Apparatus & Materials
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.
1.1 This test method covers the determination of gross leaks in flexible packaging containing a headspace gas. Test sensitivity is limited to 1 × 10−5 atm cm3/s (1 × 10−6 Pa m3/s) or even less sensitive as indicated in a recent interlaboratory test (reported in Section 12).
1.2 Small leaks may not be detected by this procedure. Viscoelastic effects on the products, or entrapped air, become significant and prevent passage through small openings. Positive pressure inside the pouch after the vacuum is drawn may force the product to plug small leaks. The size of the leak that can be detected is dependent upon the products contained, the nature of the packaging material, and the test parameters selected.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.