Counter flow leakage detection with light trace gas in mass spectrometer detector

摘要

The method is carried out in a mass spectrometer leakage detector, the high vacuum pump of which is a combined turbo and HP molecular pump. The pre-vacuum pressure on the outlet side of the high vacuum pump is selected in the range between the limit pressure for the air or the nitrogen and the limit pressure for the light trace gas. The pressure is valid as limit pressure, with which the compression ratio of the high vacuum pump marked sinks for the associated gas. The test container is maintained at an inner pressure in the range named, if the trace gas is sprayed on it, from the outside. The shifting probe guided along the outside of the test container, which contains the trace gas, is so designed that the pre-vacuum pressure lies in the named region.