Inside-Out Go-No-Go Testing
The component to be tested is pressurized with test trace gas, typically Helium, either pre-charged and inserted in a vacuum chamber or charged during evacuation. Any leak in the system will allow the trace gas to leak into the vacuum chamber where it will be detected by the leak detector.
This is the preferred test technique for a number of reasons!
The technique provides the greatest pressure differential between the trace gas source and detector (pressurized gas to detector under vacuum) which provides the fastest response and highest sensitivity to a given leak. Automation of the test cycle is very easy and a Go-No-Go measurement is made making this an ideal solution in the production environment. If a leak is present, however, this technique will not locate the leak site.
