一种下限为10^(-10)Pa·m^3/s的正压漏孔校准装置  

Novel Calibration Apparatus with Low Pressure Leak Detection Limit of 10^(-10)Pa·m^3/s

作　　者：卢耀文 刘志宏[1,2] 闫荣鑫 齐京[2,4] 王欢 田虎林 闫睿[1,2] 杨传森 查良镇[2,4] Lu Yaowen;LiD Zhihong;Yan Rongxin;Qi Jing;Wang huan;Tian Hulin;Yan Rui;Yang Chuansen;Cha Liangzhen(Beijing Engineering Technology Research Centerof Vacuum Measurement and Test ,Beijing100029,China;Beijing Orient Institute of Measurement and Test,Beijing 100029,China;Beijing Institute of Spacecraft Environment Engineering,Beijing 100094,China;Tsinghua University,Beijing 100084,China)

机构地区：[1]北京市真空计量检测工程技术研究中心,北京100029 [2]北京东方计量测试研究所,北京100029 [3]北京卫星环境研究所,北京100094 [4]清华大学,北京100084

出　　处：《真空科学与技术学报》2018年第12期1019-1024,共6页Chinese Journal of Vacuum Science and Technology

基　　金：项目编号:JSJL2015203B019

摘　　要：为了解决漏率小于10^(-8)Pa·m^3/s正压漏孔(示漏气体为He气)的校准问题,研制出下限可达10^(-10)Pa·m^3/s的校准装置。提出基于累积比较的正压漏孔校准方法,通过向漏孔入口充入100 kPa高纯度N_2气模拟大气压环境,将漏孔泄漏后的示漏气体引入累积室经过一段时间的累积来提高浓度,采用膨胀衰减压力和分子流进样将混合气体引入质谱分析室,提出对质谱分析室中示漏气体进行累积模式的测量方法,通过四极质谱计作为比较器分别测量漏孔泄漏形成的混合气及配置的标准混合气体在累积模式下离子流的变化率得到漏孔漏率,解决了无法测量微小示漏气体离子流信号的技术瓶颈;采用全金属密封结构和特殊的工艺处理解决了累积室中延伸下限由于本底示漏气体的影响因素,采用体积小于1 mL的取样室通过直接取样和膨胀衰减压力取样获得与漏孔累积后形成同等数量的标准混合气体,解决了微小漏率正压漏孔校准所用标准混合气体获得。为此基于累积比较法的正压漏孔校准方法实现了10^(-8)～10^(-10)Pa·m^3/s的校准范围,合成标准不确定度不超过7. 5%。A novel calibration apparatus,with a low pressure-leak detection limit of 10^-10Pa·m^3/s,was developed in cumulative comparison method.The original work included the built-in molecular flow gas-sampler,1ml in volume,all-metal ultra-high vacuum (UHV)system and minimization of background interference.First,the ultrapure argon atmospheric pressure at the pressure-leak's downstream was increased to 100kPa;next,after properly cumulating in a given gas-path,the leaked He trace-gas was released into the expansion chamber and filled through the gas-sampler into the quadrupole mass-spectrometer(QMS)analysis chamber,equipped with non-evaporable getter pump,and the time evolution of the He-ion currents of the test and well-defined reference gas-mixtures was measured with QMS and compared;finally,the leakage-rate of a pressure leak was calibrated.The results show that the newly-developed apparatus is capable of calibrating pressure leak in 10^-8~10^-10Pa·m^3/s range with a combined standard uncertainty below 7.5%.

关 键 词：正压漏孔 累积比较法 分子流动态进样 微小漏率漏孔 

分 类 号：TB77[一般工业技术—真空技术]