Research on leakage detection method of vacuum chamber flange in space environment simulation system under atmospheric pressure

To address the issue of the irreversible process once a leakage is detected in the vacuum chamber flange of the current spacecraft space environment simulation system after the rough pumping stage, this paper researches the leakage detection method of vacuum chamber flange under atmospheric pressure, that is, without pressure difference between inside and outside the chamber. Based on the principle of sound generation due to pressure difference at the leakage hole, an ultrasonic leakage detection system under atmospheric pressure is established. The detection capability for leakages caused by different-sized materials is studied, and millimeter-diameter steel wire inclusions are successfully detected. Combined with the helium mass spectrometry leakage detection method and limit leakage rate test method, the critical sound pressure level that affects the vacuum degree of the chamber is given to achieve early discovery, intervention, and elimination of chamber leakage failures.