A method of mass spectrometry is disclosed comprising setting an attenuation factor of an attenuation device to a first value and then separating or filtering ions according to a first physico-chemical property and separating or filtering ions according to a second physico-chemical property and obtaining a multi-dimensional array of data. The most intense ion peak within one or more subsets of the multi-dimensional array of data is determined. If it is determined that the most intense ion peak would cause saturation of an ion detector or ion detection system then the method further comprises adjusting the attenuation factor of the attenuation device to a second value and obtaining mass spectral data wherein the adjustment of the attenuation factor substantially alters the intensity of all ions which are detected by the ion detector or ion detection system equally and irrespective of the mass to charge ratio of the ions. The intensity of the mass spectral data is then scaled based upon the degree to which the attenuation factor of the attenuation device was increased or reduced.