Vacuum Decay is the primary leak test method for full container inspection, including seal integrity testing and/or container integrity testing. Vacuum Decay can also be used for testing Empty Containers that require a minimum vacuum level.
ALPS Vacuum Decay leak test curve example
The standard Vacuum Decay leak test works the same as Pressure Decay with the exception that a Vacuum is applied to the test volume instead of Pressure. (Pressure Decay terms are often used interchangeably).
For full container inspection and seal integrity testing, the Vacuum Decay tester typically performs a four step process:
- The Vacuum Decay tester creates a test volume outside the full container, typically around the seal for purposes of seal integrity testing.
- The Vacuum Decay tester evacuates the test volume to the desired vacuum. If the target vacuum range is not achieved within a pre-defined time the product fails as a "gross leak." If the vacuum is achieved, the Peak value is recorded.
- The Vacuum Decay tester measures the vacuum drop from the Peak to a defined initial Time (T1). T1 can be used as stabilization time for flexible containers when longer test times are available. The product is rejected if the vacuum drops beyond a pre-defined limit.
- The Vacuum Decay tester measures the vacuum drop from T1 to the end of the test (T2). The product is rejected if the vacuum drops beyond a pre-defined limit. This final test offers detection of the smallest leaks.