A control monitor is sent with each group of personal monitors to measure background radiation.
The occupational dose for a worker is calculated by subtracting the ‘background’ radiation of the control monitor from the worn workers monitor. This calculation is conducted by the PRMS.
Any reading from a personal monitor that is above that of the control is assumed to be due to occupational exposure.
You should store the control monitor at a location in your workplace that is not exposed to radiation from materials or apparatus used.
We cannot inform you exactly where to store the control monitor as we are unfamiliar with your workplace.