Personnel Portal Monitor - Model 52-1-1
CE Seal

The Model 52-1-1 Portal Monitor is used for Beta/Gamma personnel contamination monitoring and meets the FEMA standard for Emergency Response Portal Monitoring (FEMA-REP-21). It is designed to be disassembled for ease of transportation and storage, and can be set up in  five minutes or less without any tools.
The non-volatile parameters are preset at the factory to detect a 1.0 μCi137Cs source in a 10 μR/hr background field. The electronics are microprocessor-based for ease of setup and reliability.  Status LEDs indicate count-cycle status. Audible signals accompany the LEDs for additional indication. Detector counts, background, and all parameters may be viewed on the Liquid Crystal Display (LCD). All setup is accomplished by way of pushbuttons located below the LCD.
These portal monitors can be operated in a walk-through basis with a quick scan occurring while a person is positioned within the portal. In this mode, checking is performed every 200 milliseconds while the portal is occupied, 600 milliseconds before, and 600 milliseconds after the portal is occupied. The portal monitor can also monitor in a stop-and-count mode, allowing for a more sensitive scan. In stop-and-count mode, the fixed count time may be set from 1 to 20 seconds.
These instruments have automatic background update and dynamic alarm setting capabilities. On startup, the instrument will take a background count and calculate alarm levels for each detector. Self-diagnostic routines check the background count and warn if the background becomes either too high or too low. Alarms are calculated with a user-adjustable sigma parameter and the current background count. During setup, the user can also specify individual alarms only, sum alarm only, or both individual and sum alarm. The sum alarm groups upper detectors and lower detectors.

Model 52-1-1 is able to operate from 85–250 Vac 50/60Hz without a voltage selector switch. They may also be operated from three “D” cell batteries. Battery lifetime is approximately 24 hours.
The portal monitors of the Model 52 series, including Model 52, Model 52-1, Model 52-5, Model 52-6, and versions thereof, are supplied with a polypropylene weather sleeve to protect against wet weather conditions.