非统计方法估计的不确定度分量的自由度

Degrees of Freedom of the Uncertainty Components Estimated with the Non-statistical Method

本文讨论了不确定度评定中非统计法估计的不确定度分量自由度的分析和计算 ,给出了由扩展不确定度计算自由度的表达式。指出这类不确定度分量的自由度计算中应区分使用标准不确定度和扩展不确定度。目前国内外有关不确定度评定的法规性文献中均未作这一区分。由此会造成自由度计算的混乱 ,方法不当所给结果会出现大的差错 ,因而对按 t分布确定的合成总扩展不确定度产生显著影响 。

This paper discusses the calculation and analysis of degrees of freedom,when evaluating uncertainty,presents the expression of degrees of freedom according to extended uncertainty,as for the uncertainty components estimated with non statistical method,and points out that the standard uncertainty and the extended uncertainty should be distinguished,when calculating degrees of freedom of the uncertainty components.Now,it has not been distinguished yet in international regulations about evaluating uncertainty,which cause great confusion when calculating degrees of freedom,and because of using improper methods,there will be larger errors in the results.Thus,it influences noticeably the composition of the extended uncertainty which is determined according to t distribution,and so,enough attention should be given.