Leybold UL 200 Helium Leak Detector

The Leybold UL 200 Helium Leak Detector is capable of detecting and quantifying helium test gas flowing into a test sample having a leak by means of a selective mass spectrometer. Its operation is based on the counter flow principle, i.e. inflowing helium diffuses against the gas flow being pumped by the turbomolecular pump into the mass spectrometer whereas heavier gases, water vapor in particular, are held back. A cold trap using liquid nitrogen is thus not required.