Patent ID: 8084736

Claim:
A mass spectrometer system comprising: a differential mobility spectrometer for receiving ions from an ion source, the differential mobility spectrometer having an internal operating pressure, electrodes, and at least one voltage source for providing DC and RF voltages to the electrodes; a mass spectrometer at least partially sealed to, and in fluid communication with, the differential mobility spectrometer for receiving the ions from the differential mobility spectrometer; a vacuum chamber surrounding the mass spectrometer for maintaining the mass spectrometer at a vacuum pressure lower than the internal operating pressure, the vacuum chamber having a vacuum chamber inlet and being operable to draw a gas flow including the ions through the differential mobility spectrometer and into the vacuum chamber via the vacuum chamber inlet; and, a gas port for modifying a gas flow rate through the differential mobility spectrometer, the gas port being located between the differential mobility spectrometer and the mass spectrometer.