Abstract: The invention relates to a magnetic-inductive measuring device for flowing substances with at least one subsystem respectively for carrying the substances, recording measuring signals through a signal pickup, generating a magnetic field through at least two exciting coils and a ferromagnetic core and bounding the measuring device on the ambient side of the housing. The measuring device is characterized in that at least one of the subsystems is entirely or partly formed by layers of fibre composite material and/or is embedded in layers of fibre composite material.

Abstract: The invention relates to a magnetic-inductive measuring device (1) for flowing substances (substance being measured), with a measuring tube (2) and a further subsystem respectively for recording measuring signals, comprising a signal pickup (electrode arrangement (20, 22) for signal tapping), for generating a magnetic field, comprising at least two exciting coils (30) and a ferromagnetic core (32) (magnetic system), and for bounding the device on the ambient side (housing), and is characterized in that at least one of the further subsystems is entirely or partly formed by a casting compound and/or embedded in a casting compound.

Abstract: An electromagnetic flow meter is disclosed which can be used to measure flow in low conductivity fluids, for example alcohol, turpentine, oil or other organic solvents. In one embodiment, the electromagnetic flow meter includes an elongate flow conduit having a direction of elongation corresponding to a direction of fluid flow, magnetic field generating means for generating a magnetic field across the flow conduit and potential sensing electrodes for sensing a potential generated by the magnetic field in a fluid flowing through the conduit. Both the field generating means and the potential sensing electrodes of the flow meter are elongate in the direction of flow.

Abstract: 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.

Abstract: A magnetoinductive flowmeter incorporates a magnet for generating a magnetic field that permeates the flowmeter's measuring tube with a magnetic field component perpendicular to the direction of flow, a first electrode and a second electrode which collect a voltage induced in the medium, and an amplifier to which the voltage collected by the electrodes is fed. A test voltage source and a comparator are provided, the test voltage source generating a test voltage, which is applied to the amplifier in a manner whereby the test voltage is superimposed over the voltage collected by the electrodes. The comparator is connected to the amplifier so that the output voltage of the amplifier can be fed to the comparator, and the comparator is designed in a manner whereby the output voltage of the amplifier can be compared with a reference value. This configuration permits easy calibration of the magnetoinductive flowmeter while during operation, any deviation from a calibrated condition can be detected reliably.

Abstract: The process measuring device includes a flow sensor having a measuring tube, a sensor arrangement for producing a measurement signal, and an evaluation and operating circuit. The method serves to compensate for the effects of interfering potentials which are caused especially by foreign particles or air bubbles in the liquid to be measured. For this purpose, an anomaly in the waveform of the measurement signal caused at least in part by an electrical, especially pulse-shaped, interfering potential is detected by determining within a stored first data set a data group which digitally represents the anomaly. To generate an interference-free data set, the data belonging to the data group are removed from the stored first data set.

Abstract: A magnetic flowmeter transmitter includes a differential amplifier that senses an additive combination of actual flowmeter electrode outputs and simulated electrode outputs. The differential amplifier provides an additive amplifier output. A simulator provides the simulated electrode outputs. The simulator senses the additive amplifier output and provides an error indication when the additive amplifier output is outside a normal range.

Abstract: The invention relates to a method and to a device for system- and/or process-monitoring in connection with a measurement apparatus that determines/monitors at least one process parameter of a medium. The method and device enable statements to be made regarding the present and future functionality of a measurement apparatus, or individual components of the measurement apparatus. The temperature values (T) of the medium are ascertained directly or indirectly and a trend analysis regarding the thermal loading of the measurement apparatus or the thermal loading of individual components of the measurement apparatus is carried out on the basis of the ascertained temperature values (T) of the medium or on the basis of the derivatives of the ascertained temperature values of the medium.

Abstract: A sensor assembly for a magnetic flowmeter is provided that is cost-effective to manufacture, while incorporating an effective seal against leakage and enabling precise positioning of electrodes. The sensor assembly includes an electrode assembly and a plastic housing molded about the electrode assembly. The electrode assembly includes an electrode and a plastic base disposed about the lower end of electrode. The housing includes a wall in direct contact with the plastic base such that the tip of the electrode projects from the wall, facilitating a secure seal about the electrode. The sensor assembly further includes a magnetic assembly configured to provide a magnetic field extending beyond the wall of the housing.

Abstract: A magnetoinductive flowmeter encompasses a ceramic measuring tube as a conduit for a medium whose flow rate is to be measured, and a measuring electrode featuring a cermet body. The measuring tube is mounted in the wall of the measuring tube with its side that faces the medium conductively or capacitively connecting to the medium while its side facing away from the medium connects to a measuring line. The cross-sectional surface area of the cermet body is larger at its end facing the medium than at its other end facing away from the medium. The result is a measuring electrode that fully meets the respective requirements at either end notwithstanding minimized material consumption in making the electrode. A method for producing a measuring tube for the flowmeter is also disclosed.

Abstract: A method for measuring a flow rate of a medium through a measuring tube which is penetrated by a constant magnetic field orthogonal to a flow direction and in which an electrical voltage building up in the medium is sensed by electrodes, insulted with respect to the medium and located on an outer wall of the measuring tube in a plane orthogonal to the flow direction of the medium, in which the capacitance of at least one capacitive unit is formed by the electrodes, and a measuring tube interior area and a charge change brought about by a change to the at least one capacitive is determined, and from this a voltage is established which is determinative of the flow rate of the medium through the measuring tube.

Abstract: Apparatus for detecting a parameter associated with the torque transmitted by a friction clutch, where the friction clutch has a clutch disk which is or can be connected for rotation in common to a power takeoff shaft. The apparatus includes a receiver area, which does not rotate with the clutch disk in the torque-transmitting state, and a code provided on the clutch disk. The code can be scanned by the receiver area and thus generates a sensor signal associated with transmitted torque.

Abstract: The flow sensor serves to measure an electrically conductive fluid flowing in a pipe. It comprises a flow tube designed to be inserted into the pipe for conducting the fluid, the flow tube being electrically nonconductive at least on a fluid-contacting inner side, an electrode arrangement consisting of at least two measuring electrodes disposed on the flow tube for picking up a voltage induced in the fluid, and a magnetic field system likewise disposed on the flow tube. The magnetic field system comprises at least two saddle-shaped field coils for producing a magnetic field cutting the fluid during operation of the flow sensor, a respective ferromagnetic pole piece for each of the two field coils, as well as at least one ferromagnetic return path extending around the flow tube upstream of the two field coils and at least one ferromagnetic return path extending around the flow tube downstream of the two field coils for directing the magnetic field around the flow tube.

Abstract: An electromagnetic flowmeter works with insulating liquids, and includes circuitry for handle drifting zero-point offset and triboelectric noise occurring in turbulently flowing dielectrics. Two signal processing schemes are presented—using high frequency induction and low frequency induction, but instead of measuring total voltage, the processor senses total voltage differentials, smooths the differentials, then integrates (sums) them such that the three components of total voltage are articulated—and, importantly, the flow voltage component itself is measured.

Abstract: A method of obtaining a measure of flow from an electromagnetic flow meter is disclosed. A shaped excitation waveform is applied to the flow meter and an output is received from the meter. The sampled output data from the meter is then resolved into a non-flow waveform component and a flow waveform component to derive a measure of flow. Resolving the data into expected waveform components rather than correlating each frequency component of the sampled output data with a sine wave may allow readings to be obtained without processing each frequency component separately. Also, the method may allow more accurate removal of the non-flow component from the output signal, and may decrease the time delay before the initial reading and allow the use of a greater reading repetition rate.

Abstract: In a borehole logging tool, the flow of conductive fluid into or out of a wellbore at the wellbore wall is detected and measured with a sensor loop proximate the borehole inner wall. The sensor loop includes a series of contiguous sensors that act as electromagnetic flowmeters and provide fluid measurements covering the entire circumference of the sensor loop. The sensor loop includes an elastic element that forces the sensor loop outward to maintain pressure along the sensor loop circumference against the interior borehole wall. The sensor loop is designed to lie at a non-perpendicular angle to the wellbore axis, and mechanical arms press the top and bottom of the loop against the borehole inner wall.

Abstract: There is described herein a method of obtaining a measure of flow from an electromagnetic flow meter having at least one field generating coil and potential sensing electrodes. A composite excitation waveform is applied to the field-generating coil. The composite excitation waveform comprises at least two frequency components and a plurality of frequency components are simultaneously present for at least a portion of the waveform. The potential sensed by the potential sensing electrodes is sampled to produce a sampled output and the sampled output is correlated with a composite waveform based on the composite excitation waveform. The result of the correlating is used to derive a measure of flow.

Abstract: The invention relates to a method and to a device for system and process supervision in a magneto-inductive sensor. A medium flows through a measuring tube substantially in the direction of the axis of the measuring tube. A magnetic field extends through the measuring tube in a direction substantially perpendicular to the axis of the measuring tube. A measuring voltage is induced in at least one measuring electrode that is disposed substantially perpendicular to the axis of the measuring tube. The measuring voltage or the measurement data provide information on the volume flow of the measuring medium in the measuring tube. In addition to the determination of the volume flow, the detection of the modification of a system and/or process parameter is also desired. For this purpose, the measurement data are acquired digitized and stored as actual measurement data over a predetermined period and the actual measurement data are compared with predetermined desired measurement data.

Abstract: A passive flowmeter having an inlet, sensing passage and outlet in fluid communication with one another, the sensing passage having a noncircular cross-section having a minor axis generally aligned with a permanent magnetic field and a major axis generally aligned with at least a pair of generally opposed electrodes for detecting a flow-dependent voltage induced by the passage of conductive liquid through the magnetic field. By using both permanent magnets and a noncircular cross-section sensing passage together in the same device, much greater latitude in magnet selection may be obtained. This may facilitate for example the use of lower cost permanent magnets and the construction of a lower cost device for disposable flowmeter applications.

Abstract: The invention is a detection system and in one embodiment uses inexpensive, miniaturized sensors for detecting electric field (E-field) disturbances. Such sensors are easily and covertly deployable and have low power consumption. The devices may incorporate visual or audio alerts and can include communications hardware for transmitting data for further processing of the electrostatic events.

Abstract: A resonator device for testing a material quantity in the tobacco-processing industry for existence of at least one foreign substance and/or for detecting at least one of weight, density and humidity level of the material includes a resonator housing having a through opening for the material to pass through and a testing region located inside the resonator housing to which the material can be moved at least in part. The device has at least one element that increases energy density of electromagnetic waves for increasing the energy density in at least a portion of the testing region.

Abstract: When a plane (PLN) which includes electrodes (2a, 2b) and is perpendicular to the direction of an axis (PAX) of a measuring pipe (1) is defined as a boundary in the measuring pipe (1), an exciting coil (3) applies asymmetrical magnetic fields to a fluid to be measured, which flows through the measuring pipe (1), on both sides of the plane (PLN) serving as the boundary in the measuring pipe (1). A signal conversion unit (5) obtains the phase difference between an exciting current supplied to the exciting coil (3) and an interelectrode electromotive force detected by the electrodes (2a, 2b). A flow rate output unit (6) calculates the flow rate of the fluid on the basis of the phase difference obtained by the signal conversion unit (5).

Abstract: A flowmeter for metering the volume of flow of a fluid through a filter, to enable the level of filter usage to be indicated. A preset level of metered fluid flow volume indicates a corresponding level of filter usage. The flowmeter is able to self-generate current responsive to the flow of the fluid therethrough.

Abstract: A magnetoinductive flowmeter that serves to measure the flow rate of a moving medium incorporates a measuring conduit, a sampling-electrode channel extending through the wall of the measuring conduit, and a sampling electrode, which sampling electrode is positioned in the sampling-electrode channel in such fashion that its sampling-electrode head is recessed from the inner wall of the measuring conduit. A section of the sampling-electrode channel located in front of the sampling-electrode head and extending up to the interior of the measuring conduit is left as a free space. This results in an improved signal-to-noise ratio of a voltage signal collected at the sampling electrode.

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: When a plane (PLN) which includes electrodes (2a, 2b) and is perpendicular to the direction of an axis (PAX) of a measuring pipe (1) is defined as a boundary in the measuring pipe (1), an exciting coil (3) applies asymmetrical magnetic fields to a fluid to be measured, which flows through the measuring pipe (1), on both sides of the plane (PLN) serving as the boundary in the measuring pipe (1). A signal conversion unit (5) obtains the phase difference between an exciting current supplied to the exciting coil (3) and an interelectrode electromotive force detected by the electrodes (2a, 2b). A flow rate output unit (6) calculates the flow rate of the fluid on the basis of the phase difference obtained by the signal conversion unit (5).

Abstract: In an electromagnetic flowmeter, a fluid to be measured flows through a measuring pipe. An electrode in the measuring pipe detects an electromotive force generated by a magnetic field applied to the fluid and flow of the fluid. A first exciting coil applies a first magnetic field having a first frequency to the fluid. A second exciting coil applies, to the fluid, a second magnetic field obtained by amplitude-modulating a carrier having the first frequency by a modulated wave having a second frequency. A power supply section supplies an exciting current to the first and second exciting coils. A signal conversion section separates the component of the first frequency from the electromotive force to obtain an amplitude, separates one of the components of sum and difference frequencies of the first and second frequencies from the electromotive force to obtain an amplitude, and obtains an amplitude ratio. A flow rate output section calculates the flow rate of the fluid on the basis of the amplitude ratio.

Abstract: A measurement pipe for an electromagnetic flowmeter includes a cylindrical pipe main body, a pair of flanges, and a lining material. The cylindrical pipe main body has openings at its two ends. The pair of flanges are integrally formed with the pipe main body to project outside the openings. The lining material is made of a reinforcing-material-mixed synthetic resin to cover at least an inner surface of the pipe main body and side surfaces of the flanges.

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: The invention consists in a capacitative electromagnetic flow meter in which excitation is performed at a frequency above the commercially available frequency and having a characteristic correction filter that corrects the gain frequency characteristic of the exciting current such that the exciting flux waveform has a flat section. In the detection unit, the value of the electrostatic capacitance between the face electrodes 4A, 4B and guard electrodes 5A, 5B is made smaller than the value of the electrostatic capacitance between the detecting face electrodes 4A, 4B and the fluid to be measured. The exciting coils are fixed to a cylindrical yoke, being electrostatically screened by coil fixing plates. Fixing by an earth ring is performed with this cylindrical yoke and the two ends of the measurement tube being symmetrical with respect to the tube axis and electrode axes. In addition, fixing is effected by filling the entire interior of the detection unit with epoxy resin.

Abstract: An electromagnetic flowmeter for measuring a flow rate in lines for conveying and distributing electrically conducting liquids, comprising a flowmeter body forming a substantially cylindrical open ended chamber, delimited by side walls of electrically insulating material. The flowmeter body accommodates a pair of facing electrodes arranged at diametrically opposite regions of said chamber and a magnetic field generator generating induction lines orientated at right angles to a line connecting the electrodes and to the chamber axis. The electrodes can be connected to a measuring device for measuring the potential difference induced between the electrodes by the fluid flow in the presence of said magnetic field. Two sleeves on the flowmeter body provide an extension of the chamber ends. The sleeves are flexible and fit hermetically over two duct portions along which the flow-rate is to be measured.

Abstract: In a borehole logging tool, the flow of conductive fluid into or out of a wellbore at the wellbore wall is detected and measured with a sensor loop proximate the borehole inner wall. The sensor loop includes a series of contiguous sensors that act as electromagnetic flowmeters and provide fluid measurements covering the entire circumference of the sensor loop. The sensor loop includes an elastic element that forces the sensor loop outward to maintain pressure along the sensor loop circumference against the interior borehole wall. The sensor loop is designed to lie at a non-perpendicular angle to the wellbore axis, and mechanical arms press the top and bottom of the loop against the borehole inner wall.

Abstract: Method for measuring the flow rate of a medium flowing through a measuring tube and which is penetrated by a constant magnetic field (B) orthogonal to the flow direction and in which the electrical voltage (UO) building up in the medium is sensed by means of electrodes (3, 3′), insulated with respect to the medium and located on the wall of the measuring tube (2) in a plane orthogonal to the flow direction of the medium, in which the capacitance of at least one capacitive unit (C) formed by the electrodes (3, 3′) and the tube interior and the charge change brought about by the change to the at least one capacitive unit (C) is determined and from this the voltage (UO) is established.

Abstract: A measurement pipe for an electromagnetic flowmeter includes a cylindrical pipe main body, a pair of flanges, and a lining material. The cylindrical pipe main body has openings at its two ends. The pair of flanges are integrally formed with the pipe main body to project outside the openings. The lining material is made of a reinforcing-material-mixed synthetic resin to cover at least an inner surface of the pipe main body and side surfaces of the flanges.

Abstract: A method for testing an electromagnetic flowmeter and a flowmeter are described, the flowmeter having a measuring tube (2) and a coil arrangement (3, 4) for generating a magnetic field perpendicular to the direction of flow through the measuring tube (2), the current direction in the coil arrangement being periodically changed. In this connection, it is desirable for simple monitoring to be possible. For that purpose, after changing the current direction, at least one parameter of the current rise is determined and this is compared with a reference value. For this, the flowmeter has a testing device (20, 25) which, after a change-over of the current direction, determines at least one parameter (T) of the rise in the current in the coil arrangement (3, 4, 30) and compares it with a given value.

Abstract: The invention consists in a capacitative electromagnetic flow meter in which excitation is performed at a frequency above the commercially available frequency and having a characteristic correction filter that corrects the gain frequency characteristic of the exciting current such that the exciting flux waveform has a flat section. In the detection unit, the value of the electrostatic capacitance between the face electrodes 4A, 4B and guard electrodes 5A, 5B is made smaller than the value of the electrostatic capacitance between the detecting face electrodes 4A, 4B and the fluid to be measured. The exciting coils are fixed to a cylindrical yoke, being electrostatically screened by coil fixing plates. Fixing by an earth ring is performed with this cylindrical yoke and the two ends of the measurement tube being symmetrical with respect to the tube axis and electrode axes. In addition, fixing is effected by filling the entire interior of the detection unit with epoxy resin.

Abstract: In a borehole logging tool, the flow of conductive fluid into or out of a wellbore at the wellbore wall is detected and measured with a sensor loop proximate the borehole inner wall. The sensor loop includes a series of contiguous sensors that act as electromagnetic flowmeters and provide fluid measurements covering the entire circumference of the sensor loop. The sensor loop includes an elastic element that forces the sensor loop outward to maintain pressure along the sensor loop circumference against the interior borehole wall. The sensor loop is designed to lie at a non-perpendicular angle to the wellbore axis, and mechanical arms press the top and bottom of the loop against the borehole inner wall.

Abstract: An electro-magnetic transducer interacts with a fluid in a tube and serves as either a flow sensor or as a pump. One or more electro-magnet(s) provide a magnetic flux transverse to a selected portion of the tube. The transducer has an electrically insulating sheet scrolled about an axis parallel to or coincident with that of the portion of the tube and extending from an axial streamlined body to an inner wall of the tube. One or more pair of electrodes are attached to the scroll so as to define a spiral electrical path between the two electrodes of the pair. These electrodes are connected to a voltage measurement circuit if the transducer is configured as a flow sensor or to a source of electric power if the transducer is configured as a pump. In addition, a flow commencement sensor is combined with the electro-magnetic flow sensor to provide a power-saving flow metering arrangement.

Abstract: In an electromagnetic flowmeter, a fluid to be measured flows through a measuring pipe. An electrode in the measuring pipe detects an electromotive force generated by a magnetic field applied to the fluid and flow of the fluid. A first exciting coil applies a first magnetic field having a first frequency to the fluid. A second exciting coil applies, to the fluid, a second magnetic field obtained by amplitude-modulating a carrier having the first frequency by a modulated wave having a second frequency. A power supply section supplies an exciting current to the first and second exciting coils. A signal conversion section separates the component of the first frequency from the electromotive force to obtain an amplitude, separates one of the components of sum and difference frequencies of the first and second frequencies from the electromotive force to obtain an amplitude, and obtains an amplitude ratio. A flow rate output section calculates the flow rate of the fluid on the basis of the amplitude ratio.

Abstract: In a borehole logging tool, the flow of conductive fluid into or out of a wellbore at the wellbore wall is detected and measured with a sensor loop proximate the borehole inner wall. The sensor loop includes a series of contiguous sensors that act as electromagnetic flowmeters and provide fluid measurements covering the entire circumference of the sensor loop. The sensor loop includes an elastic element that forces the sensor loop outward to maintain pressure along the sensor loop circumference against the interior borehole wall. The sensor loop is designed to lie at a non-perpendicular angle to the wellbore axis, and mechanical arms press the top and bottom of the loop against the borehole inner wall.

Abstract: The flowmeter comprises a flow sensor with a flow tube, two coils, and two measuring electrodes as well as measuring and control electronics. The method serves to compensate interfering potentials that are caused by inductive and/or capacitive interference arising from the coil leads and/or by particles of foreign matter or air bubbles in the liquid to be measured and/or by coatings on the measuring electrodes. During first subcycles of the excitation current, a measurement signal proportional to volumetric flow rate is computed as usual. During second subcycles of the excitation current, at least one voltage pulse is applied to at least one of the measuring electrodes.

Abstract: A magnetoinductive flowmeter for moving fluids, incorporating a sensor unit and a processing and power supply unit, the sensor unit encompassing a measuring tube, field coils which serve to generate a periodically alternating magnetic field in a direction at least essentially perpendicular to the axis of the measuring tube, and two measuring electrodes positioned along a line that extends at least essentially in a direction perpendicular to the axis of the measuring tube and perpendicular to the vector of the magnetic field, with field-coil feed lines connecting the field coils of the sensor unit to the processing and power supply unit. The sensor unit encompasses a sensor-data memory module in which specific parameters of the sensor unit are stored and from which the stored specific parameters can be transferred to the processing and power supply unit. This permits the simple adaptation of an existing sensor unit to a new processing power supply unit or vice versa.

Abstract: In order to reduce the influence of fluid velocity on a measurement of a concentration characteristic of a fluid, the magnitude of an r.m.s. signal V derived from a voltage induced in a sensor provided in relation to the fluid passage is adjusted using a factor dependent upon the measured velocity v of the fluid. Consequently, the accuracy with which the mass flow rate M of the solids in the fluid can be determined is improved.

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: An electromagnetic flowmeter arrangement is disclosed, having a measuring tube (2), a coil arrangement (3, 4) for generating a magnetic field substantially perpendicular to the direction of flow through the measuring tube (2), an electrode arrangement (5, 6) substantially perpendicular to the direction of flow and to the magnetic field, an evaluating device and a testing device. In this connection, it is desirable to be able to carry out testing in a simple manner. For that purpose, the testing device comprises a elements (10-13) for applying voltage to the coil arrangement (3, 4) without generating a magnetic field, and an element for determining an ohmic and/or inductive and/or capacitive coupling between the coil arrangement (3, 4) and the coil evaluating device.

Abstract: A device for measuring the rate of flow of fluids in a conduit is positioned within the conduit and includes a tube having two spaced part detectors which are separated by shielding units either side of them which are not in electrical contact with the detector units, when a variable electrical field is applied between the walls of the conduit and the shielding units the detector units detect discontinuities in the fluid, e.g., by detecting changes in the ratio of voltage to current and by correlating the movement of the discontinuities between the detector units, it is possible to measure the rate of flow of the fluid.

Abstract: The flowmeter comprises a flow sensor with a flow tube, two electrodes, and two field coils traversed by a first excitation current and a second excitation current, respectively, as well as control and evaluation electronics. The method serves to generate an error signal when the uniform turbulence in the liquid to be measured is disturbed. There are four quarter cycles. During each quarter cycle, a voltage is derived from the electrodes, and from these voltages, a first and a second voltage difference and a quotient using the first and the second voltage differences are formed. The latter is determined during calibration under uniformly turbulent flow conditions, and stored. In operation, values of the quotient are continuously formed and compared with the stored quotient; in case of deviations, an alarm is triggered and/or the volumetric flow rate signal represented by the first voltage difference is corrected.

Abstract: A collection reservoir 54 includes a rigid-walled cassette adapted for connection to aspiration tubing 50. The cassette also includes a pair of electrodes 36 positioned so that the electrodes are electrically connectable to a flow meter 34. In operation, the electrodes are exposed to the fluid and tissue being aspirated from the surgical site so that the flow meter indicates a flow rate of the fluid and tissue from the surgical site.

Abstract: A frequency measuring apparatus and a flowmeter which can carry out highly accurate measurement in a short time is provided. A measured pulse signal from a frequency detecting portion is outputted to a first counter as a count input and to second counter as a control signal. The first counter counts the number of the input pulse in each period of the first timer output according to the output from the first timer having been set in 1 second period, for example. The second counter carries out the count of the reference clock from the rising point of the input pulse and measures the period of the input pulse. The arithmetic processing portion calculates the input pulse signal frequency up to the decimal portion on the basis of the count value of the first counter, the count value of the second counter at a generation timing of the output signal from the first timer, and the period of the input pulse.

Abstract: Apparatus for measuring the rate of flow of a fluid in a conduit includes a receptor assembly arranged on the external surface of the conduit, and a removable external connector assembly including an electromagnet for establishing a magnetic field that extends transversely across the conduit, and a plurality of circumferentially arranged electrodes that are insertable into direct contact at their tips with the fluid in the conduit via sealable gland passages contained in the receptor assembly. A calibration adjustment arrangement is provided for adjusting the calibration factor of the flow signal processing system as a function of the conduit cross-sectional area. In a first embodiment, the glands are self sealable, whereupon the gland passages are automatically closed when the electrodes are removed therefrom.