基于最小二乘法的氦质谱非真空累积检漏方法研究

摘要

航天器的密封性能测试分为部组件级测试和系统级测试.系统级密封性能测试大多采取氦质谱非真空累积检漏法,由于收集室内氦气浓度分布不均匀,检漏仪读数不稳定,漏率初值或终值的读取可能不准确,进而造成测量误差.提出一种基于最小二乘法拟合的氦质谱非真空累积检漏方法,在非真空累积过程中,多次读取收集室内漏率值,并利用最小二乘法对漏率变化率进行拟合,进而求出被检件漏率.大量试验结果表明,与传统的氦质谱非真空累积检漏法相比,该方法可有效避免单次数据测量造成的测量误差,具有更高的数据可信度.%Spacecraft leak testing is divided into component testing and system testing. System leak test mostly take the method of non-vacuum accumulation leak testing by helium mass spectroscopy. Due to the uneven distribution of heli-um in the accumulation chamber and the unstable readings of helium mass spectrometer leak detector,the initial and final leakage rate values may not be read accurately which may result in the measurement error. In this paper,a non-vacuum ac-cumulation leak testing by helium mass spectroscopy based on least square method is introduced. In the process of helium gas accumulation,read the helium gas density in the accumulation chamber at regular intervals and calculate the helium gas density charge rate using least square method. Then,the leakage rate of the object under test is given. A large number of test results show that,compared with the traditional methods,this method can effectively avoid the measurement error caused by single testing and the results have a higher credibility.