ASTM F2096

Pressure Application

Submersion involves securing the specimen beneath a minimum of 25 millimeters of water within a transparent tank. A regulated air source introduces internal pressure to the package via a probe inserted through the barrier. Precise control of this pressure remains necessary because excessive force ruptures the seals while insufficient pressure fails to overcome the surface tension at the leak site.

Detection Limit

Sensitivity relies on the ability of the operator to observe a continuous stream of air bubbles originating from a single point. This visual verification makes the method a qualitative assessment of the seal rather than a quantitative measurement of leak rate. Most laboratories use a calibrated flow meter to ensure the air supply maintains the specific pressure required by the material thickness and porosity.

Material Exclusion

Porous materials like Tyvek require a period of saturation to prevent air from escaping through the natural interstices of the web. Failure to saturate the material causes false positives as air migrates through the entire surface. This method stops being effective when the defect size falls below the threshold where internal pressure can overcome the hydrostatic head and liquid surface tension.

If the packaging contains liquid contents, the internal pressure must be adjusted to account for the additional weight and viscosity.