Radiation Quantities and Units
RAD and Gray - Units of Absorbed Dose

back (1K)       next (1K)

Radiation Quantities and Units


  • Exposure (Roengten) only measured dose in air from x-rays and gamma rays.
  • Other measurement quantities and units were developed that would measure radiation damage in any materials for any type of radiation (e.g., alpha or beta).
  • This unit was termed Absorbed Dose and is the energy absorbed per unit mass of material.
  • Two different units are used:
    • Rad - 1 Rad = 100 ergs/gram (The Rad is the traditional unit used in the USA)
  • Gray (Gy) - 1 Gy =1 Joule/kilogram = 100 rad (The Gy is the SI (International System of Units) unit used by most countries and used in almost all literature).


    • Page 82

    back (1K)       next (1K)