对EDTA容量法检测氧化镧中稀土总量的不确定度进行了评定,分析不确定度的主要来源,评估检测过程中不确定度分量,计算了检测结果的合成标准不确定度和扩展不确定度。当氧化镧中稀土总量为98.61%时,扩展不确定度为0.38%(k=2)。 The uncertainty of the total amount of rare earths in Lanthanum Oxide by EDTA volumetric method was evaluated, the main sources of uncertainty were analyzed, the components of uncertainty in the testing process were evaluated, and the composite standard uncertainty and extended uncertainty of the test results were calculated degree. When the total amount of rare earth in lanthanum oxide is 98.61%, the extended uncertainty is 0.38% (k = 2).