For some years, the IR laboratory of ONERA (France) carried out accurate electro-optical characterization on IR detectors. This paper presents some works about IR detector radiation hardness measurements: ONERA, in collaboration with DGA/CEG, measured the effects of gamma radiation on high wavelength IRCMOS. The test conditions respect hard constraints, particularly, during the radiation, detectors were cooled and operating. This paper reviews the implementation of these tests in very hard environment electromagnetic field, radiation, noise ...) and of a test protocol. In spite of severe environmental conditions, quality of measurement is comparable with those done in the laboratory. General component behaviors, transionnal and permanent effects, are summed up for very high dose rate.