Varian 979 Helium Leak Detector is capable of detecting leaks down to 10-9 atm-cc/sec. It has a built-in turbo pump and rotary vane foreline pump and is mounted on a portable cart with pneumatic wheels. In normal operation, the vacuum vessel under test can be evacuated solely by the leak detector. Helium can then be seeped around the outside of the vacuum system and is detected by the helium spectrometer if a leak allows helium gas to get inside the vessel. Depending on the size of the leak, the internal leak rate response time is between 0.5 to 979 seconds. This unit is also usable in sniff-testing mode for detecting leaks in systems pressurized with helium.
For rates information, please see the rates page.