This International Standard has been prepared by IEC/SC 62C "Equipment for radiotherapy, nuclear medicine and radio dosimetry". This standard specifies the performance and some related constructional requirements of diagnostic dosimeters intended for the measurement of air kerma, air kerma length product or air kerma rate, in photon radiation fields used in radiography, including mammography, radioscopy and computed tomography, for X-radiation with generating potentials not greater than 150 kV. The requirements for the accuracy of diagnostic dosimeters in this standard are of fundamental importance for compliance with the requirement for the lowest possible patient dose with sufficient image quality of diagnostic X-ray equipment, in particular according to Section 16 of the German X-ray Ordinance (RöV). This standard does not deal with the safety aspects of dosimeters. The diagnostic dosimeters to which this standard applies are not intended for use in physical contact with the patient. The electrical safety requirements applicable to them are contained in IEC 61010-1. NA 080-00-11 GA NAR/DKE Joint Working Committee "Dosimetry" of the Standards Committee Radiology (NAR) at DIN Deutsches Institut für Normung e. V. is responsible for this standard in collaboration with the Deutsche Röntgengesellschaft (German Radiological Society) and DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE and in cooperation with the Deutsche Gesellschaft für Nuklearmedizin e. V. (DGN) (German Society of Nuclear Medicine), Deutsche Gesellschaft für Medizinische Physik e. V. (DGMP) (German Society for Medical Physics) and Deutsche Gesellschaft für Radioonkologie e. V. (DEGRO) (German Society for Radio Oncology).