Measurement of position‐dependent detection efficiencies for two quadrupole mass spectrometers with electron‐impact ion sources

摘要: Measurements have been carried out of the position‐dependent detection efficiencies two quadrupole‐type commercial mass spectrometers with electron‐impact ion sources. Contours constant for different source parameters were determined by scanning a collimated argon beam 1‐mm diameter across source. The measured results show clearly how settings influence efficiency and size active volume within Furthermore it is found that optimal performance instrument in molecular‐beam mode as well residual gas occurs at same settings. absolute value efficiency, this particular setting, Dmax = 0.88 × 10−5. A simple model developed connecting conventional sensitivity factor contour plots. agreement between calculated factors good.