Short for roentgen equivalent man, the unit of equivalent and effective dose used in US regulation and plant practice: 1 rem equals 10 millisieverts. Workers and RP technicians speak in millirem, so a dose rate of 5 mrem per hour, a job dose of 20 mrem and an annual administrative limit of 2,000 mrem are everyday figures. Its absorbed-dose partner is the rad, equal to 0.01 gray.
Job's estimated at 35 millirem per person, the RWP alarm is set at 50.
Mixing millirem and millisievert in one report is a classic error; one millisievert is 100 millirem.
Also heard as
- roentgen equivalent man
Related terms
Sievert
The SI unit for equivalent and effective dose, used to express radiation risk to people.
Gray
The SI unit of absorbed dose, equal to one joule of energy deposited per kilogram.
Roentgen
A unit of exposure that measures how much X or gamma radiation ionises air.
Dose limit
The maximum dose a worker or member of the public may legally receive from regulated sources in a set period.