Inficon UL Fab 1000 repair

Inficon Fab UL1000 Helium Leak Detector, with the use of time pass, the following conditions may be occured

The  detection time of Inficon Fab1000 is getting longer and longer, and the pressureof the test port goes down slowly than before. Possible reasons 1. There is a problem with the vacuum pump, 2. The vacuum gauge is inaccurate 3. The internal vacuum parts are leaking 4. The mass spectrometer chamber is dirty
Inficon Fab1000, the helium background value before leak detection, goes up  and down, the possible reasons are as follows: 1. Inficon UL1000 mass spectrometer chamber or pipeline is contaminated. 2. The space you leak detection in a closed room 3. The vacuum pipe inside Fab1000 is leaking