Reference: http://www.orcbs.msu.edu/radiation/radmanual(html)/appendixunits.html

Unit | Symbol | Brief Description | Use |
---|---|---|---|

Curie | Ci | 3.7 x 10^{10} disintegrations per second (2.22 x 10^{12} DPM) | Special unit of activity |

Becquerel | Bq | 1 disintegration per second | SI unit of activity |

Roentgen | R | 2.58 x 10^{-4} C/kg. (photons in air) | Special unit of exposure; applies only to gamma and x radiation |

Rad | rad | 0.01 J/kg (100 ergs/g) | Special dose unit; applies to any radiation |

Gray | Gy | 1 J/kg. | SI unit of dose (Equals 100 rads) |

Dose Equivalent | H | Dose x Q x any other modifying factors | Radiation protection |

Quality Factor | Q | Biological effectiveness related to type of radiation | Radiation protection |

Rem | rem | Rad dose x Q x any other modifying factors | Special unit of human dose equivalent |

Sievert | Sv | Gy x Q x any other modifying factors | SI unit of human dose equivalent (Equals 100 rem) |

Activity: | 1 Ci = 3.7 x 10^{10} Bq = 2.22 x 10^{12} DPM | ||

Exposure: | 1 R = 2.58 x 10^{-4} C/kg. | ||

The special unit for exposure is the Roentgen. There is no SI unit for exposure; it is simply expressed in C/kg. | |||

Dose: | 100 rads = 1 Gy | ||

Dose Equivalent: | 100 rems = 1 Sv | ||

KeV: | Kilo (1000) electron volts | ||

MeV: | Mega (1,000,000) electron volts | ||

1 MeV = 1000 keV | |||

1 KeV = .001 MeV | |||

1 Ci = 3.7 x 10^{10} Bq = 37 GBq | |||

27 uCi = 1 x 10^{6} Bq = 1 MBq | |||

1 rad = 0.01 Gy = 10 mGy | |||

1 rem = 0.01 Sv = 10 mSv |

File: radunits.html

Back to List of Documents