A unit of dose equivalent. The sievert has idential units to the gray and is arrived at by multiplying the absorbed dose by the quality EA( tor, a number that has been determined to accurately compare the health consequences of that type of radiation to x rays. The rem bears the same relationship to the rad as the sievert does to the gray.
A unit of absorbed radiation energy derived from SI units. One sievert is equal to 1 J/kg or 100 rem.