A collision cell has a plurality of rod electrodes arranged in opposed pairs around an axial centerline and a plurality of drag vanes arranged in the interstitial spaces between the rod electrodes. Operating the collision cell includes, applying a rod offset voltage to the rod electrodes, and varying an offset voltage applied to the drag vanes to identify a vane offset voltage with a maximum intensity for the transition. The method further includes varying a drag field by adjusting the voltages applied to drag vane terminals in opposite directions to identify a drag field value with a cross talk below a cross talk threshold, varying the vane offset voltage by adjusting the voltages applied to the drag vane terminals to maximize the intensity of the transition while preserving the drag field, and operating the collision cell at the vane offset voltage and drag field to monitor the transition.