From the Manufacturer:
The CANBERRA Argos-AB family of Whole Body Surface Contamination Monitors provides the ultimate user-friendly operation, with thorough and reliable detection of external contamination on personnel working in nuclear environments.
The Argos-5AB features their most advanced gas flow detectors optimized for the best possible alpha and beta response (along with minimizing the gamma response). The detectors have been arranged in a configuration that minimizes dead space and provides optimal contour geometry and coverage for the occupant.
All Argos monitors use a sophisticated "fast following" background trending and release-limit algorithm to provide the best possible performance in a stable or varying radiation field.
Excellent detector protection, modularity of components, and extensive diagnostics result in direct reductions in maintenance, repair, and operations costs.