LEAKAGE TEST METHOD Russian patent published in 1995 - IPC

FIELD: leakage testing. SUBSTANCE: article is placed into chamber which is pumped out till achieving pressure of 1·10^-1-1·10^-3mmHg (13.3-0.133 Pa) by means of exhaust and additional pumps. Technological gas flux is fed into the chamber to improve pressure in cavity of the chamber to value which exceeds 10-20% lower pressure limit which corresponds to maximal rate of exhaustion of additional pump. Helium standard flux is fed into chamber, when controlling preliminary additional exhaustion till achieving time of stabilization of partial pressure of helium in vacuum chamber after the standard flow is fed into the chamber during 10-20 minutes. Article is filled with check gas till reaching test pressure and leakage is evaluated according to relation of signals indicated. Pump-in of technological gas permits to wide range of control of additional pumping and to improve rate of change signals detected by leak detector due to the fact that additional exhaust pump starts to operate at maximal pump-out mode. EFFECT: improved efficiency; widened range of control. 1 dwg