Volumetric Fill Leak Testing for Sealed DevicesVolumetric Fill is a leak test method used to test sealed parts for compliance with industry and manufacturing standards. This two-step leak test involves performing a gross and fine leak test on the test part.
Sealed devices cannot be tested using conventional pressure or vacuum decay testing because they are ‘sealed’ and do not have ports to apply pressure or vacuum to test for leaks. The volumetric fill leak test provides a reliable alternative that complies with IP67 leak test standards.
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What is the Process for Sealed Device Leak Testing?To test a sealed device the part is placed inside a sealed chamber and the leak test is conducted on the air or space inside the chamber surrounding the outside of the part and test for air being forced inside the part or for air to escape the part. The gross leak test stage of the volumetric fill test will make sure there are no gross leaks in the part prior to conducting the fine decay leak test.
Without a volumetric IP67 leak test, you could fill up the volume of a gross leaking part during the fill stage of the test and never be able to check for a small leak because there wouldn’t be an air pressure differential on the part chamber.
Using Gross Air Leak Testing for IP67 ComplianceIP67 leak tests provide manufacturers and consumers reassurance that their sealed devices meet requirements for protection against dust and moisture ingress. To meet these standards, sealed devices must resist dust exposure and withstand submersion in up to 40 inches of water for 30 minutes.
First, the Volumetric Fill introduces a known reference volume into the test circuit and uses equalization of a known pressure to accurately measure the leak. If the part has a gross leak the test would not meet the ‘target pressure window’ specification and fail the gross leak test. If the passes the gross leak test the program automatically performs the fine pressure decay leak test.
See the diagram below for an example of the sealed device leak testing process.
Understanding Reference Volume in Sealed Device Leak TestingImagine the volume of your reference air tank being the same of the volume of the free space of the chamber surrounding the outside of the part and neglect all the tubing and inefficiencies. If the reference volume, which is 5 psig in our example, is allowed to flow into the test chamber with a good part then the equalized pressure would be around 2.5 psig.
If there was a gross leak in the part and the part was the same volume as the reference tank, then the new pressure would be 01.25 psig and the test would fail. If the part passes the gross leak test a ‘fine’ pressure decay leak test is performed on the part.
Performing a Volumetric Fill leak test on ‘seal parts’ ensures your parts are leak-tight and conform to IP67 ingress contamination standards.
Learn About Our Gross Air Leak Test SolutionsCTS designs and manufacturers multifunctional systems for sealed device leak testing. We offer a broad portfolio of leak detection instruments and have over 30 years of experience serving customers across the globe. Use our systems for IP67 leak tests or any other leak testing application aimed at ensuring product reliability and quality.
Contact us to discuss available solutions for gross air leak testing.