Abstract
Resolution mode of quadrupole mass filter is well represented by mass scan line on stability diagram. All mass peaks just disappear on the cutoff scan line which passes through the origin and to the apex of the stability diagram. When a scan line is shifted downward by a small amount parallel to the cutoff scan line, it can be expected theoretically that all mass peaks give a constant peak width independent of mass. Adjustment of resolution is carried out based on this theory. As peak height is proportional to the peak width, a mass spectrum obtained experimentally with this mode of operation gives a constant pattern coefficient in adjusting the resolution.
