DFMS is a high resolution mass spectrometer. The instrument´s design is based on reliable design concepts which were optimized for mass resolution and dynamic range using modern ion optics optimization methods. Thereby, a resolution greater than m/Δm = 3000 (at 1% peak height), a high dynamic range, and a high sensitivity are achieved. DFMS has two basic operation modes: a neutral gas mode and an ion mode. Switching between the neutral and the ion mode requires a change of a few potentials in the ion source and suppression of the electron emission that is used to ionize the neutral gas particles. All other operations are identical for the two modes.
DFMS achieved or even surpassed the specifications. Especially, it was possible to extend the mass range during the mission from 100 Da to 180 Da.