Reference leakage device (1) for use in leakage detection of gas, comprises a membrane (5) adapted to be interposed between two environments having respective pressures pu and pa, where (I). The membrane has an orifice (6) adapted to determine a controlled gas flow depending on the pressure pu. The orifice has a preset diameter D and length L such that (II). The diameter D and the length L are further dimensioned in such a manner that the equivalent diameter De of the orifice is De≦100 nm, where De is defined by the relation De=D.a1/2 wherein a is the transmission probability of the orifice, function of the L/D ratio. The orifice is adapted to operate in molecular flow regime in an entire range of pυ values comprising the value of atmospheric pressure.
REFERENCE LEAKAGE DEVICE FOR LEAK CALIBRATION
FIRPO, GIUSEPPE;REPETTO, LUCA;VALBUSA, UGO
2008-01-01
Abstract
Reference leakage device (1) for use in leakage detection of gas, comprises a membrane (5) adapted to be interposed between two environments having respective pressures pu and pa, where (I). The membrane has an orifice (6) adapted to determine a controlled gas flow depending on the pressure pu. The orifice has a preset diameter D and length L such that (II). The diameter D and the length L are further dimensioned in such a manner that the equivalent diameter De of the orifice is De≦100 nm, where De is defined by the relation De=D.a1/2 wherein a is the transmission probability of the orifice, function of the L/D ratio. The orifice is adapted to operate in molecular flow regime in an entire range of pυ values comprising the value of atmospheric pressure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.