Abstract: A magnetoinductive flow measuring method for measuring the flow rate of a medium flowing through a measuring tube is described that incorporates two measuring electrodes positioned along a connecting line extending in an essentially perpendicular direction relative to the measuring-tube axis, whereby a magnetic field is generated that extends at least in an essentially perpendicular direction relative to the measuring-tube axis and to the connecting line of the measuring electrodes and whereby the flow rate of the medium moving through the measuring tube is determined by measuring the voltage, respectively collected at one or both measuring electrodes, in comparison with a reference voltage potential. According to the method, the flow measuring operation is initiated as soon as an increase in the flow rate is detected, thus permitting the precise measurement even of very rapid draw-off processes.

Abstract: A method is described for determining the uncertainty factor of a measuring process employing a measuring frequency, especially a magnetoinductive flow measuring procedure, whereby for each half-cycle of the measuring frequency at least one measured value is quantified by sampling a measuring signal. According to the method, the deviation of the measured values is determined at the measuring frequency but phase-shifted relative to the measuring frequency, and/or the deviation of the measured values is determined at a minimum of two frequencies differing from the measuring frequency and on the basis of the two deviations at the frequencies differing from the measuring frequency the deviation of the measured values at the measuring frequency is arrived at by interpolation or extrapolation. This permits easy access to the deviation at the measuring frequency, which is of significance as a diagnostic value.

Abstract: A magnetoinductive flowmeter incorporates a measuring tube, a magnet serving to generate a periodically alternating magnetic field that extends in a direction at least essentially perpendicular to the axis of the measuring tube, and two measuring electrodes positioned along a connecting line that extends in a direction at least essentially perpendicular to the axis of the measuring tube and to the vector of the magnetic field. An output device is provided by means of which a value for the constant-voltage component of the voltage collected at one or both of the measuring electrodes and differentiated from a reference potential is displayed to the user and/or is made available to the user for further processing. An equivalent flow-measuring process is also described.

Abstract: A mass flowmeter and a method for operating a mass flowmeter is based on the Coriolis principle and incorporates a Coriolis measuring tube, an oscillator associated with and stimulating said Coriolis measuring tube, and a transducer associated with the Coriolis measuring tube and which collects Coriolis forces and/or oscillations based on Coriolis forces. The electric power consumed in the mass flowmeter is controlled as a function of the available electric power. This permits the efficient use of the available electric power, thus permitting the operation of the mass flowmeter via a two wire interface that serves for both the input of electric power and the output of measuring data.

Abstract: An electric device features a two-wire interface which two-wire interface serves to feed electric power to the electric device and also to transmit a signal, with the maximum power drawn via the two-wire interface in normal operation being restricted to a predefined upper limit. The permissible maximum power consumption of the electric device is automatically and temporarily increased beyond the predefined upper limit when the electric device is switched into a special operational function mode. The length of time in which the electric device is in the special operational function mode can thus be reduced.

Abstract: A signal processing circuit for a differential voltage as the signal to be processed, especially for use in a magnetoinductive flowmeter, incorporating a preamplifier and, connected to the output of the preamplifier, an A/D converter. By employing as the preamplifier a differentially operating preamplifier, the circuit obtains in relatively simple as well as cost-effective fashion at the same time a high level of common-mode signal rejection and a substantial suppression of the low-frequency components in the differential signal occurring below the measuring frequency.

Abstract: A method is described for determining the uncertainty factor of a measuring process employing a measuring frequency, especially a magnetoinductive flow measuring procedure, whereby for each half-cycle of the measuring frequency at least one measured value is quantified by sampling a measuring signal. According to the method, the deviation of the measured values is determined at the measuring frequency but phase-shifted relative to the measuring frequency, and/or the deviation of the measured values is determined at a minimum of two frequencies differing from the measuring frequency and on the basis of the two deviations at the frequencies differing from the measuring frequency the deviation of the measured values at the measuring frequency is arrived at by interpolation or extrapolation. This permits easy access to the deviation at the measuring frequency, which is of significance as a diagnostic value.

Abstract: A magnetoinductive flow measuring method for measuring the flow rate of a medium flowing through a measuring tube is described that incorporates two measuring electrodes positioned along a connecting line extending in an essentially perpendicular direction relative to the measuring-tube axis, whereby a magnetic field is generated that extends at least in an essentially perpendicular direction relative to the measuring-tube axis and to the connecting line of the measuring electrodes and whereby the flow rate of the medium moving through the measuring tube is determined by measuring the voltage, respectively collected at one or both measuring electrodes, in comparison with a reference voltage potential. According to the method, the flow measuring operation is initiated as soon as an increase in the flow rate is detected, thus permitting the precise measurement even of very rapid draw-off processes.

Abstract: A mass flowmeter and a method for operating a mass flowmeter is based on the Coriolis principle and incorporates a Coriolis measuring tube, an oscillator associated with and stimulating said Coriolis measuring tube, and a transducer associated with the Coriolis measuring tube and which collects Coriolis forces and/or oscillations based on Coriolis forces. The electric power consumed in the mass flowmeter is controlled as a function of the available electric power. This permits the efficient use of the available electric power, thus permitting the operation of the mass flowmeter via a two wire interface that serves for both the input of electric power and the output of measuring data.

Abstract: A magnetically inductive flowmeter for flowing media, with a measuring tube, with a magnet for generating a magnetic field passing essentially perpendicular to the axis of the measuring tube and to the direction of the magnetic field, with at least two measuring electrodes arranged along a connecting line passing essentially perpendicular to the axis of the measuring tube and to the direction of the magnetic field, with a reference electrode and with a difference amplifier having a reference potential connection connected with the measuring electrodes via measuring electrode connections and serving for amplification of the measuring voltage present on the measuring electrodes.

Abstract: A measuring instrument, especially a flowmeter, whose measuring operation consists in the quantification of an output value as a function of an input value. According to the invention, the input value can be varied, the output value corresponding to a given input value can be measured, and a malfunction of the measuring operation of the measuring instrument can be detected on the basis of a deviation, beyond an established threshold value, of the output values measured at different input values, from the output value expected as a function of the relationship between the input value and the output value. The measuring instrument thus permits reliable and simple determination of a malfunction in the measuring operation by virtue of a self-test.

Abstract: An adapter circuit system for an electrically powered measuring device with two ports constituting a two-wire interface for connecting a dual-conductor cable capable both of feeding electric power to the measuring device and of transmitting a measuring signal from the measuring device for instance to an evaluation circuit. A second two-wire interface may be provided which permits the connection of a second cable capable of feeding additional electric power to the measuring device via two additional connecting ports. This permits universal operation of measuring devices equipped with the adapter circuit system due to the fact that in the event of increased power consumption by the measuring device, additional electric power can be supplied via the second two-wire interface.

Abstract: A magnetoinductive flowmeter incorporates a measuring tube, a magnet serving to generate a periodically alternating magnetic field that extends in a direction at least essentially perpendicular to the axis of the measuring tube, and two measuring electrodes positioned along a connecting line that extends in a direction at least essentially perpendicular to the axis of the measuring tube and to the vector of the magnetic field. An output device is provided by means of which a value for the constant-voltage component of the voltage collected at one or both of the measuring electrodes and differentiated from a reference potential is displayed to the user and/or is made available to the user for further processing. An equivalent flow-measuring process is also described.

Abstract: A magneto-inductive flow-measuring method for moving fluids, whereby the field coils generating the magnetic field are energized in gapped fashion and each measuring period includes a positive half-cycle of the magnetic field and a negative half-cycle of the magnetic field. The magneto-inductive flow-measuring method saves energy while at the same time permitting the simple and precise definition of the measuring signal by virtue of the fact that the measuring periods additionally include a section preceding the first half-cycle of the magnetic field and a section following the last half-cycle of the magnetic field, and that the additional signals measured therein are used to quantify an interference signal superposed over the measuring signal and to correct the measuring signal accordingly.

Abstract: A measuring instrument, especially a flowmeter, whose measuring operation consists in the quantification of an output value as a function of an input value. According to the invention, the input value can be varied, the output value corresponding to a given input value can be measured, and a malfunction of the measuring operation of the measuring instrument can be detected on the basis of a deviation, beyond an established threshold value, of the output values measured at different input values, from the output value expected as a function of the relationship between the input value and the output value. The measuring instrument thus permits reliable and simple determination of a malfunction in the measuring operation by virtue of a self-test.

Abstract: A device for determining the level of a conducting medium in a line, in particular for use in connection with a magnetically-inductive flowmeter, with at least one capacitor plate, with an insulation layer between the capacitor plate and the medium and with a control and evaluation circuit, the control and evaluation circuit acting upon the capacitor plate with an alternating voltage. The device is improved by having the control and evaluation circuit determine the capacitance between the capacitor plate and the medium as a measure for the level.