The ASTM-D3078 is the standard test method for determination of gross leaks in flexible packaging containing a headspace gas by bubble emission. The test is conducted by submerging the test specimen in the immersion fluid within the confines of a vacuum chamber. If bubbles or seepage of fluid within specimen attributable to a leak are observed, then the specimen fails the test.
Vacuum Chamber: A vacuum chamber shall be any transparent container capable of withstanding approximately one atmosphere pressure differential, fitted with a vacuum-tight cover. A vacuum gage, an inlet tube from a source of vacuum, and an outlet tube to the atmosphere shall be connected to the chamber cover.
Immersion Fluid: Use an immersion fluid which does not degrade the package being tested. The test sample and test fluid shall be at equilibrium with normal room temperature.