scope:

The determination of quantities relevant to radiation protection often entails significant uncertainties, and approximations will need to be introduced. However, it is essential that the quantities employed be unambiguously defined, and that the approximations be clearly identified. ICRU Report 51 aims to provide, in a revised format, a single clear presentation of a coherent system of quantities and units for use in radiation protection dosimetry. It is intended for purposes of measurement and calculation in the assessment of compliance with dose limitations. Thus, the report is divided into two parts. Part I deals with the quantities and units defined for use in measurements and calculations, whereas Part II relates to quantities based on mean values which are used for limitation purposes.