Sievert

High Quality Content by WIKIPEDIA articles! The sievert (symbol: Sv) is the SI derived unit of dose equivalent. It attempts to reflect the biological effects of radiation as opposed to the physical aspects, which are characterised by the absorbed dose, measured in gray. It is named after Rolf Sievert, a Swedish medical physicist famous for work on radiation dosage measurement and research into the biological effects of radiation. The equivalent dose to a tissue is found by multiplying the absorbed dose, in gray, by a dimensionless "quality factor" Q, dependent upon radiation type, and by another dimensionless factor N, dependent on all other pertinent factors. N depends upon the part of the body irradiated, the time and volume over which the dose was spread, even the species of the subject.