METHOD TO TEST TIGHTNESS OF LARGE-SIZE SPACECRAFT UNDER ATMOSPHERIC CONDITIONS Russian patent published in 1997 - IPC

FIELD: testing equipment. SUBSTANCE: spacecraft of volume Vart is put into closed shell of volume Vsh. Shell is communicated with additional vessel before placement of spacecraft into it, additional vessel is filled with air from closed shell. After placement of spacecraft closed shell and additional vessel are isolated. Spacecraft is filled with check gas containing trial gas with concentration Cart up to working pressure. Time delay is maintained during accumulation Tn in the course of which n determinations of increment of concentration of trail gas in closed shell are conducted. With i-th determination (i=1, 2, 3..., n) output signals A1i and A2i of leak detector are measured from standard concentrations C1 and C2 of third gas in air correspondingly, Aui from air contained in closed shell, Aoi from air contained in additional vessel. Determination of increment of concentration of trial gas ^Ci in closed shell at present time moment t_i is carried out by formula . After h-th determination of increment of trial gas in closed shell lack of tightness Qart of spacecraft is evaluated by formula . EFFECT: increased accuracy of test of tightness of large-size spacecraft under atmospheric conditions.