Sievert (Sv): The SI unit of radiation dose equivalent or
equivalent dose. It is equal to the dose in gray times a quality factor (Q) or
radiation weighting factor (wR): 1 Sv = 100 rem
Radiation weighting factor (wR): A
factor used for radiation protection purposes to allow for differences in the
biological effectiveness between different radiations. These factors are
independent of the tissue or organ irradiated.