摘要
用氮气中水气体标准物质和内置水分发生器分别校准仪器,测量氮气中痕量水,并对测定结果的不确定度进行评定。不确定度来源主要包括单点线性校准、测量随机效应、影响准确测量的仪器参数和氮气中水气体标准物质4个方面,合成得到相对示值误差的扩展不确定度。当测试点的摩尔分数分别为4.3、51.8、99.7μmol/mol时,采用标准气体校准时相对示值误差的扩展不确定度分别为5.5%、4.4%、5.2%,采用水分发生器校准时相对示值误差的扩展不确定度分别为6.1%、4.8%、6.3%。在测量区间1~100μmol/mol范围内,离校准点越远,单点线性校准引入的不确定度越大,校准曲线的精确度和可信度越差;测试点量值越大,外部物理条件引入的不确定度就越大;不同校准途径对相对示值误差不确定度的影响不大。
After calibrating the instrument with water gas standard substance in nitrogen and built-in moisture generator,respectively,and then trace water in nitrogen was measured to evaluate the uncertainty of the measurement results.The sources of uncertainty mainly included single point linear calibration,measurement random effects,the parameters affecting the accurate measurement,and water gas standard substance in nitrogen.The extended uncertainty of relative indication error was synthesized.When the mole fractions of the test points were 4.3,51.8,99.7μmol/mol,the extended uncertainty of the indication error were 5.5%,4.4%,5.2%with calibrating the instrument by gas standard substance,and 6.1%,4.8%,6.3%with calibrating the instrument by built-in moisture generator,respectively.Within the measurement range of 1-100μmol/mol,the further away from the calibration point,the greater the uncertainty introduced by single point linear calibration,and the lower the accuracy and reliability of the calibration curve;The larger the measurement value of the test point,the greater the uncertainty introduced by external physical conditions;The impact of different calibration methods on the uncertainty of relative indication error is not significant.
作者
蔡光华
CAI Guanghua(Changshu Metrological Measuring Institute,Changshu 215000,China)
出处
《化学分析计量》
CAS
2024年第9期111-116,共6页
Chemical Analysis And Meterage
关键词
石英晶体振荡法
气体中痕量水
不确定度
quartz crystal oscillation method
trace water in gas
uncertainty
