基于分光光度法的甲醛动态配气装置量值溯源研究

Metrological traceability research of calibration unit for formaldehyde gas by dynamic method based on spectrophotometry

针对甲醛动态配气装置量值溯源难点,提出了基于分光光度法原理的新溯源方法。提供了详细的测量步骤和模型,并对各不确定度分量进行了充分地分析和评估,给出了分别采用线性回归和单点匹配两种方法在甲醛气体质量浓度为1~2 mg/m^(3)与0~2 mg/m^(3)时的不确定度评定实例,不确定度评定结果分别为U_(rel)=3.1%~3.7%、k=2与U_(rel)=2.7%、k=2。通过采样和液体吸收方式实现了甲醛气体质量浓度溯源至甲醛水溶液标准物质,既是对现有甲醛计量标准溯源方法的补充,也可用于甲醛气体质量浓度的量值比对和验证。

Focusing on the difficulty in metrological traceability of calibration unit for formaldehyde gas by dynamic method,a new strategy based on spectrophotometry principle was proposed.All the detailed steps and models were provided.Every known contribution of uncertainty was well analyzed and estimated.Two examples of uncertainty evaluation with range of 1~2 mg/m^(3) and 0~2 mg/m^(3) formaldehyde mass concentration,based on linear regression calibration and exact-match calibration separately,were presented.The expand relative uncertainty of the two methods are estimated as U_(rel)=3.1%~3.7%,k=2 and U_(rel)=2.7%,k=2,respectively.By means of sampling and liquid absorption,the mass concentration of formaldehyde gas can be traced to that of the reference material of formaldehyde aqueous solution directly,which is not only a supplement for the commonly traceability methods,but also used for the mass concentration comparison and verification of formaldehyde gas.