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Fluid flow meter utilizing pressure sensing

An improved fluid flow meter for measuring a liquid flow rate is disclosed. It comprises a container having an interior cavity, an inlet opening, a vent opening, a first passageway and a second passageway. The first passageway has an upper opening which is sealed by a pressure transducer and has a lower opening which opens into the interior cavity below the inlet and vent openings. A pressure signal produced in the first passageway by liquid in the cavity is converted into a flow rate by a processor which is connected to the pressure transducer. The second passageway has a lower opening in communication with the interior cavity above the lower opening of the first passageway and an upper opening below the upper opening of the first passageway which is connected to a downwardly depending drain tube to drain the level of liquid in the cavity down by siphon action. In one embodiment the vent opening and the second passageway are in communication with the upper portion of a second cavity which is provided below the first cavity and has a lower outlet opening.

Flow meter

A flow meter including a housing having inlet and outlet ports, at least two associated pistons provided respectively in respective cylinders in the housing, metering chambers defined respectively on one sides of respective pistons, passages formed in the housing for communicating the metering chambers with inlet and outlet ports, and a valve mechanism provided in the housing and associated with the movement of pistons for communicating either of the metering chambers with the inlet port and communicating the other of metering chambers with the outlet port. A check valve is provided in a passage between the inlet port and the valve mechanism for permitting liquid flow from the inlet port to the valve mechanism and preventing the liquid flow in the reverse direction.

Instrumental error compensation circuit for flow meter

An instrumental error compensation circuit for a flow meter is disclosed in which a flow rate calculated from an output signal of the flow meter is identified with respect to a plurality of predetermined sections of flow rates. Flow rate compensation coefficients are calculated by linear interpolation on the basis of actually measured data which are obtained in advance in accordance with instrumental errors of the flow meter. Actual flow rates of a fluid are measured with the instrumental errors of the flow meter compensated for by the calculated coefficients.

Air flow meter circuit with temperature compensation circuit

An air flow meter circuit with a temperature compensation circuit comprises an air flow rate detection circuit for generating an output signal in accordance with an air flow rate, an output circuit for amplifying the output signal of the air flow rate detection circuit to produce an output signal whose value is so adjusted as to be related to the value of the input signal in a predetermined relationship, and a constant voltage circuit for supplying a predetermined reference voltage to the air flow rate detection and output circuits. In order to compensate the output of the air flow meter circuit for its changes due to the influence of temperature coefficients of component parts of both the air flow rate detection and output circuits, the temperature coefficient of the output of the constant voltage circuit is so adjusted as to cancel out the temperature coefficients of the parts constituting the air flow meter circuit.

Retrievable downhole flow meter
Capacitative electromagnetic flow meter
Ultrasonic flow meter with reduced noise
Coriolis mass flow meter having a thick-walled measuring tube
Detector for an ultrasonic flow meter
Karman vortex flow meter
Coriolis mass flow meter employing non-metallic flow conduit structure
Fluidic volumetric fluid flow meter
Electromagnetic flow meter
Fluid flow meter utilizing pressure sensing
Air flow meter
Fluid flow meter
Liquid flow meter construction
Positive displacement flow meter method and apparatus
Magnetic-inductive flow meter with a measuring tube made of plastic

PAT. NO. Title
451 4589280 Fluid flow meter utilizing pressure sensing
452 4583400 Flow meter
453 4581946 Instrumental error compensation circuit for flow meter
454 4581929 Air flow meter circuit with temperature compensation circuit
455 4579008 Electromagnetic pulse pick-up arrangement in a flow meter
456 4574644 Ball bearing flow meter and pump
457 4569233 Flow meter indicating device
458 4562731 Air flow meter
459 4561312 Turbine for a multijet liquid flow meter
460 4561311 Bridge excitation for sensor used on a vortex shedding flow meter
461 4559814 Thermal air flow meter
462 4555951 Reflective acoustic fluid flow meter
463 4554926 Ultrasonic pulse Doppler blood flow meter with provision to create ultrasonic test waves which, when reflected from a stationary object, result in echoes similar to those produced by a moving object
464 4554687 Toilet mounted urine flow meter
465 4548084 Flow meter
466 4545257 Electromagnetic flow meter
467 4545244 Ultrasonic flow meter
468 4542651 Reciprocating piston flow meter with a fluid bypass
469 4542650 Thermal mass flow meter
470 4541437 Ultrasonic pulse Doppler blood flow meter
471 4528858 Flow meter
472 4526040 Oscillation compensating apparatus for vortex flow meter
473 4524627 Electromagnetic flow meter
474 4523478 Sonic flow meter having improved flow straighteners
475 4522073 Magnetic-inductive flow meter for high temperatures
476 4519257 Electronic flow meter for measuring flow of bulk solids pneumatically conveyed through a hose
477 4519246 Improved flow meter
478 4517838 Thermal mass flow meter
479 4513615 Thermal air flow meter
480 4507976 Flow meter with hall effect sensor and method
481 4498497 Flow meter bypass valve assembly
482 4495823 Bidirectional flow meter
483 4495802 Air flow meter assembly
484 4494405 Air-flow meter for internal combustion engine
485 4493215 Vibrator damping flow meter
486 4489616 Digital fluid flow meter
487 4489615 Fluid flow meter
488 4487076 Vortex flow meter
489 4484472 Concentric rod and tube sensor for thermal mass flow controller and flow meter
490 4481928 L-Jetronic fuel injected engine control device and method smoothing air flow meter overshoot
491 4478087 Karman's vortex street flow meter
492 4476728 Vortex flow meter
493 4467644 Flow meter
494 4466293 Volume flow meter for a flowing medium
495 4459858 Flow meter having an electromagnetic sensor probe
496 4458542 Electromagnetic flow meter with wide band preamplifier
497 4453937 Drainage device with flow meter
498 4453418 Flow-meter for fluids, with constant pressure loss
499 4452176 Milk flow meter
500 4451207 Turbine rotor for a flow meter

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