Helium Mass Spectrometry Principles for Battery Seal Hermeticity Testing
Helium mass spectrometry isolates sub-micron battery seal defects down to 10-12 mbar·L/s, preventing field electrolyte drying and moisture ingress.
Tracer Gas Testing
Meaning
Leak detection technique that uses a specific gas to identify and quantify the leakage of a sealed system. Helium is the most common medium for tracer gas testing because of its small molecular size and low atmospheric concentration. It allows for the detection of leaks that are too small for liquid immersion methods.
Detection Medium
Choice of gas depends on the sensitivity required and the background levels present in the facility. While helium is standard, tracer gas testing can also utilize hydrogen or nitrogen depending on the safety constraints of the production environment.
Test Procedure
Detection limits can reach levels as low as ten to the minus twelve standard cubic centimeters per second. During tracer gas testing, the component is either pressurized with the gas or placed in a vacuum chamber. The method chosen depends on whether the goal is to find a specific leak point or to certify the total integrity of the seal.
For large battery packs, a vacuum chamber method is preferred because it eliminates the interference of background gases. It also provides a repeatable environment for high precision measurements across different production batches.
System Sensitivity
High volume manufacturing lines use automated vacuum chambers for rapid verification of battery housing integrity. This tracer gas testing ensures that every pack meets the ingress protection requirements before installation. It prevents the shipment of units that could be vulnerable to moisture penetration or internal fluid leaks.