单位转换公式
UNITS OF RADIATION MEASUREMENTThe curie is the number of particles per second from 1 gram ofRadium = 3.7 ×10 E10 counts/second = 37 billion cps = 37billion Becquerel.1 Becquerel （Bq） = 1 ｃount per second = 1 event per second1 microcurie = 1 uCi = 37,000 Bq = 37,000 cps.1 microcurie = 2.22×10E6 disintegrations / minute = 2,220,000cpm.1 nanocurie = 1 billionth of a curie = 2,220 disintegrations /minute.1 picocurie = 2.2 disintegrations / min. Dosage units:Gray （Gy） = 1 Joule/kgSievert （Sv） = Gray x QF, where QF is a "quality factor" based onthe typeof particle. The Sievert is a measure of biological effect. QF for electrons, positrons, ａnd xrays = 1 QF = 3 to 10 forneutrons,protons dependent upon the energy transferred by these heavierparticles.QF = 20 for alpha particles ａnd fission fragments. Converting older units:1 rad = 1 centigray = 10 milligrays （ 1 rad = 1cGy = 10 mGy ）1 rem = 1 centisievert = 10 millisieverts （ 1 rem = 1cSv = 10 mSv ）1 mrad = 10 μGyNominal background radiation absorbed dose of 100 mrad/year =1 mGy/yr.Nominal background radiation dose biological equivalent of1mrem/year = 10usv/yr.Occupational whole body limit is 5 rem/yr = 50 μsv/yr.（ Recently proposed that levels be reduced to 2 rem/yr.）2.5 mrem/hr or 25 uSv/hr is maximum average working level inindustry.Exposure rate from Naturally Occurring Radioactive Material（NORM） ; anempirically derived conversion factor for Ra-226 decay series: 1.82 microR/hour = 1 picoCurie/gram.mR/h=10μSv/hmR=10μSv sievert的含义：在物理学上，我们已经知道三种射线α、β、γ （Χ射线属于低能β射线范围），它们不但有不同的物理特性，而且作用于人体的效果也不一样。为了让这三种射线在作用于人体时可以比较，一个数值被建立起来，这个数值基于射线作用于生物体的效果。 sievert西弗特 （符号Sv, 剂量当量单位, 1 Sv=100 rem）rem （roentgen equivalent man）雷姆, 人体伦琴当量未经许可，严禁转载！！！