基于Elementar vario MACRO cube型元素分析仪测定固体生物质燃料中碳、氢、氮含量的方法原理,建立了测量数学模型,研究分析了测定结果的不确定度来源,评定了测量重复性、校准曲线、样品称量以及校准物质纯度引入的不确定度分量,并通过对合成标准不确定度及扩展不确定度的计算,得出了元素分析仪测定固体生物质燃料中碳、氢、氮含量的不确定度.结果表明,影响固体生物质燃料中碳、氢、氮含量测量不确定度的主要来源是测量重复性与校准曲线,样品质量与校准物质纯度引入的不确定度较小,最终得到的固体生物质燃料样品中碳、氢、氮含量与不确定度为:碳元素(43.63±0.18)%,氢元素(5.23±0.05)%,氮元素(0.83±0.05)%,其中k=2.
Evaluation of uncertainty in determination of carbon,hydrogen and nitrogen content in solid biofuels by using elemental analyzer
The measurement model of determination of carbon,hydrogen and nitrogen content in solid biofuels by using elementar vario MACRO cube analyzer was eastablished.The sources of uncertainty were analyzed.The uncertanty componetnts such as repetiton of measurement,calibration curve,sample mass as well as reagent purity of curve calibration were evaluated.Moreover,the uncertainty in determination of carbon,hydrogen and nitrogen content in solid biofuels by using elemental analyzer was obatined through the calculation of the combined standard uncertainty and expanded uncertainty.The results showed that the main sources which affected the measurement uncertainty of carbon,hydrogen and nitrogen content in solid biofuel were repetiton of measurement and calibration curve.Sample mass and the reagent purity of curve calibration introduced less uncertainty.The final content and uncertainty of carbon,hydrogen and nitrogen in solid biofuels were:carbon(43.63±0.18)%,hydrogen(5.23±0.05)%,nitrogen(0.83±0.05)%,among which k=2.
solid biofuelelemental analyzercarbon,hydrogen and nitrogen contentuncertaintyevaluation
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万方数据
