ASTM E 499 - 95. Standard Test Methods for Leaks Using the Mass Spectrometer Leak Detector in the Detector Probe Mode

American Society for Testing and Materials (ASTM). 1995, 6 pages.
These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 3 10−13 mol/s (1 3 10−8 Std cm3/s)3 or greater. The test may be conducted on any device or component across which a pressure differential of helium or other suitable tracer gas may be created, and on which the effluent side of the leak to be tested is accessible for probing with the mass spectrometer sampling probe.