Hampshire Controls' Air Flow Monitor (AFM) is a single probe instrument used for continuous monitoring of mass air flow levels within laboratory biocontainment cabinets, fume hoods, laminar flow hoods, and ventilation systems.    The AFM includes audible and visual alarms and a relay output to activate remote alarm and automatic notification systems.

A single 5/16" (8 mm) diameter, rapidly and repeatably responsive probe is inserted into the air stream.  A setpoint is established at the low end of the acceptable air flow range just above the desired low air flow alarm threshold.  If the air flow rate drops to the setpoint, a yellow WARNING indicator is initiated.  If the air flow remains below the setpoint for more than 7 seconds, then a red ALARM indicator begins flashing, an audible alarm is initiated, and the SPDT output relay is thrown.