Abstract:
A static expansion method is performed by expanding a volume of a testing gas from V0 to V0+V1 between a second chamber of the volume V1 which is connected to an upstream side of a measurement chamber and a first chamber of the volume V0 which is connected to an upstream side of the second chamber, wherein the first camber is in communication with the second chamber via a first valve, wherein the second chamber is in communication with the measurement chamber via each of a second valve and an orifice or porous plug, respectively. When the first valve is opened and the second valve is closed, the testing gas flows from the first chamber via the second chamber into the measurement chamber only through the orifice or porous plug.
Abstract:
There is provided a reference leak generating device capable of precisely generating an ultra-fine reference leak. The reference leak generating device adapted to be connected to an upstream side of a measurement chamber includes a chamber connected to the measurement chamber through an orifice or a porous plug having a molecular flow conductance C and a pressure to establish molecular flow conditions which are known in advance, and is characterized in that a pressure p1 of testing gas to be introduced into the chamber is precisely determined by using a static expansion method once or more times, and a leak rate of a reference leak at the pressure p1 is obtained in accordance with a product of C and p1.