Endress + Hauser Flowtec Ag

Endress+hauser Conducta Gesellschaft Fur Mess- Und Regeltechnik Mbh+co. Kg

Frank Schmalzried

Wolfgang Drahm

Heinz Rufer

Stefan Heidenblut

Alfred Rieder

Thomas Sulzer

Nikolai Fink

Thomas Küng

A method for operating a magnetically-inductive flowmeter, wherein the magnetically-inductive flowmeter includes: a measuring tube for guiding a flowable medium; at least two measuring electrodes for detecting a flow velocity-dependent measuring voltage induced in the medium; and a magnetic field-generating device for generating a magnetic field passing through the measuring tube, wherein the magnetic field-generating device includes a coil system with at least one coil, includes determining a deviation σ of a reactance of the coil system or of a variable dependent upon the reactance of the coil system from a desired value. A magnetically inductive flowmeter is also disclosed.

Method of operating a magnetically-inductive flowmeter

The present disclosure relates to a method for operating a magnetoinductive flowmeter as well as to such a flowmeter, wherein a disturbance superimposed on a measurement signal is at least partially compensated for by negative feedback of the disturbance to the measurement signal.

Method of operating a magneto-inductive flowmeter having comprehensive disturbance effect compensation

A method and flow measuring device for ascertaining flow of a medium through a measuring tube based on at least a first measurement signal, which depends at least on the flow velocity of the medium in the measuring tube, wherein the first measurement signal is registered, wherein an additional, second measurement signal is registered, which depends on the flow cross sectional area of the medium in the measuring tube and is independent of the flow velocity of the medium in the measuring tube, and wherein flow is ascertained as a function of the first and second measurement signals.

Flow measuring device and method for ascertaining flow of a medium through a measuring tube based on medium velocity and cross section

A method for operating a magneto-inductive flow measuring system, wherein the magneto-inductive flow measuring system has a measuring tube, wherein measuring tube has a lumen for the conveying an at least slightly electrically conductive, measured substance, and wherein the magneto-inductive flow measuring system has a first and a second electrode electrically interacting with the measured substance. In a first diagnostic operation, an input voltage is applied between the first and second electrodes, wherein the input voltage produces an electrical current essentially within the lumen, and wherein the flow measuring system additionally has a third and a fourth electrode electrically interacting with the measured substance, wherein an output voltage falling between the third and fourth electrodes essentially due to the electrical current is determined, and wherein, by means of the output voltage, a state of the flow measuring system and/or a chemical and/or physical property of the measured substance is determined.

Magneto-inductive flow measuring system and method

A method for predictive maintenance for a magneto-inductive flow-measuring device and/or to a method for determining electrical conductivity of a medium flowing through a magneto-inductive flow-measuring device, wherein the magneto-inductive flow-measuring device includes a magnet system, which produces a magnetic field passing through the measuring tube essentially transversely to a measuring tube axis; at least two measuring electrodes coupled with the medium, having a defined rest potential and being arranged in a region of the measuring tube lying essentially perpendicularly to the magnetic field; and a control/evaluation unit, which delivers information concerning volume- or mass-flow of the medium on the basis of measurement voltage induced in the measuring electrodes. A first exciting signal with a first frequency (f) and at least a second exciting signal with a second frequency (f), or an exciting signal containing at least two frequencies (f, f) are/is applied to the measuring electrode in such a manner that the average value of the exciting signals or exciting signal coincides, at least approximately, with the average value of the electrode potential of the measuring electrode. On the basis of at least one impedance value measured between measuring electrode and reference potential, conductivity of the medium and/or change on the surface of the measuring electrode are/is detected.

Method for predictive maintenance and/or method for determining electrical conductivity in a magneto-inductive flow-measuring device

A medium to be measured is allowed to flow through a measuring tube of a flow meter and a magnetic field passing at least sectionally with a time-varying intensity through the medium in the measuring tube is produced in such a manner that a measurement voltage is induced at least at times, especially in a clocked manner, in the medium. The measurement voltage induced in the medium is tapped, at least at times, by means of an electrode pair formed by first and second measuring electrodes for producing an analog measurement signal corresponding with the measurement voltage, and a flow-type of the medium located in the measuring tube, as determined by an instantaneous flow profile and/or an instantaneous composition of the flowing medium, is ascertained with application of a digital signal representing the at least one measurement signal. Starting on the basis that the measurement signal has a wanted-portion corresponding essentially with an instantaneous flow velocity of the medium and a noise portion influenced at least partially by existent disturbances in the flowing medium, ascertained are: a noise spectrum of the measurement signal corresponding with the noise portion; and, with application at least of a part of the noise spectrum, a state value signaling, at least qualitatively, at least one flow-type present in the measuring tube.

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Freising, Germany

Frank Schmalzried