A method of verifying the integrity of the walls and seals of a sealed container is provided in which a low molecular weight gas is introduced into the interior of the container before the container is sealed. After sealing, the container either alone, or in batches with others, is placed into a chamber...http://www.google.com.au/patents/US5345814?utm_source=gb-gplus-sharePatent US5345814 - Method and apparatus for testing vacuum insulation panel quality
