radiation units

RADIATION UNITS



Roentgen



The roentgen ® is defined as a unit of radiation exposure that will liberate a change of 2.58 x 10-4 Coulombs per kilogram of air.





Rad



The rad is the unit of absorbed dose. One rad is equal to the radiation necessary to deposit energy of 100 ergs in 1 gram of irradiated material.

Gray (Gy) is the SI unit for absorbed dose

1 Gy = 100 rads

1 rad = 1 c. Gy (Centigray)





Rem



The rem is a unit of absorbed dose equivalent. The rem is a unit used only in radiation protection.

The rem is a measure of the biological effectiveness of radiation.

SI unit of absorbed dose equivalent is Sievert.



1 Sievert (Sv) = 100 rems

Rem = Rads x Quality factor

B/ c the quality factor for Xray is 1 , therefore diagnostic energy levels.

1R = 1 rad = 1 rem