The TOF acquisition mass range depends on the maximum pusher interval and pusher pulse width. For QTof instrumentation this limits the mass range to 20-30 kDa, depending on the instrument generation. The high mass upgrade package multiplies both the pusher interval and the pusher pulse width by a user-selectable factor, shifting the theoretical maximum TOF mass range into the megadalton region. These modifications go unnoticed by the software, just enter the mass range and start acquiring.
Mass spectrum of three different capsid types of Hepatitis B virus. Data is acquired well over the normal m/z cutoff at 33kDa. The captions represent molecular masses. Figure taken from Uetrecht et al, High-resolution mass spectrometry of viral assemblies: Molecular composition and stability of dimorphic hepatitis B virus capsids, PNAS July8, 2008 vol.105 no.27 p9216–9220.
