{"chart":"radiation-dose-rate-chart","generatedFrom":"All Unit Conversions shared conversion library","tables":[{"title":"Microsieverts per hour to mrem/h, yearly dose and time to 1 mSv","headers":["Dose rate (µSv/h)","mrem/h (≈ mR/h for gamma)","mSv per year (continuous)","Hours to receive 1 mSv"],"rows":[["0.01","0.001","0.08766","100,000"],["0.05","0.005","0.4383","20,000"],["0.1","0.01","0.8766","10,000"],["0.15","0.015","1.315","6,670"],["0.2","0.02","1.753","5,000"],["0.3","0.03","2.63","3,330"],["0.5","0.05","4.383","2,000"],["1","0.1","8.766","1,000"],["2","0.2","17.53","500"],["3","0.3","26.3","333"],["5","0.5","43.83","200"],["10","1","87.66","100"],["20","2","175.3","50"],["50","5","438.3","20"],["100","10","876.6","10"],["250","25","2,192","4"],["500","50","4,383","2"],["1,000","100","8,766","1"],["10,000","1,000","87,660","0.1"]]},{"title":"mrem/h (or mR/h for gamma) to µSv/h","headers":["Dose rate (mrem/h)","µSv/h","mSv/h"],"rows":[["0.001","0.01","1 × 10⁻⁵"],["0.002","0.02","2 × 10⁻⁵"],["0.005","0.05","5 × 10⁻⁵"],["0.01","0.1","1 × 10⁻⁴"],["0.02","0.2","2 × 10⁻⁴"],["0.05","0.5","5 × 10⁻⁴"],["0.1","1","0.001"],["0.2","2","0.002"],["0.5","5","0.005"],["1","10","0.01"],["2","20","0.02"],["5","50","0.05"],["10","100","0.1"],["25","250","0.25"],["50","500","0.5"],["100","1,000","1"],["1,000","10,000","10"]]},{"title":"Dose units for rate readings","headers":["From","To","Multiply by"],"rows":[["Microsieverts (µSv)","Millirem (mrem)","0.1"],["Millirem (mrem)","Microsieverts (µSv)","10"],["Millisieverts (mSv)","Millirem (mrem)","100"],["Rem (rem)","Millisieverts (mSv)","10"]]},{"title":"Reference doses as average dose rates","headers":["Reference","Dose","Average rate"],"rows":[["Public dose limit, planned exposures (ICRP 103)","1 mSv per year","0.114 µSv/h, continuous"],["World average natural background (UNSCEAR 2008)","2.4 mSv per year","0.27 µSv/h averaged over a year"],["UK average, all sources (UKHSA)","2.6 mSv per year","0.30 µSv/h averaged over a year"],["US average, including medical (NCRP 160)","6.2 mSv per year","0.71 µSv/h averaged over a year"],["Occupational limit (ICRP 103)","20 mSv per year","10 µSv/h over 2,000 working hours"]]},{"title":"Reading a survey meter or Geiger counter","headers":["Point","What to know"],"rows":[["Counts per minute (CPM)","CPM is not a dose rate. The conversion depends on the tube and the isotope; use the factor in your meter's manual."],["µR/h and µSv/h","For gamma rays, 1 µR/h ≈ 0.01 µSv/h is a common approximation (1 R = 8.76 mGy air kerma)."],["Background readings","Averages above include radon breathed in, which a gamma meter does not detect, so typical meter readings are lower."],["Dose from a rate","Dose (µSv) = dose rate (µSv/h) × time (h)."],["Distance","From a small source, the dose rate falls with the square of distance: twice as far gives a quarter of the rate."]]}]}