Chop mode operated mass spectrometer for reducing the effect of line signals

摘要

The present invention provides a chop mode operated mass spectrometer that substantially reduces the effects of line signals on the operation of the mass spectrometer by admitting gas samples to the analyzer of the mass spectrometer at a frequency that is a sub-multiple of the line frequency. The signal output by the analyzer is sampled at a frequency that is a multiple of frequency at which the gas is being admitted to the analyzer and processed using a digital filter that results in the line signal being isolated from the signal or signals of interest.