Abstract: The present invention provides a device for generating an electrical output signal representative of the flow rate through a fluid flow meter of the type having a mechanical output member movable in an amount proportional to the fluid flow rate. The device comprises the U-shaped magnet having a north and south pole and a Hall effect transducer positioned between the poles of the magnet. The transducer produces an electrical signal representative of the distance between the transducer and one of the magnetic poles. The magnet in turn is connected to the mechanical output member from the flow meter so that the magnet moves in unison with the output member from the flow meter thus varying the transducer electrical output. The output from the transducer is electrically connected to a conventional electrical indicator to produce an indication of the fluid flow rate through the flow meter.

Abstract: A fluid flow meter comprising a housing having a fluid inlet, a fluid outlet and defining an internal fluid chamber. A fluid passageway is formed in the housing for connecting the inlet with one end of the chamber while the outlet is open to the other end of the fluid chamber. The ends of the chamber are closed at the outlet end by an end cap and the other inlet end by a cartridge assembly which includes an end cap. Central to the housing fluid passageway and to the inlet end cap is attached to a rod having a conical metering portion. Attached to the metering rod is a freely centering piston assembly sealed nearest the outlet end by a flexible seal. An axial bore is formed through the piston and an orifice plate is detachably secured to the piston at near midpoint in the axial bore. One side of the plate is open to the inlet end while the other side of the plate is open to the outlet end of the chamber.