比较法校准氦真空参考漏孔漏率及合成不确定度评定

直接比对法是氦质谱检漏仪在稳定工作和引入气体相同条件下,将参考漏孔流出的氦气和标准漏孔提供的已知流量的氦气分别引入校准室中,用氦质谱检漏仪分别测量氦气产生的离子流,通过比较两次离子流的测量值计算出参考漏孔漏率的一种校准方法。这种校准范围为1×10-7Pa.m3/s~1×10-10Pa.m3/s。对同一参考漏孔,采用同样的校准测量,可以采用高斯分布统计的方法获得校准不确定度,其他不确定度分量由氦质谱检漏仪组成的校准装置决定,其合成相对不确定度可达到10%。

A comparison method for calibrating leakage rate of helium vacuum reference leak and synthesis uncertainty assessment

Comparison method is to introduce the helium gas that flow from reference leak and the known quantity helium that from standard leak into a calibrating chamber,then measuring the ion flux using helium mass spectrometry leak detector when it works steadily.By comparing the test values of two ion flux,the leakage rate of reference leak can be calculated.The calibrating range for reference leak is from 1 ×10-10 Pa·m3/s to 1×10-7 Pa·m3/s.As for the same reference leak,when using the same calibrating method,we can adopt Gauss distributing statistics to get the calibrating uncertainty,and other uncertainty components are determined by the adjusting devices,the whole uncertainty of those can achieve to 10%.