Airborne Radiation Warning System.
Chap 148 in "Radiation Hazards in Mining: Control Measurement and Med Aspects" PP 980-983 :980-983
A 32-channel warning system for high working level, fan operation, and airlock-doors has been constructed. The working level monitors have a microcomputer for accumulating the pulses, converting to working level, and triggering an alarm at a variable set point and at one working level. The system can detect changes in air velocity which indicate surface fan failures or changes in the ventilation system. Using this alarm system, the ventilation engineer will be alerted prior to excessive levels of radon daughters being reached so corrective action can be taken.
Chap. 148 in "Radiation Hazards in Mining: Control, Measurement, and Med. Aspects", PP. 980-983