Method for determining gas accumulation rates

A fluid seal comprising

• a cylinder having an interior wall, a first end, and a second end, the ends being open;
• a plug having a surface said plug disposed in said first end of said cylinder in such manner that a gap exists between the surface of the plug and the interior wall of the cylinder;
• a first seal disposed within said gap proximate to said first end, and a second seal disposed within said gap proximate to said second end, said seals, said wall, and said plug surface defining a volume;
• and,
• a means provided within said plug permitting introduction and removal of fluid within said defined volume.

An apparatus for testing gas permeability of plastic bottles, the apparatus comprising a fluid seal comprising:

• a cylinder having an interior wall, a first end, and a second end, the ends being open;
• a plug having a surface said plug disposed in said first end of said cylinder in such manner that a gap exists between the surface of the plug and the interior wall of the cylinder;
• a first seal disposed within said gap proximate to said first end, and a second seal disposed within said gap proximate to said second end, said seals, said wall, and said plug surface defining a volume;
• and,
• a means provided within said plug permitting introduction and removal of fluid within said defined volume.