氚气标准源活度浓度测量不确定度分析

氚气标准源的活度浓度量值对于氚活度浓度监测与校准的溯源非常重要，对于氚气活度浓度的测量，通常采用长度补偿法，本研究基于内充气正比计数器测量氚活度浓度的方法，对测量结果不确定度的来源进行了分析，并给出了评定结果。氚活度浓度的不确定度主要来源于本底与计数的统计涨落、体积测量、死时间修正、壁效应修正、以及测量重复性与稳定性。结果表明，对于7×10³ Bq/L的氚气标准源，其活度浓度测量结果的合成标准不确定度u_c=1.6%。

Uncertainty Analysis of Activity Concentration Measurement of Tritium Gas Standard Source

The value of activity concentration of tritium standard source is very important for the monitor and calibration of tritium. The length compensation method is applied for measuring activity of tritium. The analysis and uncertainty evaluation results of measuring uncertainty is given based on internal inflatable proportional counter The uncertainty of the activity concentration of tritium mainly came from the statistical fluctuation of background and count, volume measurement, dead time correction, wall effect correction, and measurement repeatability and stability. The results show that the standard uncertainty of synthesis is 1.6% for 7×10³ Bq/L tritium gas.