The Foxboro Company

Other

Invensys Systems, Inc.

Peter B Lewis

Norman O Fonteneau

Richard W Kalinoski

Michael R Sheridan

Richard A Bertone

Vincent W Devore

Shiquan Wang

Norman Fonteneau

A magnetic flowmeter has a tube for supporting fluid flow including a circuit for indicating when the tube is empty to prevent an erroneous flow signal from being provided by the flowmeter, as well as a diagnostic circuit indicating when electrodes in the flowmeter are partially fouled. The circuits include an amplifier connected to two electrodes in the tube and a variable resistor. In a normally operating mode, the amplifier produces an oscillating signal when the tube is empty, and in a diagnostic mode, the amplifier produces an oscillating signal when the electrodes are partially fouled.

Magnetic flowmeter with diagnostics

A magnetic flowmeter has a tube for supporting fluid flow and a circuit for indicating when the tube is empty. The circuit includes an amplifier connected to two electrodes in the tube and a variable resistor. The amplifier produces an oscillating signal when the tube is empty. The circuit is calibrated for a particular fluid by finding a range of resistances for the variable resistor at which the circuit provides an accurate indication that the tube is empty, and storing information in the processor indicating a resistance in the range for the fluid.

Magnetic flowmeter with empty tube detection

A magnetic flowmeter has a tube for carrying fluid along a longitudinal axis. The tube has faces transverse to the longitudinal axis and disposed at opposite ends of the tube. A liner on the inner surface of the tube extends out from an end of the tube and into a recess on one face to anchor the liner in place.

Flow tube liner

Growing community of inventors

North Attleboro, MA, United States of America

Peter B Lewis