Leak testing: moving beyond the most popular methods

Helium has been the most commonly used tracer gas for leak testing. This is simply due to the fact that helium is the lightest of the inert gases and Helium mass spectrometers are extremely sensitive to trace amounts of this gas. Mass spectrometers, commonly used to analyze unknown gases, and recently gaining some notoriety for their Martian mineral-testing application, have also been developed for leak testing applications.