Hi A mil standard leak test works like this:
First you run a bubble leak, generally in something like hot synthetic oil. If the leak is too big, you will not catch it with a helium test. Next you put the parts in a pressure vessel and pressurize it with helium (or possibly a gas mix). How high a pressure and how long depend a bit on just what you are testing. After they have soaked for a while, you de-pressurize and let the residual gas on the surface of the parts fly away. That does not take long at all. The go into a mass spectrometer and get pumped down while it looks for an outflow of helium. A flow above a certain level means it’s a failure. What that level is depends on the spec on the part and it’s size. Many thousands of parts get tested this way every (working) day of the year. Bob > On Nov 1, 2018, at 2:40 PM, Hal Murray <[email protected]> wrote: > > > [email protected] said: >> Helium leak testing is a *very* common thing in the oscillator industry. I’d >> bet it also is done in the MEMS oscillator business as well. > > How does that test work? > > It seems obvious how to test stuff that is designed to hold Helium - put the > Helium in and sniff the surrounding air to see if any leaks out. But how do > I > test a small package to see if any leaks in? > > Maybe give it a chance to leak in for a while and then see if any leaks out? > > > -- > These are my opinions. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
