Automatic voltage scanner for a peak switching mass spectrometer

Abstract

An automatic voltage scanner for the rapid determination of appearance potentials has been developed for the AEI MS9 mass spectrometer. The peak-matching circuitry of the MS9 normally used for precise mass measurements is utilized in this system. As a result, this system also identifies the species of interest. The ionizing voltage may be scanned in 0.2 or 0.05 v increments from 70 to 3.5 ev with this modification. The recorder output automatically displays two ionization efficiency curves: that of the reference material of known ionization potential which serves to calibrate the voltage scale and that of the sample whose appearance potential is to be measured.