火花源发射光谱法测定生铁中硅的不确定度评定

Uncertainty Assessment of Spark Source Emission Spectrometry in Measurement of Silicon Content in Pig Iron

对ARL-4460型直读光谱仪测定生铁中硅元素含量的不确定度进行了评定,通过建立数学模型,对评定过程中不确定度的来源及其组成分量进行分析与计算。计算结果得出生铁中硅元素测量结果的合成不确定度为0.012%,扩展不确定度为0.024%。由评定结果可以看出,工作曲线的变动性分量是影响合成不确定度的最重要因素,工作曲线的变动性分量同时也受到未知样品浓度及测量次数的影响。在测量条件与评定条件一致的情况下,此次不确定度评定结果可直接应用于日常测定工作中。

The uncertainty measurement of silicon content in pig iron by ARL-4460 direct read spectrometer was assessed and uncertainty sources and their components in assessing were analyzed and calculated by establishing mathematical model. The calculation derived 0.012% combined uncertainty and 0.024% extended uncertainty from the measurement results of silicon in pig iron. Assessment results showed that the variability component of working curve, the most important factor influencing combined uncertainty, was affected by unknown sample concentration and measurement frequency as well. In case measurement conditions are consistent with that of assessment, the uncertainty result of this assessment can be directly applied to routine measurement.