Improved method of data dependent control

A method of mass spectrometry is disclosed comprising obtaining first data at a first time and/or location and second data at a second subsequent time and/or location. A future trend or rate of change in the data is predicted from the first and second data. An attenuation factor of an attenuation device is adjusted in response to the predicted future trend or rate of change in the data so as to maintain operation of a detector or detector system within the dynamic range of the detector or detector system and/or to prevent saturation of the detector or detector system.