METHOD OF CONTROLLING TIGHTNESS OF ARTICLES Russian patent published in 2016 - IPC G01M3/02 

FIELD: test equipment; gas industry.

SUBSTANCE: invention relates to methods of controlling tightness of articles containing test (working) gas (substance). Summary: closed cover with the product is evacuated to specified pressure. Accumulation of probe (working) gas leaking from product is carried out, in volume of closed shell. Pumped out volume of vacuum system with mass-spectrometer sensor for detecting leakages during accumulation of probe (working) gas in volume of closed shell. Pumping from vacuum system to sensor of mass-spectrometer for detection of leaks of probe (working) gas is stopped directly before bypass of accumulated portions into it. With pumping out of all other gases, except for probe (working) gas, bypass of accumulated gas portion is performed into vacuum system with mass spectrometer sensor. Mass-spectrometer sensor signal corresponding to concentration of test (working) gas is continuously recorded. Exposure is performed until linear increase of concentration signal is achieved. Approximation of linear sections corresponding to background and signal is performed by least squares method. Finding difference between total and background concentrations of probe (working) gas at beginning of portion bypass. At that, series of measurements of intensities of peaks of mass spectrometer analytical signal is performed, repeating all control jobs and producing of pumping out volume of vacuum system with mass-spectrometer between measurements until initial values of background concentrations are achieved. At that, mass spectrometer is tuned to preset weight number and its signal is proportional to value of leak flow of probe (working) of gas from article in time. One performs approximation of obtained current values of leakage flows using mathematical techniques with further extrapolation at exposure gap, which relate to zero moment of time (t = 0 is moment before article sealing). Value of approximation function leak flow in this point (at this moment) is determined. Using derived value degree of leakage from articles is determined.

EFFECT: higher accuracy of tests results.

1 cl, 5 dwg