The AM3F is a continuous air monitoring system designed to measure the particulate, iodine and noble gas activity in a sample airstream. The AM3F uses three separate measuring channels arranged in series to perform the measurement. A common vacuum pumping system is used for transport of the sample gases through the system. Local RM1R display and control units are included for system operation, data concentration and communication.

The particulate channel uses a lead shielded fixed filter sampler providing collection of airborne on industry standard 47mm diameter filter paper. The filter paper deposition is designed to provide an even distribution and positions the active end of the detector in close proximity to the filter media for maximum sensitivity. The particulate channel will be equipped with a beta sensitive plastic scintillation detector (model SD201P) for detection of beta emitting particles. The detector interfaces with a locally mounted spectrum analyzer (model SDA3E) which provides the low voltage power to the detector, interfaces the detector/SCA with the ratemeter, and provides an automatic gain control function. The SDA3E unit communicates with the skid-mounted display and control unit (model RM1R) using Ethernet (TCP/IP), RS232 or RS485 communications for display of the measured activity and for alarm determination. The exhaust from the particulate channel is plumbed to the inlet of the iodine monitoring channel. The iodine monitoring channel is similar to the particulate channel and also uses a lead shielded sampler for collection of the iodine activity. In the iodine channel, a TEDA activated charcoal cartridge or silver zeolite cartridge replaces the particulate fixed filter media. A gamma sensitive scintillation detector (model SD220N) is placed within the lead shielded sampler with the sensitive end exposed to the collection cartridge. The SD220N detects the gamma events and provides the spectral information to an external SDA3E analyzer unit. The sample gases, with particulate and iodine activity removed, enter the noble gas sampler for measurement. The noble gas sampler (model GS54) is a lead shielded sampler enclosing a sensitive volume. A SD220N gamma scintillation detector or SD201P beta scintillation detector is located with the sensitive volume for measurement of noble gas activity.

The detector detects the nuclear pulses, provides biasing voltage, and transmits the count rate information to the locally mounted SDA3E analyzer. The noble gas sampler includes a vacuum transducer to automatically correct the measured activity to standard pressure.

The Vacuum pumping system uses a positive displacement carbon vane pump for transport of sample gases through the monitoring system. A mass flow meter and proportional control valve allows the sample flow rate to be either manual set to the desired flow or to match the sample flow rate to a stack or vent velocity for representative sampling. The flow rate is provided to the local RM1R electronics for determination of total release and for calculation of concentrations. Alarms are included for annunciation of a low flow condition.

The AM3F is provided fully wired and plumbed on an open frame skid for ease of maintenance. A power distribution enclosure is provided which distributes the required operating voltages to the system electrical components. In addition, the power distribution box provides an instrument ground function as well as providing circuit breaker protection for the system.