大容积密闭容器背压法漏率检测关键技术研究

围绕容积为10⁴cm³量级的密闭容器开展背压法漏率检测关键技术研究,分析了压氦压力、压氦时间、容器内外壁气体解吸附等因素对实验结果的影响机制,建立了一套可用于大容积密闭容器的背压法检漏流程。理论和实验研究结果表明,将背压法用于预制漏率为10^-6Pa·m³/s量级的大容积密闭容器的漏率检测是可行的。随着漏孔漏率的降低(低于10^-7Pa·m³/s量级),试验件的最低可检漏率也将逐渐低于氦质谱检漏仪的有效检测漏率,而由于被检对象的本底漏率值无法提前获知,将造成将背压法用于更低漏率的大容积密闭容器的漏率测试结果误差极大地增加。相关研究结果对于大容积密闭容器的漏率检测具有一定的理论指导价值。

Back-Pressurizing Leak Detection of Airtight Container with Large Volume

We addressed the back-pressurizing leak detection of airtight container with a large volume up to 1.17×10⁴ cm³. The influence of the leak detection conditions, including the adsorption/desorption of residue gases on inside/outside surfaces, and pressure and holding time of pre-injected helium, on the leakage-rate was theoretically analyzed and experimentally measured with the lab-built test platform. The results show that at a predicted leakagerate in the order of 10^-6Pa·m³/s, the back-pressurizing leak detection works pretty well. When it comes to the lowest detectable leakage-rate at a predicted leakage-rate below 10^-6 Pa·m³/s, especially below 10^-7 Pa·m³/s, the back-pressurizing leak detection outperformed the conventional one with helium mass spectrometer. The problem of large error remains to be solved to more accurately predict the background leakage-rate of the large-sized container with a leakage-rate below 10^-7 Pa·m³/s.