Always store control monitors away from any radiation sources.

What is a control monitor?

A control monitor is used to measure the radiation dose from the natural background radiation at your workplace. This dose is then subtracted from the measurements obtained by the personal monitors, leaving only the dose specifically related to occupational exposure. Our laboratory handles the background subtraction, which is why we exclude the control dose from the dose reports. The diagram below shows the relationship between a control monitor and a personal monitor.

A diagram that shows how a control radiation monitor accounts for dosage over time

How should control monitors be stored?

To ensure proper storage of the control monitor and personal monitors when not in use, it is important to keep them in a location that is not exposed to radioactive materials or near radiation-generating equipment. Since each workplace is different, there is no universally ideal storage location. However, here are some general guidelines and considerations to keep in mind:

  • Store the monitors in an area that is easily accessible to all individuals who are being monitored.
  • Choose a storage location that reflects the typical background radiation levels in your workplace. This means keeping the monitors away from any radioactive sources, but not storing them in a shielded container.
  • Store the monitors away from walkways or areas where radiation sources or nuclear medicine patients may pass through.
  • If your workplace consists of multiple buildings or floors, it may be advisable to have separate control monitors for each of these areas.

Below is an example of how control monitors and personal monitors can be stored when not in use.

A wooden wall containing shelves of radiation monitor cases

What is the difference between a control monitor and an area monitor?

A control monitor is used to measure the background radiation level that is then subtracted from the personal monitors to calculate their occupational dose. On the other hand, an area monitor provides continuous measurement of ambient radiation levels above the background in a particular area. Area monitoring is especially useful for tracking radiation level trends over time and for assessing the effectiveness of radiation shielding and other safety measures. It's important to note that control monitors and area monitors are used for different purposes and are not interchangeable.

Further information

Understanding Radiation
Ionising Radiation and Health

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