REFERENCE LEAKAGE DEVICE FOR LEAK CALIBRATION

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.