In preparation of space-change studies a MagneTOF detector is evaluated for bunches with a wide range of ion numbers. The detector is calibrated based on the comparison between single-ion counting and ion-bunch-signal integration. This allows to determine up to several ten thousands of ions in a bunch with a FWHM of about 700ns, the integrated signal of which increases linearly with ion number. Furthermore, this detector limit can be circumvented using transmission-limiting elements in front of the detector. Based on this, ion bunches are investigated up to several million ions, which are prepared with a linear Paul trap. Thus, in addition to the MagneTOF detector this trap is characterized with respect to its space-charge limits at low potential-well depth.