Krohne Messtechnik Gmbh

Krohne Messtechnik Gmbh Co. Kg

Markus Dabrowski

Helmut Brockhaus

Wilhelm Florin

Christoph Spiegel

Christian Hansen

Rene Keimling

Michael Gerding

Jan Förster

Thomas Fritsch

Ralf Kaisler

Ulrike Schwenger

A method for operating a magnetic field generator for a magnetic-inductive flowmeter is disclosed. The method involves setting, at a first reversal time, a target current value as target current and a first target voltage value as target voltage. The first target voltage value is greater than a second target voltage value, and the second target voltage value as target voltage effects the control voltage value of a current regulator voltage in a steady state of the magnetic field generator. The method further involves determining a first switching time. The current between a first reversing time and the first switching time reaches the target current value. A current regulator voltage at the first switching time is greater than a minimum voltage value and less than a control voltage value. At the first switching time, the second target voltage value is then set as the target voltage.

Magnetic field generator for a magnetic-inductive flowmeter, method of operating the same, magnetic-inductive flowmeter and method of operating the same

A magnetic-inductive flowmeter includes a tube, electrodes in contact with a medium in the tube, a magnetic field generator, an impedance signal generator, and a control device. A first signal path interconnects the impedance signal generator and a first electrode, and a second signal path interconnects the impedance signal generator and a second electrode. A first switch and first and third capacitors are connected such that, in a first state, only the first capacitor and, in a second state, only the third capacitor is in the first signal path. A second switch and second and fourth capacitors are connected such that, in a first state, only the second capacitor and, in a second state, only the fourth capacitor is in the second signal path. The control device sets the switches to the first state during a positive magnetic phase and to the second state during a negative magnetic phase.

Magnetic-inductive flowmeter and method of operating the same

A method for operating a magnetic-inductive flowmeter includes: detecting the noisy raw measurement signal having a first signal path by a signal sensor with high impedance by the pair of electrodes; passing the detected, noisy raw measurement signal on to a first signal processing device; processing the detected, noisy raw measurement signal by the signal processing device at least into a noise-removed flow measurement signal; outputting the noise-removed flow measurement signal via a working signal interface; detecting the detected, noisy raw measurement signal of the first signal path with a second signal path; and transmitting the detected, noisy raw measurement signal at least indirectly to the first signal processing device and/or a second signal processing device. The first signal processing device and/or the second signal processing device also carry out a frequency analysis of the detected, noisy raw measurement signal. A corresponding magnetic-inductive flowmeter is also disclosed.

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

A magnetic-inductive flowmeter includes a measuring tube for carrying an electrically conductive medium, a magnetic field generator for generating a magnetic field passing through the medium, two electrodes for tapping a measuring voltage induced in the medium, a ground element electrically connected to the medium, and an evaluation unit. The electrodes are connected to the evaluation unit via electrode lines. The ground element is connected to the evaluation unit via a first ground line for potential equalization between the medium and a reference potential of the evaluation unit. The ground element is connected to the evaluation unit at least indirectly via a second ground line. The first and second ground lines are part of a monitoring circuit for monitoring the connection between the ground element and the evaluation unit. The evaluation unit is designed such that it monitors the connection between the ground element and the evaluation unit.

Magnetic-inductive flowmeter and method for the monitoring of the function of a magnetic-inductive flowmeter

A method for determining conductivity of a medium includes: generating a signal with first and second frequencies; feeding the signal to first and second electrodes; determining a first voltage between the first and second electrodes, a first current through the medium for the first frequency, and a first impedance from the first voltage and first current; determining a second voltage between the first and second electrodes, a second current through the medium for the second frequency, and a second impedance from the second voltage and second current; determining and comparing phases of the first and second impedances; determining a medium resistance with a first formula when the first impedance phase is smaller than the second impedance phase; determining a medium resistance with a second formula when the first impedance phase is equal to or greater than the second impedance phase; and determining conductivity of the medium using the medium resistance.

Method for determining a conductivity, operating method of a magnetic-inductive flowmeter and magnetic-inductive flowmeter

A magnetic-inductive flowmeter having a measuring tube for guiding a conductive medium, having a magnetic field generator for generating a magnetic field passing through the measuring tube at least partially perpendicular to the medium flow direction, electrodes for tapping a measuring voltage induced in the medium and a conductivity measuring device for determining the conductivity of the medium. The conductivity measuring device has a measuring circuit with the electrodes, a voltage source and a measuring unit. In operation, the voltage source generates a voltage and the measuring unit measures the actual electrode voltage applied between the electrodes. The control unit sets the actual electrode voltage to a predetermined constant setpoint value and the evaluation unit determines the electrode current flowing between the electrodes and calculates the conductivity value of the medium or a variable related to the conductivity using the determined electrode current and the actual electrode voltage.

Magnetic-inductive flowmeter having a conductivity measuring device and method for operating a magnetic-inductive flowmeter having a conductivity measuring device

A method for operating a flowmeter having at least one diagnostic unit, a counter unit and a storage unit with at least one memory for carrying out a plurality of time-limited measuring operations during which the counter unit determines at least the overall volume of a fluid passing through the flowmeter during one measuring operation. The counter unit is operated for the duration of a time-limited measuring operation, and the diagnostic unit recognizes at least one erroneous or error-free state of the flowmeter. The method ensures a particularly high reliability of the measured values determined during an individual measuring operation by the diagnostic unit generating at least one status message based on the state that is transmitted to the storage unit and stored in the memory, and by several status messages being transmitted and cumulatively stored in the memory at least for the duration of the measuring operation.

Method for operating a flowmeter and flowmeter

A method for providing safe access of a mobile control unit () to a field device (), wherein, in particular, the field device is protected against unauthorized access via a mobile control unit is achieved in that a connection for transmitting data is established between the mobile control unit () and the field device (), that access data for access is exchanged, that a comparison is made between the access data and stored comparison data and a comparison result is generated, and that access of the mobile control unit () to the field device () is permitted based on the comparison result.

Method for safe access to a field device

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 communication arrangement, a gate device and method for data communication between a mobile operating unit and a field device provides a certain ease in handling. The method involves a user program being loaded onto or activated on the mobile operating unit. Furthermore, data from the mobile operating unit is transmitted to a data communication device and from the data communication device to a gate device and from the gate device to a transmitting device of the field device and/or is transmitted in the opposite direction.

Method and communication system for data communication

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 data-recording device for a measurement device () that contains measurement device electronics () having an internal data bus and a data interface (), wherein the data-recording device includes at least one storage element (), at least one processing unit () linked with the storage element () and a data interface () and wherein the device can be linked with the measuring device via its data interface and via the corresponding data interface of the measurement device and data can be exchanged between the measurement device and the data-recording device. The data-recording device is able to read-only access the internal data bus of the measurement device () without functional interference via its data interface ()&#x2014;bus observation, thus avoiding certain disadvantages of similar prior data-recording devices.

Growing community of inventors

Duisburg, Germany

Markus Dabrowski