What Is Sealed Device Leak Testing?
Sealed device leak testing is a method of leak testing “sealed” products that don’t have ports, valves, or any other way to apply pressure or vacuum for testing purposes. A dry and nondestructive test process, it is an effective way of ensuring that sealed products truly are sealed against contamination and leakage, and is especially important for parts that require IP67 classification.
How Does Sealed Device Leak Testing Work?
The best way to leak test your sealed products is via volumetric fill testing using Cincinnati Test Systems’ Sentinel I28 leak test instrument. To perform this type of test, the sealed device is first placed in a test chamber. The chamber is sealed, and air or vacuum is used to charge the chamber to the required test pressure. The Sentinel I28 unit monitors pressure changes inside the test chamber, with changes in pressure used to measure leak rate to determine the pass/fail condition of the part in test.
Any change in pressure indicates that either the object under test is leaking air into the chamber (if under vacuum) or that air from the chamber is infiltrating the object (if using pressurized air). If the pressure change is less than the tested product’s leak rate specification, the product passes the test; if the pressure change is greater than the specification, the product has failed.
Gross Leak Testing vs. Fine Leak Testing
Sealed devices can be tested using two different processes: gross leak testing and fine leak testing. In gross leak testing, air travels into the test chamber via the chamber’s isolation valve, and pressure is equalized between the chamber and the reference volume tank. Gross leak testing provides almost immediate results.
If a sealed device passes the gross leak test, it can then undergo fine leak testing. A fine leak test measures pressure loss in the test chamber over an extended period of time. The test chamber’s isolation valve is closed, and pressure inside the chamber is monitored for gradual loss. If the pressure drop over the programmed test time does not exceed part specifications, the part has passed the test.
Our Sentinel I28 leak test system can be used for both gross leak testing and fine leak testing, and can be programmed to perform both tests consecutively for fast, complete sealed device leak testing.
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