This part of IS0 4037 specifies the characteristics and production methods of X and gamma reference radiation for calibrating protection-level dosemeters and rate dosemeters at air kerma rates from 10 pGy.h-l to 10 Gy.h-1 and for determining their response as a function of photon energy. The methods for producing a group of reference radiations for a particular photon- energy range are described in four sections which define the characteristics of these radiations.