Krohne Messtechnik Gmbh

Krohne Messtechnik Gmbh Co. Kg

Krohne Ag

Krohne Mebtechnik Gmbh & Co. Kg

Wilhelm Florin

Helmut Brockhaus

Markus Dabrowski

Boudewijn Jozef Poortmann

Detlef Ludwig

Jürgen Lehmkuhl

Juergen Lehmkuhl

Wolfgang Stelz

Christiaan Johan Hoogendijk

Arnould Leendert Van Willigen

Dr Helmut Brockhaus

A magnetic-inductive flowmeter and method in which a control circuit and/or evaluation circuit is designed/operated in such a manner that a measuring voltage tapped or tappable by measuring electrodes for flow measurement are evaluated only during a flow measuring time that is less than half the duration of the period of generation of the magnetic field and that the control circuit is designed/operated in such a manner that the measuring electrodes are impinged with conductivity measuring signals only during a conductivity measuring time that lies outside the flow measuring time.

Magnetic-inductive flowmeter and method for operating a magnetic-inductive flowmeter

A magnetic-inductive flowmeter for measuring the flow of a conductive medium having a measuring tube, a magnetic field generator, a magnetic circuit device for guiding the measuring magnetic field, electrodes for detecting a flow-dependent electrical measuring voltage when the conductive medium flows through the measuring tube, and an electronic control and evaluation unit, and a method for operating the magnetic-inductive flowmeter. To make the magnetic-inductive flowmeter which smaller and cheaper, a sensor for detecting a physical disturbance variable acting on the magnetic circuit device is arranged on the magnetic circuit device, wherein the measuring magnetic field is influenced by the physical disturbance variable and wherein the control and evaluation unit is designed such that it detects and signals an exceeding or falling below of a pre-definable limit value of the physical disturbance variable and/or performs a correction of the effect of the physical disturbance variable on the flow measurement.

A method for operating a magnetic-inductive flowmeter that has at least one measuring unit for measuring the flow of a medium through a pipeline, a housing and at least one control and evaluation unit, wherein the measuring unit has at least one coil for generating a magnetic field, and wherein at least one capacitance formed in conjunction with the coil forms a resonant circuit and wherein the resonant circuit has at least one measured variable characterizing it. A particularly reliable operation of the flowmeter is achieved in that the resonant circuit is excited with an excitation frequency, that the measured variable characterizing the resonant circuit is determined, that a comparison value of the measured variable characterizing the resonant circuit for the leak-free case is stored in the control and evaluation unit and that the measured variable characterizing the resonant circuit is compared to the comparison value.

Method for operating a magnetic-inductive flowmeter and magnetic-inductive flowmeter

An electrical function group with a control device and a first voltage regulator, the control device having a supply voltage input, the first voltage regulator having a first supply voltage input and a first supply voltage output and being designed for connection to a supply voltage source via the first supply voltage input and to supply the control device via the first supply voltage output, the first supply voltage output and the supply voltage input being connected together. A second voltage regulator is also provided having a second supply voltage input and a second supply voltage output, the second voltage regulator being designed to be connected to the supply voltage source via the second supply voltage input and to supply the first voltage regulator and the control device via the second supply voltage output, the second supply voltage output and the first supply voltage input being connected to one another.

Electrical function group

Described and shown is a method for operating a flowmeter () having a measuring tube (), wherein the flow (d) of a medium () through the measuring tube () is measured. A continuous dwell time of the measured flow (d) greater than or equal to a flow threshold (d) is assigned to a flow interval (&#x394;t, &#x394;t) and a flow volume (V, V) is determined from the measured flow (d) in the flow interval (&#x394;t, &#x394;t). In each case, a continuous dwell time of the measured flow (d) less than the flow threshold (d) is assigned to a zero flow interval (&#x394;t). In each case, a deviation volume of the flow volume (V, V) in one of the flow intervals (&#x394;t, &#x394;t) from a reference flow volume is determined and the deviation volume is compared to a threshold deviation volume. If the deviation volume in one of the flow intervals (&#x394;t, &#x394;t) is less than the threshold deviation volume, a zero flow through the measuring tube () is determined and compensated using the measured flow (d) in the zero flow interval (&#x394;t) directly preceding the flow interval (&#x394;t, &#x394;t).

Method for operating a flowmeter and respective flowmeter

A method for setting a constant magnetic field strength of a magnetic field within a commutation interval using a magnetic-inductive flowmeter having a current controller with which time for setting the constant magnetic field strength of a magnetic field is relatively shorter. Additionally, a first interval having a starting point in time and an ending point in time and a second interval having a starting point in time and an ending point in time are arranged within a commutation interval. A first setpoint current curve for the first interval differs by a difference current curve to effectuate a higher rate of change. A second setpoint current curve is assigned to the constant setpoint current. The current controller is fed the first and second setpoint current curves.

Method for setting a constant magnetic field strength of a magnetic field and a flowmeter

A magnetic field generator () of a magnetic-inductive flowmeter for generating an alternating magnetic field running at least also perpendicular to the longitudinal axis of a measuring tube, wherein at least one field coil (), a current regulator (), a switching bridge () and a microcontroller () all form part of the magnetic field generator (). Two different coil voltages are provided for the coil power supply, namely an initial voltage and a lower operating voltage, and a voltage selector () is provided for switching from the initial voltage to the operating voltage&#x2014;and vice versa.

Magnetic-inductive flow meter and method for operating a magnetic-inductive flow meter

A magnetic-inductive flowmeter has a plurality of functional units and a housing which is common to all of the functional units. Each functional unit has a measuring tube for an electrically conductive medium to flow through, a magnetic field-generating device having at least one field coil for generating a magnetic field which runs at least also perpendicular to the longitudinal axis of the measuring tube, and two measuring electrodes. A virtual connecting line between the measuring electrodes runs at least substantially perpendicular to the direction of the magnetic field which passes through the measuring tube. A common medium-inflow connection is created in the housing for the measuring tubes of all of the functional units, a common power supply is created for the magnetic field-generating device of all of the functional units, and a common evaluation unit is created for the measuring electrodes of all of the functional units.

Magnetic-inductive flowmeter device having a plurality of flowmeter units, power supply and evaluating units provided in a common housing

A magnetic-inductive flow meter with at least one measuring tube for through flow of an electrically conductive medium, with a magnetic field generating apparatus for generating an alternating magnetic field which runs at least also perpendicular to the longitudinal axis of the measuring tube, with at least two measuring electrodes which especially contact the medium and with an evaluation circuit, the magnetic field generating apparatus having at least one field coil and one coil power supply. Because the measuring electrode circuit, therefore the electrical circuit to which the measuring electrodes belong is monitored by a crosstalk voltage indicator of the evaluation circuit which is active in an operating state when an electrically conductive medium is not flowing through the measuring tube, whether the measuring electrode circuit is serviceable can be derived from the crosstalk voltage.

Magnetic-inductive flowmeter having-an evaluation circuit with a crosstalk voltage indicator to indicate a 'no-flow' state

A magneto-inductive flowmeter having at least one measuring tube for the flow of an electrically conducting medium, having at least one magnetic field generator for generating a preferably alternating magnetic field running at least also perpendicular to the longitudinal axis of the measuring tube, having at least two measuring electrodes&#x2014;in particular in contact with the medium&#x2014;and having a functional unit containing at least one evaluation unit and a method of operating same. The magneto-inductive flowmeter is user-friendly in a very particular manner, namely in that the functional unit has a request initiator that can be activated&#x2014;by the user or the flowmeter itself&#x2014;, a contacting receiver and an information sender and that by the request initiator, a third party can be prompted&#x2014;by the user or the flowmeter itself&#x2014;into contact&#x2014;with the user or with the flowmeter itself.

Magneto-inductive flowmeter having a functional unit with a request initiator activated by a user or the flowmeter

A method for operation of several adjacent magnetic-inductive flow meters, each of which has a measurement tube through which an electrically conductive medium flows, a magnetic field generating apparatus for permeating the medium with a magnetic field having a component perpendicular to the longitudinal axis of the measurement tube, and a measurement apparatus for measuring the voltage induced into the medium and for determining the flow rate from the induced voltage. Each flow meter has a control apparatus. In order to prevent variations of mutual influences on the flow rate measurements by the magnetic fields of adjacent flow meters, measured flow rate values from individual measurement processes and synchronous measurement processes are used to determine the mutual influences on the flow rate measurements, and influences that are free of variations are compensated by the magnetic fields of the adjacent flow meters being synchronized.

Method for operation of several adjacent magnetic-inductive flow meters

A non-intrinsically safely supplied measurement device () with a connecting device () having an 'increased safety' type of protection for connecting the measurement device () to a feed connection () in order to supply the measurement device () with electricity, an electronic device () which contains electronic components of the measurement device (), a display device (), a sensor () made with 'increased safety' or &#x201c;intrinsic safety&#x201d; type of protection, and an output circuit () that is without at least the &#x201c;intrinsic safety&#x201d; type of protection. The electronic device () has an &#x201c;encapsulation&#x201d; type of protection, the display device () has an &#x201c;intrinsic safety&#x201d; type of protection and the display device (), the sensor () and the output circuit () are connected to the electronic device () via connections having an &#x201c;increased safety&#x201d; type of protection.

Non-intrinsically safely supplied measurement device

A magnetoinductive flowmeter and a method for operating same utilizing a measuring tube through which flows an electrically conductive medium, as well as two measuring electrodes and a magnet with two field coils positioned parallel to each other on mutually opposite sides of the measuring tube. The measuring electrodes are so positioned that their connecting line extends along an essentially perpendicular vector relative to the direction of flow and to the magnetic field as well as through the cross-sectional center of the measuring tube. For normal flow-measuring operation, the two field coils are so energized that an essentially homogeneous magnetic field is generated, permeating the medium flowing through the measuring tube, while for determining the flow rate the voltage present between the two measuring electrodes is collected at one or both measuring electrodes and measured against a reference potential. The normal flow-measuring operation is intermittently interrupted and the two field coils are energized in a manner as to generate an inhomogeneous magnetic field that permeates the medium flowing through the measuring tube, and the voltage present between the two measuring electrodes is collected. This permits a diagnosis of the flowmeter.

Magnetoinductive flowmeter and method for operating a magnetoinductive flowmeter

The magnetoinductive flowmeter measures the flow volume of a medium traveling through a measuring tube, with a magnet that serves to generate a magnetic field permeating the measuring tube that has a magnetic-field component that extends perpendicular to the direction of flow. The flowmeter also includes a first measuring electrode and a second measuring electrode for collecting a voltage induced in the medium, a reference electrode, as well as a preamplifier to which the potentials collected by the two measuring electrodes are fed. A control circuit element is provided for controlling the common-mode input voltage of the preamplifier and/or the potential span of the dynamic range of the preamplifier in such fashion that the said common-mode input voltage of the preamplifier corresponds to approximately half the maximum output voltage of the preamplifier. This concept also permits the use of preamplifiers that operate with a low supply voltage such as 0/5 V. A measuring method is also disclosed.

Magnetoinductive flowmeter and measuring method for a magnetoinductive flowmeter

A method for operating a magnetoinductive flowmeter of the type including a measuring tube through which flows an electrically conductive medium, at least two electrodes that are in direct conductive contact with the medium, and at least one magnetic field coil that serves to generate a magnetic field which permeates at least part of the medium and in which a predefined current is impressed between two electrodes that are in wet contact with the flowing medium, the voltage present between the two electrodes or between one of the two electrodes and another electrode that is in wet contact with the flowing medium is measured, and a resistance value is derived from the ratio of the impressed current to the measured voltage. This permits the determination and read-out of the conductivity of the medium flowing through the measuring tube, which constitutes an added benefit for the user of the magnetoinductive flowmeter.

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Duisburg, Germany

Wilhelm Florin