Ionizing Radiation Units

Ionizing radiation is the flow of elementary particles that have sufficient energy to cause ionization of atoms and molecules in the irradiated substance.

The absorbed radiation dose

In the international SI system, to measure the effect of radiation on a substance, measure the absorbed dose, which is defined as the absorbed energy per unit mass.
  The unit of absorbed dose of SI is Gray [Gy].

• 1 Gy = 100 rad = 1 J/kg = 1000 mGy.
• 1 milligrey[mGy] = 1000 microgrey [μGy].
• 1 centigree [cGy] = 10 mGy.
• 1 rad (unit of absorbed dose) = 1 cGy.

Exposure dose of radiation

To determine the exposure dose of ionizing radiation, use an X-ray unit [R].

• 1 X-ray [R] = 1000 milli-roentgen [mR].
• 1 milli-roentgen [mR] = 1000 microroentgen [μR].

Equivalent dose of radiation

The equivalent dose of radiation is measured in Sievert and Baer.
  Sievert [Sv] is a SI unit.

• 1 Sievert [Sv] = 100 Baer.
• 1 millisievert [mSv] = 0.1 Baer.
• 1 millisievert [mSv] = 1000 microsievert [μSv].