ISO/ASTM 51275:2013 is a practice for using radiochromic film dosimetry systems to measure absorbed dose in materials irradiated by photons or electrons in terms of absorbed dose to water. Radiochromic film dosimetry systems are generally used as routine dosimetry systems. The radiochromic film dosimeter is classified as a Type II dosimeter on the basis of the complex effect of influence quantities. ISO/ASTM 51275:2013 is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ASTM E2628 for a radiochromic film dosimetry system. It is intended to be read in conjunction with ASTM E2628.