Abstract: A dose measurement system for ion implantation equipment based on the thermal energy deposited by the ion beam on a calibrated mass which periodically intercepts the beam. The method is insensitive to the ambient electrons which are present in the ion implanter volume. The method is also independent of processes in which the energetic ion changes its charge along its beam path. Thus, the invention solves problems of conventional does measuring system based on charge collection requiring exclusion of free electrons from the collector and compensation for the component of the implanted beam which is un-ionized and hence unrecorded by the charge collector. The simplicity and compactness of the calorimeter method has further advantages, in particular, the calorimeter solves the problem of making dose measurements in restricted spaces.