煤中氟测量结果不确定度评定

Evaluation of uncertainty of measurement results for fluorine determination in coal

煤中氟采用高温燃烧水解一氟离子选择电极法测定,以实测数据为例详细阐述了煤中氟测量的不确定度评定方法。基于测定方法建立测量模型,从测量重复性、样品质量、燃烧水解、氟标准溶液、氟电极斜率曲线、电位测量来分析不确定度来源,计算每个来源的标准不确定度分量以及合成标准不确定度。其中,由氟电极斜率曲线测定引起的相对标准不确定度的贡献最大。详细阐述了利用残余标准偏差估算氟电极斜率曲线的相对不确定度过程,为评定其它煤炭分析项目提供借鉴。

The fluorine in coal can be determined by high temperature combustion hydrolysis-fluorine ion selective electrode method.In this paper,the uncertainty evaluation method of fluorine in coal was described in detail with the measured data as an example.Based on the method,the measurement model was established,from aspects such as repeatability of measurements,sample quality,combustion hydrolysis,fluorine standard solution,fluorine electrode slope curve and potential measurement,the sources of uncertainty were analyzed.The standard uncertainty components of each source were calculated,as well as the synthetic standard uncertainty.Among them,relative standard uncertainty caused by fluorine electrode slope curve made the biggest contribution.This paper described in detail the process of estimating the relative uncertainty of the slope curve of fluorine electrode by residual standard deviation,and provided the reference for the evaluation of other coal analysis projects.