Helium is one of the smallest gas molecules and because it is inert, helium is safe to use instead of hydrogen and will not react to any parts of the materials that are being tested. A helium mass spectrometer is an instrument we use for the small and extremely difficult leaks. Initially developed during World War II, this instrument uses a vacuum chamber in which a sealed container with helium is placed, helium then leaks out of the container, and then the rate of the leak is detected by a mass spectrometer.
Helium is used as a tracer gas penetrating small leaks rapidly. By inserting helium in the line, CPL can pinpoint a leak with a sensitivity reading as low as 22 parts per million (PPM). We have filled pipes as large a 60” with helium to locate tiny leaks and have experience great success statewide.
By using this technique, we are able to find smaller leaks which are extremely difficult to locate. This is also useful when it comes to loud environment. We have found that this technique also worked well with small gas leaks provided that the gas has already been turned off.