The unit of measurement “sievert” (Sv) is used to indicate the effect of ionising radiation on organisms. Various dose quantities are given in sieverts, e.g. the equivalent dose or the effective dose.

Since 1 Sv is already a very high value, only fractions are usually used - millisievert (mSv) and microsievert (µSv). The following applies: 1 Sv = 1,000 mSv = 1,000,000 µSv.