Abstract: A system is provided that accurately measures the quantity of liquid that is transferred through a flow meter. The system is composed of a flow meter with an ultrasonic fluid (liquid) sensor mounted therein that operates to sense the presence or absence of liquid flowing through the flow meter so that air flow is not erronecously measured as liquid flow. When there is substantially no liquid flow through the meter, the ultrasonic fluid (liquid) sensor interrupts the transmission of an output signal from a signal-conditioning circuit to a totalizer that operates to process the signal and total the amount of liquid so that any non-liquid material passing through the meter is not included in the total amount of removed liquid by the totalizer. Also provided are methods of using the system to accurately measure the amount of liquid flowing through a flow meter, such as in a grease trap pumping operation.

Abstract: A flow meter is provided that can be used to measure the flow of fluids from a fluid source to a receiving system, and methods of using the flow meter to measure fluid flow. The flow meter is composed of a housing that contains a fluid flow sensing member in the form of a rotatable bladed rotor or turbine in one chamber and a sensor and a signal-conditioning circuit in a second separate chamber. The rotor rotates by fluid flow through the housing chamber. The rotor preferably contains a magnet that passes over a magnetically-operated sensor and triggers it to produce a signal that is processed by the conditioning circuit into a 4-20 mA output signal that indicates a range from no flow to full flow of the liquid through the flow meter.

Abstract: Disclosed is a flow indicator including a tubular body containing a rod and a magnetized orifice member moving along the rod. The rod has a central ridge of greatest cross-sectional area, tapers toward either end and has a rate of taper which increases toward the end. In the repose position, an orifice is in registry with the ridge. The flow indicator detects relatively small flow rates and yet accommodates substantially greater flow rates without "topping out." One embodiment includes a magnetic follower on the outside of the body for coacting with the moving orifice member to indicate bi-directional flow.

Abstract: The improved flow meter has a generally cylindrical first tube with a rod assembly received in the tube and centrally supported therein. The rod portion of the rod assembly is tapered at a generally uniform rate over at least a portion of its length. An orifice disk has an aperture which is positioned generally concentric with the rod. This aperture coacts with the rod for providing an indication of the rate of flow of a fluid through the meter and against the urging of a spring. When fluid flows through the meter, the disk moves towards the second end of the tube and the magnitude of the movement has a known relationship to the rate of flow. A second embodiment of the flow meter includes a magnetized sleeve and a follower, the latter confined for movement between the first inner tube and the second outer tube. The orifice disk, sleeve and follower move coincidently and the meter is thereby adapted for use with opaque fluids.