Counts Per Minute CPM
Micro Sieverts per hour uSv/hr
Milli Sieverts Per year
Background Radiation Level Guide for
detections 1 meter above ground
12 0.10 0.88 Average background, pre Fukushima Japan .081 uSv/hr, Australia .17 uSv/hr,
25 0.21 1.83 0.23 uSv/hr world average, USA average 0.34 uSv/hr,
50 0.42 3.65 It is normal to occasionally get short duration peaks above normal background for any location.
60 0.5 4.34 Larger peaks of longer duration indicate detection of a hot spot, or a cloud of radiation is passing through!
100 0.83 7.3 Larger peaks of longer duration indicate detection of a hot spot, or a cloud of radiation is passing through!
150 1.25 10.95 Detections 1.0 uSv/hr and above you are getting into the very dangerous area of detection, shelter or leave immediately!
500 4.17 36.5 Even more dangerous, shelter or leave immediately! Know what your local average background radiation level was