The Model AFS-442 is a general purpose proving switch designed for package burner, furnace, fuel-burning equipment, HVAC and other Energy Management applications. It can be used to sense positive, negative, or differential air pressure.

The plated housing contains a diaphragm, a calibration spring and a snap-acting SPDT switch.The sample connections located on each side of the diaphragm accept 1⁄8″ pipe.

An enclosure cover guards against accidental contact with the live switch terminal screws and the set point adjusting screw. The enclosure cover accepts a 1⁄2″ conduit connection.