Finding Pinhole Leaks With High Voltage
Posted: Sun Jan 03, 2010 2:45 pm
We routinely vacuum leak checked our condensers which operated under a vacuum using helium and a helium leak detecter. The procedure involved injection of helium using "cake pans" to limit surface exposure to small areas we were checking for leaks. If a vacuum leak existed at the injection site (isolated by the "cake pan"), helium would be sucked into the vacuum chamber through the leak and picked up by the vacuum pumps and exhausted. The helium leak detecter was piped up to the vacuum pump exhaust and would pull a gas sample for the instrument to detect. We started this in the early 1980's and it is still the method used today. The helium leak detecters have been improved greatly since we started. I would presume the Navy uses a similar method to check their condensers for vacuum leaks.
Regarding the sited device, it looks like the high voltage pin hole detecter assumes a nonconducting liner has a defect that is being sought. I am not sure of the polywell application. I am likely missing the point here...