The amount of radiation an object (such as human tissue) receives. Several units are used to describe radiation doses:
- rad (acronym for radiation absorbed dose) -- a basic unit of the amount of radiation absorbed by body tissue. The rad largely has been replaced by the gray measurement scale.
- gray (abbreviated Gy) -- the newer, international unit of measurement of radiation absorbed. One gray equals 100 rads.
- rem (acronym for roentgen equivalent man) -- -- a conventional unit of radiation exposure used to express the chance that a person will have health effects based on both the dose and the type of radiation. The term has been replaced by the sievert.
- sievert (see-vert) -- abbreviated Sv. The newer, standard international unit of radiation exposure used to express the chance that a person will have health effects based on both the dose and the type of radiation. One sievert equals 100 rem.