Evaluation of two commercially available portal monitors for emergency response

The Human Monitoring Laboratory has compared two types (the P3 and the MiniSentry) of portal monitors that can be field deployed in response to an emergency. They can be used to screen persons for internal or external radioactive contamination by fission activation products (neither unit is capable of detecting alpha or beta radiation, and the amount of material required to alarm the monitors is unacceptably high for low energy x rays or gamma rays) following an incident involving the release of radioactive material (accidental or intentional). It was found that the P3 benefits from simplicity but requires slightly more activity to alarm than the MiniSentry, although for emergency response, the amount of activity that can be detected is far below a level where significant health effects will occur. The MiniSentry was found to have more capability than the P3, but these benefits also bring their own disadvantages. It was also found that the MiniSentry would be difficult to deploy in an outdoor setting whereas the P3 is well designed for a field setting. Despite the differences found, the HML has concluded that both have a distinct place in emergency monitoring. In the future, the HML plans to have both instruments ready for field deployment.