NUCLEAR RADIATION SAFETY GUIDE
- The number of ionizations recorded over a period of time indicates the amount of radiation present. This is often done in one minute time intervals, resulting in the "beats per minute" or CPM. The higher the CPM, the higher the radiation levels ...

5-50 CPM (0.03-0.33 µSv/h): Normal background. No action needed.
51-99 CPM (0.33-0.65 µSv/h): Medium level, check the reading regularly.
>100 CPM (>0.65 µSv/h): High level. Closely watch the reading, find out why.
>1000 CPM (>6.50 µSv/h): Very high. Leave the area ASAP, and find out why.
>2000 CPM (>13 µSv/h): Extremely high. Evacuate immediately, report to Government.