The residual gas analysis portion of the test system utilizes two different mass spectrometers: a quadrupole mass spectrometer capable of scanning the total abundance of gas over a broad mass range and a helium leak detector specifically tuned to mass 4 amu, which measures the flow rate of helium. The quadrupole mass spectrometer is a Pfeiffer HiQuadTM for analysis of neutral particles with a mass range from 1 to 340 amu. The scan speed is 0.125 ms to 60 s/amu, typically full scan time for a suite of gases (10 species) is on the order of 1–2 s. The mass filter utilizes 16 mm molybdenum rods for maximum selectivity, with a cross-beam ion source with tungsten filament for maximum sensitivity during dynamic measurements. A focusing dynode electron multiplier was used as the detector for maximum linearity over pressure ranges from 10−15 to 10−6 mbar.The minimum partial pressure detection limit for this instrumental configuration is 1×10−15 mbar.