The Model 4906A is a low cost, industrial duty, alpha-only contamination monitoring system that uses six air proportional detectors for checking personnel. A large color LCD presents users with the system status and points out any potential contamination in an easy-to-use manner. Alarms are annunciated locally and can be augmented with optional relays for signaling remote devices or a light stack mounted on top. An Ethernet interface supports connection to a network for gathering all count cycles and remotely monitoring instrument status. All maintenance can be performed from the front of the instrument. Detector access for quick replacement or repair is facilitated by hinged top covers. The unit is equipped with rear-mounted wheels to facilitate transporting the instrument from one location to the next.