A method for linearizing a radiation detector is provided, the method including measuring a pulse height spectrum of a predetermined radiation source, identifying at least one spectrum template for the predetermined radiation source, and determining a linearization function by comparing the measured pulse height spectrum with the at least one identified spectrum template. The at least one spectrum template is a predefined synthesized energy spectrum for the predetermined radiation source and for the corresponding radiation detector. Further, a detector for measuring one or more types of radiation is provided, the detector being adapted for transforming the measured pulse height spectrum in an energy-calibrated spectrum, the transformation including a linearization step, where a linearization function used with the linearization step is determined according to the inventive method.