1.1 These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 x 10 13 mol/s (1 x 108 Std cm 3/s) 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.1.2 Two test methods are descr