurement and volume of end point of titration.