Uncertainty analysis in determination of mercury in coal by direct mercury analyzer
Mercury content is one important index in quality evaluation of commercial coal.To reasonably character-ize the measured value of mercury content,we need to analyze and evaluate the dispersivity caused by system impact and randam impact in determination of mercury,which is the measurement uncertainty.In this paper,the main re-sources of the uncertainty evaluation in determination of mercury in coal by direct mercury analyzer was analyzed.By statistically calculating the relative uncertainty,composite uncertainty,and expanded uncertainty of each component,the uncertainty of mercury content determination in coal was obtained.The results show that the uncertainty that lead by pipettes,volumetric flasks and micropipette used in the process of drawing work curve is the highest,and which is 1.38×10-2.The uncertainty introduced by sample weighing,mercury standard solution,curve fitting,measurement repeatability,etc.is relatively small.By selecting appropriate nonlinear curve fitting uncertainty evaluation methods,it is comprehensively concluded that the uncertainty of using the direct mercury meter method to determine the mercu-ry in coal for the test sample is(0.104±0.006)μg/g,k=2.
mercury content in coaldirect mercury analyzermeasurement uncertaintyanalysis of uncertainty sourcesencertainty evaluation of nonlinear curve fittingworking curvemeasurement repeatabilitystandard solution
万方数据
维普
