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Radiation units
Intermediate
Gray, sievert and becquerel.
Becquerel (activity), gray (absorbed dose, J/kg) and sievert (equivalent dose = dose × weighting factor). Natural background is about 2.4 mSv/year.
A chest X-ray ≈ 0.1 mSv.
Sv accounts for the type of radiation.
In more detail
Radiation units include the gray for absorbed dose, the sievert for equivalent dose, and the becquerel for activity. The sievert accounts for the biological effectiveness of different radiation types.
Real-world uses
- Radiation protection limits are set in sieverts.
- Medical dose planning uses grays and sieverts.
- Health physicists use the gray and sievert to record the dose of radiation absorbed and its biological effect.
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Frequently asked questions
What is the difference between gray and sievert?
The gray measures absorbed energy per kilogram, while the sievert weights it by biological effect.
What is a typical background dose?
About 2 to 3 millisieverts per year for most people.
What is the difference between gray and sievert?
The gray measures absorbed energy per kilogram, while the sievert weights that dose by the biological harm of the radiation.
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