煤中铬含量测量结果的不确定度评定

Uncertainty Evaluation of Measuring Results of Chromium Content in Coal

摘要

基于火焰原子吸收分光光度计法测定煤中铬含量的方法建立测量模型，从测量重复性、试样称量、标准曲线、标准溶液、定容体积，五个方面分析火焰原子吸收法测定煤中铬含量时其测量结果的不确定度来源；所测试样按照文中方法评定的煤中铬含量测量结果为Cr_ad=（62±6）μg/g；k=2。（k为95%概率下的包含因子）；在煤中铬含量的测量不确定度各分量中，测量重复性和标准曲线这两个分量的影响最大，在日常检测中，应严格控制重复性测定条件和配置标准曲线时选用精度良好的量具，同时，尽可能完善实验室的操作环境和不断提高实验操作人员的业务综合素质，以提高测量结果的精密度及准确度。

Abstract

This study establishes a measurement model for determining chromium content in coal using flame atomic absorption spectrophotometry (FAS). The uncertainty sources in FAS measurements are analyzed from five aspects: measurement repeatability, sample weighing, standard curve, standard solution, and volumetric volume. The evaluated chromium content in coal samples, determined by the method described in this paper, is Cr_ad= (62±6) μg/g with a k value of 2 (where k represents the 95% confidence interval). Among the components of measurement uncertainty, repeatability and standard curve have the most significant impacts. In daily testing, strict control of repeatability conditions and the use of precision instruments for standard curve preparation are essential. Additionally, improving laboratory operational environments and continuously enhancing the professional competence of laboratory personnel are crucial to enhance measurement precision and accuracy.

关键词

煤 / 铬含量 / 测量结果 / 测量不确定度 / 不确定度分量 / 评定

Key words

coal / chromium content / measurement result / measurement uncertainty / uncertainty component / evaluation

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