geigerteller

Stream videos at Ustream
geigerteller in chiba prefectuur (click this if you have trouble viewing the geigerteller on this blog), japan en 15km van tokyo
and output is in microsievert p/h (μSv/h).
1000 microsievert = 1 millisievert.
1 REM = 10 millisievert = 0.01 sievert and equals 1 RAD voor x-ray, gamma ray and beta particles.
A dose above 1000 REM is always fatal. 
More about radiationlevels on wikipedia .
Every time the tube detects a particle, a small back square flashes on the screen. Around this square, you will see some lines. When the unit starts to count, there are no lines. At the first 10 seconds, you will see two small lines and an extrapolation of that 10 seconds on the display. The unit makes sucesive extrapolations for the firsts 10, 20 and 30 seconds, making the first complete reading at the 40 seconds. At this time the value can be considered valid.
And here is another radiation level meter from tokyo, japan