METHOD OF DETERMINING AIR-TIGHTNESS OF ARTICLES OPERATING UNDER EXTERNAL PRESSURE

FIELD: test equipment.SUBSTANCE: invention relates to the field of testing of devices for air-tightness and can be used for determination of tightness of the articles operating under external pressure, in particular space equipment articles. Essence of the invention: an internal cavity of an article is evacuated through the testing system down to steady-state equilibrium pressure in a product and the testing system.. An article is disconnected from the testing system, while continuing evacuating the testing system. The first steady-state equilibrium pressure in the testing system is measured that corresponds to inflow into the testing system of own flow of gas separation and a leakage of the testing system. The calibrated leak is connected to the testing system. The steady-state equilibrium pressure in the testing system is measured that corresponds to inflow into the testing system of own flow of gas separation and a leakage of the testing system and gas flow from the calibrated leak. The calibrated leak is disconnected from the testing system. The article is connected to the testing system. The steady-state equilibrium pressure corresponding to inflow into the testing system of a flow from the article leakage and own flow of gas separation and leakage of the testing system is measured. The article is disconnected from the testing system. The second steady-state equilibrium pressure is measured that corresponds to inflow into the testing system of own flow of gas separation and a leakage of the testing system. The level of leakage of the article is determined on the basis of the value of gas flow from the calibrated leak and values of the named pressure. Meanwhile after pumping out of an internal cavity of the article through the testing system until the steady-state equilibrium pressure in the article and disconnection of the testing system and the article from the testing system the testing system section with the known volume which is interconnected with the calibrated leak is disconnected from evacuation devices. And the calibrated leak is connected to the testing system section with the known volume. Gas flow from the calibrated leak is measured by the rate of pressure rise formed it in the testing system section of known volume. The calibrated leak is disconnected from the testing system section with the known volume. After that the testing system section with known volume is connected to the evacuation devices and the cooled trap of the evacuation