GRID SENSOR, GRID SENSOR SYSTEM, METHOD AND COMPUTER PROGRAM PRODUCT FOR CORRECTING AN INTERFERENCE FROM ONE OR MORE FLUIDS

Description

[0001] Various embodiments relate to a grid sensor, a grid sensor system, a method and a computer program product, each of which is suitable for correcting a disturbing influence of one or more fluids on the grid sensor, the grid sensor system, measurement data of an evaluation device and measurement data of the computer program product.

[0002] In general, grid sensors can be used to investigate multiple components (e.g., phase components and / or fluid components) in a fluid stream, wherein the multiple components of the fluid stream differ in at least one electrical property.

[0003] For example, a capacitive grid sensor can be used to investigate fluid flow. The capacitive grid sensor can be used for small sensor areas (e.g., less than 10 cm²) and for a fluid flow that only contains components with low conductivity (e.g., in deionized water). For example, capacitive displacement currents can be measured using the transmit and receive wires of a grid sensor. Using an additional electrically non-insulated wire layer, all components of the conductive fluid can be connected to a ground potential, allowing these components to be set to ground potential (e.g., 0 V) on the signal side.

[0004] Conventional grid sensors may already be unsuitable for fluids that contain at least one conductive component (e.g., a conductive phase component and / or a conductive liquid component) with a higher conductivity than that of deionized water (e.g., tap water). For example, the conductive components can cause nonlinearities that can lead to signal loss along the receiver wires, e.g., due to energy dissipation. Signal losses can increase proportionally with the composition of the fluid stream (e.g., the conductivity of the conductive component of the fluid stream and / or the overall conductivity of the fluid stream) and / or with the properties of the transmitting and receiving wires (e.g., the length of the wires, the number of wires, the wire density, and / or the number of wire crossing points).The losses can depend on the respective wetting of the intersection points of the transmitting and receiving wires with the conductive portion of the fluid flow. Since the wetting of the intersection points can change continuously, the losses can also change continuously. In general, the losses can lead to nonlinearities and an underestimation of the measured values at all receiving wires in contact with the conductive fluid.

[0005] Even with a larger number of transmit and / or receive wires (e.g., more than 10 each) and / or larger geometries (e.g., a sensor area of more than 20 cm²), conventional grid sensors can only quantify the phase fractions or the liquid fractions inaccurately or not at all. For example, precise calibration of all sensor elements, especially with a larger number of transmit and / or receive wires, can be very difficult to achieve. Conventional grid sensors may be unsuitable for quantifying phase fractions or liquid fractions as long as the conductive phase is the continuous phase.

[0006] DE 10 2013 203 437 describes a grid sensor for measuring the phase distribution of a multiphase mixture with gaseous and liquid components in the presence of a highly conductive phase (such as salt water or liquid metal).

[0007] WO 2021 053 177 describes a multiphase measurement system for a multiphase fluid comprising a reference value measurement arrangement and a multiphase measurement device. The reference value measurement arrangement has at least one capillary and a capillary measurement device. The internal cross-sectional area and length of the capillary are dimensioned such that, when flowing through the capillary, phases of the multiphase fluid separate in the flow direction. The capillary measurement device is configured to determine at least one physical property of at least one of the phases flowing through the capillary.

[0008] According to various aspects, a device and a method are provided that enable the measurement of a fluid flow that may comprise multiple phase components and / or multiple fluid components. At least one phase component of the multiple phase components or one fluid component of the multiple fluid components may be (highly) conductive.

[0009] According to various aspects, an apparatus and method is provided that can compensate for losses and nonlinearities at transmitting electrodes and / or receiving electrodes due to wetting with a conductive portion of the fluid flow.

[0010] According to various aspects, a method is provided that can inherently quantify the losses and nonlinearities.

[0011] According to various aspects, a method is provided that determines one or more corrected or loss-free measured values from one or more measured (e.g., lossy) values of the individual crossing points of the transmitting and receiving electrodes in the fluid flow and one or more reference values. The one or more corrected or loss-free measured values can correspond to the actual measured values at the crossing points.

[0012] According to various aspects, a device and a method are provided which make it possible to use a capacitive grid sensor also for a fluid flow which has at least one highly conductive phase component or fluid component.

[0013] According to various aspects, a device is provided that can be used to correct the energy losses in the receiving wires of a grid sensor. For example, this can enable measurement of conductive and / or highly conductive liquids.

[0014] According to various aspects, an apparatus is provided that can be used to measure multiphase mixtures in which at least one of the phases is conductive and / or highly conductive.

[0015] According to various aspects, a method is provided that enables estimation and compensation of energy losses in grid sensors when the grid sensor is used to measure conductive and / or highly conductive fluids (e.g., gases and / or liquids).

[0016] According to various aspects, a method is provided that enables the correction of nonlinearities in measurements. This allows, for example, the accuracy of a grid sensor to be increased in the determination of flow-dependent parameters, e.g., in the determination of a fractional portion (e.g., a percentage of a phase and / or a liquid in the total fluid flow) and / or a respective flow velocity of one or more phases of the fluid flow, and / or a phase velocity and / or one or more concentration ratios (e.g., of mutually different portions within the fluid, e.g., in the context of a so-called tracer measurement).

[0017] According to various aspects, a grid sensor can be provided comprising: a fluid guide region; a plurality of grid sensor units, wherein each of the plurality of grid sensor units comprises: a group of sensor elements configured to generate measurement signals representing one or more properties of a fluid guided in the fluid guide region; an electrode, wherein the sensor elements of the group of sensor elements are connected to the electrode for operating the sensor elements of the group of sensor elements; a reference element which is assigned to the electrode, is connected to the electrode, and is configured to provide a reference signal representing a disturbing influence of the fluid guided in the fluid guide region on an electrical characteristic of the electrode.

[0018] Thus, a device is clearly provided in various aspects that can inherently quantify losses and nonlinearities. The reference element, which is not influenced by the fluid flow, can provide a reference value that can represent a signal from an electrode. Since both the geometry and the materials are unchanged, measurable changes in the reference value can be attributed to a change in the signal (e.g., a signal loss or a signal gain) along a respective electrode (e.g., transmitting electrode and / or receiving electrode).

[0019] According to various aspects, the reference electrode can be arranged in a base plate of the grid sensor. For example, the reference electrode can determine (e.g., measure) a reference value (e.g., a capacitance, a temperature, an inductance) using a carrier material (e.g., a circuit board).

[0020] According to various aspects, a grid sensor system can be provided, comprising: a grid sensor according to one of claims 1 to 8, a determination device configured to determine the reference signal and to determine the measurement signals, and wherein a measurement signal of the measurement signals is assigned to a sensor element of the group of sensor elements.

[0021] According to various aspects, a grid sensor system can comprise: a fluid guide region for guiding a fluid; an electrode arranged in the fluid guide region; a reference signal source (e.g., the reference transmitting electrode excited by a voltage source providing a reference excitation voltage) for generating a reference signal (e.g., a reference current or a reference voltage) in the electrode; a reference signal receiver for receiving the reference signal (e.g., as a current or voltage); and a signal evaluation unit for evaluating the received reference signal, wherein the received reference signal represents a disturbing influence of the fluid flowing in the fluid guide region on an electrical characteristic of the electrode. It is understood that a reference signal in the form of a voltage can be assigned to a current and vice versa, for example, by means of a resistor.

[0022] According to various aspects, an evaluation device (e.g. measuring device) can comprise: an input interface which is configured to receive measurement data and reference data from a grid sensor according to one of claims 1 to 8, wherein the grid sensor can be at least partially flowed around by one or more fluids, wherein the measurement data represent at least one property of the one or more fluids and have a disturbing influence of the one or more fluids on the grid sensor, and wherein the reference data represent the disturbing influence of the one or more fluids on the grid sensor; one or more processors which are configured to carry out a measured value correction for creating corrected measurement data based on the measured data and the reference data, wherein the measured value correction corrects the disturbing influence of the one or more fluids on the grid sensor;and an output interface for outputting the corrected measurement data, which represent at least one property of the one or more fluids and are independent of the disturbing influence of the one or more fluids on the grid sensor.;

[0023] According to various aspects, a computer program product may include instructions that cause one or more processors to perform the following: loading a data set comprising a calibration value, a first group of measured values, and a first reference value, wherein the calibration value represents a calibration disturbance influence of exactly one fluid of one or more fluids on a group of sensors, wherein the first reference value represents a first disturbance influence on the group of sensors by the one or more fluids, wherein each measured value of the first group of measured values represents a property of the one or more fluids and the first disturbance influence on the group of sensors, and wherein each measured value of the first group of measured values is associated with one sensor of a group of sensors; determining a correction value from the calibration value and the first reference value;and correcting each measured value of the first group of measured values using the correction value. For example, the influence of only air on the electrode can be considered interference-free, since this does not cause a substantial current flow from the electrode (e.g., less than 0.1% of the total flow). For example, under this consideration, the calibration value can be measured without interference if the electrode is only exposed to air. Depending on the measurement setup, other conditions can also define a corresponding calibration value as interference-free, e.g., one of several fluids to be measured, which has the lower interference influence.

[0024] Embodiments are shown in the figures and are explained in more detail below.

[0025] It shows Figures 1A to 1C each show a schematic representation of one or more groups of sensor elements of a grid sensor according to various aspects; Figures 2 to 3B each show a schematic representation of various grid sensors according to various aspects; Figures 4 to 6 each show a method for correcting one or more measured values of a grid sensor according to various aspects; Figure 7 each show a schematic representation of various electrode segments of a grid sensor according to various aspects; and Figures 8 and 9 each show a schematic representation of various grid sensors according to various aspects.

[0026] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced.

[0027] According to various aspects, fluids, components of a fluid (e.g., phase components and / or fluid components), and / or components can be described as electrically conductive (or, for short, as conductive). Media with a conductivity of more than 0.1 µS / cm (e.g., more than 1 µS / cm, 100 µS / cm, 400 µS / cm) are referred to as conductive. Electrically conductive media with an (electrical) conductivity of more than 500 µS / cm (e.g., more than 1000 µS / cm, 10,000 µS / cm, 50,000 µS / cm) can be referred to as highly electrically conductive (or, for short, as highly conductive).

[0028] According to various aspects, one or more fluids can flow through one or more components, or along or past one or more components. Each of the one or more fluids can have a flow velocity and can be referred to as a fluid stream or flowing fluid. It should be noted that any fluid can also refer to a fluid stream. Furthermore, it should be noted that, in the following, "a fluid" can also refer to "one or more fluids" (e.g., a mixture of one or more fluids), unless explicitly stated otherwise or if this is clear from the context. According to various aspects, each fluid of one or more fluids can have one or more components (e.g., one or more components, and / or multiple components that differ from one another in at least one property (e.g., a temperature, a density)). A component can also be referred to as a phase.A portion of a fluid can, for example, be a state of aggregation of a portion of the fluid (e.g., solid, liquid, and / or gas). A fluid can be a liquid, and / or a gas, and / or a fluidized solid. For example, one or more fluids can comprise one or more liquids. For example, one or more fluids can comprise one or more gases. For example, one or more fluids can comprise one or more gases and one or more liquids. For example, one or more different fluids can have at least one different property. Each of the one or more fluids can have one or more of the following properties: a temperature, a pressure, a viscosity, an electrical property (e.g.,an electrical conductivity, an impedance, a relative permeability, an electrical charge), a magnetic property, a state of aggregation, an atomic number, a chemical composition, and / or a velocity (e.g., a flow velocity). For example, the fluid may also contain one or more solids, e.g., in the form of solid particles (e.g., with a diameter of less than 0.5 cm, 0.1 cm, or less than 0.01 cm), provided that the overall properties of such substances or mixtures of substances (e.g., emulsions, e.g., sand, or similar) have a fluid character.

[0029] For example, a percentage of a fluid or fluid flow can be a mass (or volume) of a portion relative to the total mass (or volume) of the fluid. For example, all percentages can sum to 100%.

[0030] According to various aspects, signals are processed, e.g., sent, received, manipulated, modified, etc. A signal that is sent by means of an electrode (e.g., a transmitting electrode) can be referred to as a transmitted signal or transmitted signal. A signal that is received by means of an electrode (e.g., a receiving electrode) can be referred to as a received signal, received signal, or measured signal. Between the transmission of the signal from a signal origin via the transmitting electrode and the reception of the signal at a signal destination, the signal can be modified by one or more interactions, e.g., with the one or more fluids and / or with components of the grid sensor, before it can be received. Without an interaction, the received signal can be the same as the transmitted signal (i.e., no difference occurs). For example, the electrode can be wire-shaped (e.g., a wire). For example, the electrode can be sword-shaped.For example, the electrode can be plate-shaped. For example, the electrode can be a conductor track on a circuit board. For example, an electrode can be held in half sections (e.g., on a substrate (e.g., a circuit board)). For example, the electrode can be exposed between two (e.g., adjacent) holding sections. For example, the electrode can have no contact with solid material (e.g., the substrate, e.g., the circuit board) in sections between two (e.g., adjacent) holding sections. This allows a fluid to be measured to reach an area of the electrode.

[0031] The interactions can create at least one difference between the transmitted and received signals. The difference can, for example, represent at least one property of the one or more fluids and / or of at least one of the components of the grid sensor. The difference can, for example, additionally (or entirely) represent one or more disturbing influences. Each of the disturbing influences can, for example, increase or decrease the difference. For example, different disturbing influences of the one or more disturbing influences can compensate for each other. Disturbing influences can be unwanted and potentially render the measurement results of a sensor unusable.

[0032] According to various aspects, reference elements can be used to determine interference. For example, a reference element can be a component that outputs a constant and / or predetermined or predefined output signal depending on an input signal (a so-called excitation signal). For example, the reference element can generate the output signal. For example, the reference element can be a passive component that has a known transfer function between a first and a second electrode. Illustratively, the reference element can output the input signal, which can be provided by a first electrode at the reference element, with a known transfer function (which can lead, for example, to a known change) as the output signal of the reference element from the reference element, e.g. to a second electrode.It is understood that the reference element can be designed such that the output signal is equal to the input signal. For example, the input signal can be changed within the reference element in a predetermined manner and output with the predetermined change as an output signal. Interference can change the output signal of the reference element and be received as a reference signal. For example, the output signal can have one or more predetermined or predefined properties of the following: a current, a voltage, a resistance, a frequency, a wavelength, an intensity, a duration, a temperature, etc. The signal output by the reference element can be received as a reference signal. The reference signal can be changed compared to the output signal, for example, due to the interactions described above.The reference signal can be understood as the output signal under the influence of the disturbing influences. For example, one or more disturbing influences can be estimated by comparing the output signal and the reference signal. For example, several (e.g., different) reference elements can be used to determine various disturbing influences. For example, a reference signal determined under a predetermined condition (e.g., a filling condition) can be referred to as a calibration signal. For example, one or more reference values can be derived from a reference signal. For example, one or more calibration values can be derived from a calibration signal.

[0033] According to various aspects, a grid sensor may include one or more sensor elements. For example, a sensor element may be coupled to a first electrode and a second electrode. For example, a transmit signal may be transmitted from the first electrode within the sensor element to the second electrode. A sensor element may, for example, provide a capacitive coupling and / or an ohmic coupling between the first and second electrodes. For example, the sensor element may include or consist of one or more of the following components: a resistor, a capacitor, a coil, a temperature sensor, a light source, a photodetector, and / or a pressure sensor, or a combination thereof. The reference element may include or be one or more sensor elements.

[0034] Fig.1A is a schematic representation of a grid sensor unit of a grid sensor. The grid sensor can have: a fluid guide region 130, a group of sensor elements 120, an electrode 110, and a reference element 140. The fluid guide region 130 can be suitable for guiding a fluid or a fluid flow. For example, the group of sensor elements 120 can be suitable for determining one or more properties of the fluid (or the fluid flow) when the fluid is guided or flows through the fluid guide region 130. The sensor elements of the group of sensor elements 120 can be connected to the electrode 110 to operate the sensor elements of the group of sensor elements 120. Operation can be understood as reading out, supplying (e.g., with energy), and / or performing a measurement using the respective sensor element. The reference element 140 can be assigned to the electrode 110.For example, the reference element 140 can be configured to provide a reference signal for determining correction data, which can represent a disruptive influence of the fluid on an electrical characteristic (e.g., a resistance, an impedance, a capacitance, and / or an inductance) of the electrode 110 when the fluid is guided in the fluid guide region 130. The reference element 140 can, for example, be arranged outside the flow region 130. For example, the reference element 140 can be configured such that a predefined (or predetermined and / or known) output signal, which is output (e.g., transmitted) and / or generated by the reference element 140, is not influenced within the reference element 140 by a fluid flowing in the flow region.Illustratively, this means that the predefined output signal output by the reference element is independent of the fluid conveyed in the fluid guidance region. For example, the reference element 140 can be at least partially covered with a protective layer. For example, the protective layer can shield the reference element from one or more influences of the fluid flowing in the flow region. After the predefined output signal is output from the reference element 140, the predefined output signal can be modified by the influences of the fluid flowing in the flow region. The modified output signal can be received as the reference signal.

[0035] Fig.1B is a schematic representation of a grating sensor unit of a grating sensor. In comparison to the grating sensor according to Fig.1A The grid sensor indicates Fig.1B several further electrodes 150 and a reference electrode 151. The several further electrodes 150 can be located in a different plane compared to the electrode 110. For example, the electrode and the several further electrodes can be / are electrically insulated from each other.

[0036] In a projection view of the grid sensor, the electrode 110 and the plurality of further electrodes 150 can intersect at at least one point. For example, a sensor element can be arranged at the intersection point. For example, the sensor element can also be formed by the intersection point. The intersection angle can be selected arbitrarily between 0° and 180°. Projections with intersection angles of 90° are often shown below. The plurality of further electrodes 150 can have a plurality of first further electrodes 150a, which can be arranged parallel to one another, for example. The plurality of further electrodes 150 can, for example, have at least one second further electrode 150b. The second further electrode 150b can, for example, not be arranged parallel to the electrodes of the first type 150b. It is understood that the further electrodes 150 can generally be arranged arbitrarily relative to one another and to the electrode 110.However, to ensure optimal functionality of the grid sensor, electrodes that are not intended to interfere with each other should be electrically shielded from each other, e.g., by means of a suitable arrangement of the electrodes and / or insulating materials. It is understood that the electrodes can be electrically connected to each other via the fluid flowing through the flow region.

[0037] The reference element 140 can be connected to the electrode 110. The reference element 140 can be connected to a reference electrode 151. The reference electrode 151 can, for example, be arranged such that it is not influenced by a fluid in the fluid-conducting region. For example, the reference electrode 151 can be arranged outside the fluid-conducting region 130. For example, the reference electrode 151 can be (at least partially) enclosed such that it is not influenced by the fluid. Illustratively, the electrode 110, the reference element 140, and the reference electrode 151 can be configured such that a reference signal can only be changed by an influence of the fluid on the electrode 110. For example, the reference electrode 151 can be one of the several further electrodes 150. For example, the reference electrode 151 can be arranged within the fluid-conducting region 130.

[0038] Each sensor element of the group of sensor elements 120 can be connected both to the electrode 110 and to one of the several additional electrodes 150. Clearly, each sensor element can have a connection to the electrode and to one of the several additional electrodes 150.

[0039] For example, the electrode 110 can be configured to transmit a signal (ie, configured as a transmitting electrode). For example, the reference electrode 151 and / or the plurality of further electrodes 150 can each be configured to receive a signal (ie, as receiving electrodes).

[0040] To determine a corrected measurement signal, the grid sensor can, for example, be configured to transmit a predetermined transmission signal to the reference element 140 via the electrode 110. By means of the reference element 140, the predetermined signal can be transmitted as the reference signal to the reference electrode 151 (illustratively, forwarded essentially unchanged). For example, the reference element 140 can transmit an output signal of the reference element 140 to the reference electrode 151 via the predetermined signal. The output signal can be modified (e.g., amplified or attenuated) by the influence of a fluid conducted in the fluid region. The signal received by the reference electrode 151 can be the output signal modified by the influence of the fluid conducted in the fluid region 130.

[0041] For example, the electrode 110 can be configured to transmit a signal (i.e., a transmission signal). The plurality of further electrodes 150 can be configured such that only one of the plurality of further electrodes 150 can receive the transmission signal via the respective sensor element. The plurality of further electrodes 150 can be configured such that all of the plurality of further electrodes 150 can receive the transmission signal via the respective sensor element, e.g., simultaneously or within 1 second after a first of the plurality of further electrodes 150 has received the transmission signal. For example, the plurality of further electrodes can be configured such that, after a first electrode has received a first measurement signal, a second electrode can receive a second measurement signal.For example, such a change of the respective receiving electrodes can be carried out until a predetermined number or a predetermined amount of electrodes have each received a measurement signal.

[0042] For example, the electrode 110 can be configured to receive a signal (ie, configured as a receiving electrode). For example, the reference electrode 151 and the plurality of further electrodes 150 can each be configured to transmit a signal (ie, as transmitting electrodes).

[0043] To determine a corrected measurement signal, the grid sensor can, for example, be configured to transmit a reference transmission signal to the reference element by means of the reference electrode 151. Within the reference element 140, the signal can be transmitted as the reference signal to the electrode 110. For example, the first further electrodes 150a can be configured to transmit a first transmission signal of the one or more transmission signals. For example, the second electrode can be configured to transmit a second transmission signal. For example, the first and second transmission signals can be identical in all signal properties. For example, the first and second transmission signals can differ in at least one signal property. A signal property can, for example, be a duration, an intensity, a wavelength, a frequency, an on-time, and / or an intensity curve.

[0044] For example, one of the first further electrodes 150a can transmit the first transmission signal. After a predetermined first time interval, a second of the first further electrodes 150a can transmit the first transmission signal. After a predetermined second time interval, the second further electrode 150b can transmit the second transmission signal. Illustratively, the first and second time intervals can be referred to as first and second pauses, respectively. For example, the first and second time intervals can be of equal length or different lengths. For example, a sequence of multiple signals and / or multiple pauses can be referred to as a signal sequence. For example, a number of signal sequences per second can be referred to as a signal sequence frequency. The electrode 110 can be configured to receive a respective transmitted signal as a measurement signal via a respective sensor element.Such a procedure can be continued analogously until a predetermined number of the several further electrodes 150 have sent a signal.

[0045] Whether the electrode is configured as a receiving electrode or a transmitting electrode, the respective measured values can be corrected using the reference signal. It goes without saying that determining a measurement signal can also take place alternately with determining the reference value. Of course, it is also possible to determine several or all measured values and determine the reference value before or after.

[0046] As is clear from the previous embodiments, the reference element can be used on both transmitting and receiving electrodes. Furthermore, it is possible to couple multiple electrodes together via different sensor elements. The sensor elements are preferably arranged in a matrix arrangement, i.e., evenly spaced from one another. However, it is also possible to arrange the sensor elements in any desired order. Since a matrix arrangement appears more suitable for systematic evaluation, a specific embodiment is shown below:

[0047] Fig.1C is a schematic representation of multiple grid sensor units of a grid sensor according to various aspects, wherein each grid sensor unit can be assigned to an electrode 110. Each grid sensor unit can have at least one reference element 140. The reference element 140 of the respective grid sensor unit can be assigned to the respective electrode 110 of the grid sensor unit. The reference elements 140 of the multiple grid sensor units can be connected to a reference electrode 151. It is understood that each reference element 140 can be connected to a reference electrode 151 that has no connection to the reference elements 140 of the other grid sensor units. Each grid sensor unit of the grid sensor can have a group of sensor elements 120. Each group of sensor elements 120 can be assigned to a respective electrode 110 of the grid sensor. The grid sensor can have a plurality of further electrodes 150.The plurality of further electrodes 150 can each connect one sensor element of a plurality of grid sensor elements to one another. Each of the plurality of further electrodes 150 can thus form a further group of sensor elements 125. Clearly, each sensor element 120 of the grid sensor can be assigned to a group of sensor elements 120 and to a further group of sensor elements 125. For example, a sensor element can thus be precisely assigned a transmitting electrode and a receiving electrode. The assignment to the group of sensor elements 120 via the (e.g., common) electrode 110 can also be understood as an assignment to a grid sensor unit.

[0048] Fig.2 is an extended schematic representation of the grid sensor according to Fig.1C The grid sensor can have multiple grid sensor units. Each grid sensor unit can have an electrode 110, a group of sensor elements 120, one or more reference electrodes, and one or more reference elements 140. Furthermore, the grid sensor can have a plurality of further electrodes 150, wherein each of the plurality of further electrodes 150 can connect a sensor element of different grid sensor units of the plurality of grid sensor units to one another. Sensor units that are connected to one another by means of one of the further electrodes 150 can be assigned to a group of further sensor units 125. Due to the plurality of further electrodes 150, several groups of further sensor units 125 can thus be formed. For example, each of the four electrodes 110 shown as an example can be connected to a first reference element 140a and a second reference element 140b.The respective first and second reference elements 140a, 140b can be coupled to mutually independent reference receiving electrodes 151 of a plurality of reference receiving electrodes 151. For example, each of the four exemplary further electrodes 150 of the plurality of further electrodes can be connected to a third reference element 140c and a fourth reference element 140d. The third and fourth reference elements can each be coupled to a mutually independent reference transmitting electrode 111 of a plurality of reference transmitting electrodes 111.

[0049] For example, each of the multiple grid sensor units can be coupled to a transmission circuit 210, e.g., via the respective electrodes 110 and the respective reference transmission electrodes 111. The transmission circuit 210 can be configured to transmit one or more signals via the respective electrodes 110 and / or the respective reference transmission electrodes 111. For example, the grid sensor can be connected to or comprise a voltage source 220, e.g., an AC voltage source.

[0050] For example, the plurality of grid sensor units can each be coupled to a receiving circuit, e.g., by means of the further electrodes 150 and the reference receiving electrodes 151. The receiving circuit can, for example, comprise one or more signal amplifiers 230 for amplifying a received (e.g., incoming) signal. The receiving circuit can, for example, comprise one or more log-amp circuits 240 for converting a respective received signal into a logarithmically scaled signal. The receiving circuit can be configured to receive one or more signals by means of the plurality of further electrodes 150 and / or the plurality of reference receiving electrodes 151. The receiving circuit can be configured to forward received signals to a detection device 250.

[0051] The determination device 250 can, for example, be configured to store received measurement signals. For example, the grid sensor can have a calculation device configured to correct the measurement signals using reference signals.

[0052] Fig.3A shows two schematic sectional views of a grid sensor. For example, in Fig.3A It can be seen that the electrode 110 and the further electrodes 150 can be arranged in different planes. The upper view of Fig.3A shows a first sectional view along a circuit board 310, in which, for example, one or more electronic circuits can be configured. The lower view shows a second sectional view through the fluid guide area 130.

[0053] Fig.3B shows a three-dimensional schematic measurement setup of a grid sensor and an equivalent circuit 350. The grid sensor is schematically shown with a section through a fluid guide region 130 (e.g., in the form of a tube). The equivalent circuit 350 illustrates a circuit that is implemented, for example, by a single sensor element. A connection can be established between an electrode 110 and another electrode 150 within the sensor element, e.g., via the fluid, which can have an impedance Z x . However, the impedance Z x can also be implemented by a real component between the electrode 110 and the other electrode 150.

[0054] The grid sensor may further comprise a control device 320 configured to transmit a signal sequence via the electrodes 110 and to receive it via the further electrodes 150.

[0055] Errors in the measurement signals or measured values, which can be detected in the form of energy losses, can be corrected, for example, using the following procedure.

[0056] Energy losses of grid sensor electrodes can be estimated using reference values (e.g., reference impedances, reference capacitances), which can be determined using reference elements located outside the detection range of the grid sensor. Each electrode can be connected to a reference element. A reference element can be formed, for example, as a copper conductor in a printed circuit board layout. For example, a reference element can be a discrete component such as a resistor, a capacitor, an inductor, a temperature sensor, and / or a semiconductor, or combinations of the above.

[0057] A first measurement (e.g., a first calibration measurement) can be performed with the sensor completely filled with air. The output signal of the reference element can be stored. In the case of a small energy loss (e.g., less than 5%, 2%, 1%, 0.5%, 0.1%, or less than 0.01%) of one or more electrodes (e.g., the transmitting electrodes and / or the receiving electrodes), a received reference signal can be equal to the output signal of the reference element. In such a case (small energy loss), the reference signal would represent that the one or more electrodes are (almost) free of any interference (e.g., if the fluid guide region is completely filled with air or a similar gas or gas mixture (i.e., with a relative electrical dielectric constant between 0.1 and 5), or if a vacuum prevails therein). All calibration signals, including the reference signal that represents no interference, can be stored.Using a suitable algorithm, the energy losses of one or more electrodes can be estimated and corrected taking into account the calibration signals (e.g., the reference signal or, for example, the reference signals). This can be done, for example, by relating the reference signals, e.g., of a sensor free from interference, to new reference signals that may represent a sensor with interference. The new reference signals can be determined during a specific measurement. Thus, for example, a method can be provided that can be used for time-resolved and / or image-resolved (i.e., frame-by-frame) measurements (e.g., determination of interference).

[0058] For example, a measured value can be subjected to a measurement value correction with linear demodulation, as described below.

[0059] The matrix of measured output voltages U o x is a measure that can represent the output voltage of each crossing point of the fluid flow cross section of the fluid x. It can be represented as U o mess , x i j k = U o ideal , x i j x ξ i k where U o ideal , x an ideal measurement within the fluid x, i.e., without a loss, and ζ represents one or more losses of each electrode i. The indices i and j represent the electrodes (e.g., receiving electrodes and transmitter electrodes), and k is a consecutive number of a measurement. For example, k can be used for a correct assignment of the different measurements (e.g., as measurement identification). For example, the number k can be used to output a time-resolved and / or image-resolved (i.e., frame-by-frame) corrected measurement result. Assuming that the losses of the electrodes are negligible when the sensor is completely filled with air, the ideal output voltage U o ideal , Luft approximately by measuring the output voltage in a calibration medium (e.g. in air ζ ≈ 1) U o mess , Luft can be estimated as follows: Based on this property, the signals of the external references for each receiver i can be collected before a particular experiment. For example, when no disturbances occur (e.g., when the sensor is filled with air). Then stored data U o meas , x i 0 k of reference elements at j = 0 to calculate the energy losses ξ ( i,k ) for each further experiment as follows (e.g. in real time): ζ i k ≈ ζ ˜ i k = U mess , Luft i 0 k U mess , x i 0 k , where ζ̃ is an estimate of a real loss ζ and the index j = 0 denotes one or more reference elements (e.g., intersection points of the electrodes outside the fluid flow area of the grid sensor). Since the reference elements can have a constant impedance, they are only affected by the losses caused by the electrically conductive parts of the fluid flow in the fluid flow area. The corrected measured output voltages U x< korrigiert can therefore be given by: U mess , x korrigiert i j k = U mess , x i j k ζ ˜ i k .

[0060] The measured value correction with linear demodulation can be transferred to a measured value correction with log-amp demodulation.

[0061] For example, the matrix of the logarithmic measured output voltages U x< log for an ideal (i.e., fault-free) condition, taking into account the above relationships, can be calculated as follows: U o log ideal , x i j k = v a . log U o ideal , x i j k v b where v a and v b Constants of the log amp circuit.

[0062] Assuming that the output voltages can be changed by disturbances, the following results: U o log mess , x i j k = v a . log U o ideal , x i j k ξ i k ⋅ 1 v b = v a . log U o ideal , x i j k v b − v a . log ξ i k .

[0063] As with linear demodulation, it can be assumed that loss due to a disturbance in an air-filled grid sensor is negligible, which means that v a . log U o mess , Luft i j k v b − 0 ≈ v a . log U o ideal , Luft i j k v b .

[0064] The loss due to the disturbance can be calculated using an external reference: v a . log ξ ˜ i k = log U o mess , Luft i 0 k − log U o mess , x i 0 k , where j=0 represents the position of the reference.

[0065] Thus, the entire measurement value correction of the output voltages U o_log korrigiert mess , x i j k within the fluid x at the positions i,j and the measurement k be given by: U o_log korrigiert mess , x i j k ≈ U o log mess , x i j k + v a . log ξ ˜ i k .

[0066] In the Figuren 4 bis 6 various exemplary designs of the procedures for measured value correction are described.

[0067] Fig.4 shows a schematic of a method for calibrating a grid sensor.

[0068] In a first step, a calibration value and one or more calibration measured values can be determined under the influence of a first fluid (S410). For example, the calibration value and the calibration measured values can represent a state of the grid sensor in which a first fluid completely fills the fluid guide area of the grid sensor. The first fluid can be, for example, a gas or a liquid.

[0069] Then, a further calibration value and one or more further calibration measured values can be determined under the influence of a second fluid (S420). For example, the further calibration value and the one or more further calibration measured values can represent a state of the grid sensor in which a second fluid completely fills the fluid guide area of the grid sensor. The second fluid can, for example, have a higher relative permeability than the first fluid. For example, the second fluid can be a liquid.

[0070] Then a correction value can be calculated using the calibration value and the further calibration value (S430).

[0071] In a final correction step, the one or more calibration measured values and / or the one or more additional calibration measured values can be corrected (S440). Based on the one or more calibration measured values and the correction value, one or more corrected calibration measured values can be determined (e.g., calculated). Based on the one or more additional calibration measured values and the correction value, one or more additional corrected calibration measured values can be determined (e.g., calculated).

[0072] The one or more corrected calibration measured values or the one or more further corrected calibration measured values can be further evaluated using common methods to determine electrical properties of the fluid to be tested.

[0073] For example, the described method can be used to estimate the magnitude of a disturbance. For example, the described method can be used to scale measured values.

[0074] Fig.5 shows schematically a method for correcting one or more measured values, e.g. from a reference element and a measurement from several sensor elements connected to this reference element.

[0075] A calibration value and one or more first calibration measured values can be determined under the influence of a first fluid (S510). For example, the calibration value and the calibration measured values can represent a state of the grid sensor in which a first fluid completely fills the fluid guide area of the grid sensor.

[0076] Subsequently, a first reference value can be determined under the influence of the first fluid and a second fluid (S520). For example, the first reference value can represent a state of the grid sensor in which at least a second fluid, in addition to the first fluid, is present in the fluid-conducting region of the grid sensor. This step can, for example, represent the start of a measurement.

[0077] Then, one or more first measured values can be determined under the influence of the first fluid and a second fluid (S530). For example, the one or more first measured values can represent a state of the grid sensor in which at least a second fluid, in addition to the first fluid, is present in the fluid-conducting region of the grid sensor. This step can, for example, represent a measurement of the fluid in the fluid-conducting region.

[0078] Based on the determined values, a correction value can be calculated based on the calibration value and the first reference value (S540).

[0079] In the final step, one or more first corrected measured values can be calculated using the correction value and the one or more first measured values (S550).

[0080] The corrected measured values can be further evaluated using common methods, for example, to determine fluid properties. If the measurement is not yet complete, the procedure can be repeated starting with the determination of the first reference value (S560).

[0081] Fig.6 shows schematically another method for correcting a measured value, similar to that of Fig.5 In contrast to the procedure under Fig.5 In this method, a new reference value is determined between each measured value. This allows for greater accuracy, for example, when very fast measurement electronics are available. For example, the measured value and the reference value can be determined simultaneously or within less than 50 ms (e.g., less than 10 ms, 1 ms, or less than 0.1 ms). For example, only the transmitting electrodes can be switched sequentially. This allows for constantly new reference and measured values to be obtained, which can be evaluated in a combined analysis.

[0082] For example, energy loss can occur at the transmitting electrode if the material of an electrode is a poor conductor (e.g., stainless steel) and one of the phases present in the flow region is highly conductive. In this case, a high current flow occurs at the transmitting electrode, which initially causes a significant voltage drop across the electrode.

[0083] The energy loss at the transmitting electrode can be estimated by representing the measuring system as an equivalent circuit, as in Fig.7 shown.

[0084] In Fig.7 represents R x (x=1, 2, 3, ..., n+1) the resistance of an electrode segment, which is R x = L x σA cr is calculated, where L x is the length of a segment of the transmitting electrode, σ the electrical conductivity of the electrode and A cr is the cross-sectional area of the electrode. Z x is the impedance of the fluid associated with the crossing point x, which in turn can be theoretically estimated as Z x = 1 1 σ x + jωε o ε x , where σ x and ε x the electrical conductivity or the relative permittivity of the fluid, ω the angular frequency and j = − 1 .

[0085] U Tx,in and U Tx,out are the reference voltages. They can be obtained using two approaches.

[0086] In the first approach, U Tx,in and U Tx,out analogous to the procedure for correcting the energy losses of the receiver wires from external references 810 ( Fig.8 ).

[0087] In the second approach, U Tx,in equal to the voltage source (which is known a priori), and U Tx,out is measured individually by an operational amplifier ( Fig.9 ).

[0088] The energy losses along the electrode are formulated based on Ohm's law and Kirchhoff's law: U Tx , 1 Z 1 + U Tx , 1 − U Tx , in R 1 + U Tx , 1 − U Tx , 2 R 2 = 0 U Tx , 2 Z 2 + U Tx , 2 − U Tx , 1 R 2 + U Tx , 2 − U Tx , 3 R 3 = 0 ⋮ U Tx , n Z n + U Tx , n − U Tx , n − 1 R n + U Tx , 2 − U Tx , out R n + 1 = 0 .

[0089] For simplicity, it can be represented in matrix form as follows p 1 − q 2 0 0 … 0 0 0 − q 1 p 2 − q 3 0 0 0 0 ⋮ ⋱ ⋮ 0 0 0 0 − q n − 2 p n − 1 − q n 0 0 0 0 … 0 − q n − 1 p n U Tx , 1 U Tx , 2 ⋮ U Tx , n − 1 U Tx , n q 1 . U Tx , in 0 ⋮ 0 q n . U Tx , out where, p x = 1 Z x + 1 R x + 1 R x + 1 , q x = 1 R x .

[0090] The matrix form of the energy losses along the electrode shows a linear system of the type Ax = b, where the energy loss by solving the linear system is x = A -1< b The matrix form of the energy losses along the electrode has a single solution and can be used directly to correct the excitation signal of the respective crossing point.

[0091] The advantage of the second approach over the first is that it does not result in a summation of the currents at the reference electrode. Assuming that all non-excited transmitting wires are completely grounded and thus make no contribution to the measured signal at the reference electrode, the first approach would be sufficient. However, with high conductivities and long wires, a non-negligible voltage input to non-excited transmitting wires also occurs, which can be accurately determined using the second approach. However, the second approach involves increased circuit complexity.

[0092] According to various aspects, a grid sensor is provided that is suitable for determining phase distributions in multiphase fluid flows. In particular, in fluid flows with electrically (highly) conductive phase components, e.g., for the investigation of multiphase flows in the petroleum industry. With conventional capacitive grid sensors, measurement deviations can occur in the presence of electrically conductive phases, for example, in the form of nonlinearities. This can cause signal losses at the receiving electrodes due to energy dissipation. The signal losses can depend on the respective wetting of the individual electrodes and / or sensor elements with the conductive phase and thus vary during the measurement process.

[0093] The exemplary configurations of grid sensors and the methods described above can make it possible to quantify and thus correct signal losses. This can improve the accuracy and significance of a measurement using the grid sensor. In particular, quantification of phase components can be enabled even in the presence of electrically (highly) conductive phases.

Claims

1. A grid sensor comprising: a fluid guiding area (130); multiple grid sensor units, wherein each of the multiple grid sensor units comprises: a group of sensor elements (120) configured to generate measurement signals representing one or more properties of a fluid guided in the fluid guiding area (130); an electrode (110), wherein the sensor elements of the group of sensor elements (120) are connected to the electrode (110) for operating the sensor elements of the group of sensor elements (120); characterized in that each of the multiple grid sensor units comprises: a reference element (140) associated with the electrode (110), connected to the electrode (110) and configured to provide a reference signal representing a disturbance influence of the fluid guided in the fluid guiding area (130) on an electrical characteristic of the electrode.

2. The grid sensor according to claim 1, wherein the one or more properties of the fluid may comprise one or more of the following properties: an electrical conductivity, and / or a temperature, and / or a pressure.

3. The grid sensor according to claim 1 or 2, wherein the sensor elements of the group of sensor elements (120) comprise one or more temperature sensors, and / or one or more voltage sensors, and / or one or more pressure sensors, and / or one or more current sensors, and / or one or more inductance sensors, and / or one or more capacitance sensors, and / or one or more magnetic field strength sensors, and / or one or more light intensity sensors.

4. The grid sensor according to any one of claims 1 to 3, wherein the reference signal represents one or more of the following values: a reference temperature, and / or a reference voltage, and / or a reference pressure, and / or a reference current strength, and / or a reference inductance, and / or a reference capacitance, and / or a reference magnetic field strength, and / or a reference luminous intensity, and / or a reference resistance.

5. The grid sensor according to any one of claims 1 to 4, wherein the reference element (140) is arranged and / or configured such that a predefined output signal is output by the reference element (140), wherein the predefined output signal is independent of a fluid guided in the fluid guiding area (130), and wherein the reference signal is the predefined output signal as modified due to the interference of the fluid guided in the fluid guiding area (130) on an electrical characteristic of the electrode.

6. The grid sensor according to claim 5, wherein the reference element (140) is arranged outside the fluid guiding region (130) for avoiding an influence of the fluid guided in the fluid guiding region (130) on the predefined output signal output by the reference element (140).

7. The grid sensor according to any one of claims 1 to 6, wherein the reference element (140) is shielded from a fluid guided in the fluid guiding area (130) by a shield.

8. The grid sensor according to any one of claims 1 to 7, wherein the grid sensor is configured such that the reference signal corresponds to a predefined output signal of the reference element (140) if there is no interference of the fluid on the electrical characteristic of the electrode (110), and that the reference signal corresponds to a superposition of the predefined output signal of the reference element (110) with one or more interference signals if one or more interference influences on the electrical characteristics of the electrode (110) are present.

9. A grid sensor system, a grid sensor according to any one of claims 1 to 8, a determination device configured to determine the reference signal and to determine the measurement signals, and wherein a measurement signal of the measurement signals is associated with a sensor element of the group of sensor elements (120), respectively.

10. The grid sensor system according to claim 9, wherein the determination device is configured to determine a calibration value in a calibration measurement based on the reference signal, wherein the calibration value represents a state of the grid sensor in which a first fluid completely fills the fluid guiding area (130) of the grid sensor.

11. The grid sensor system according to claim 10, wherein the determination device is configured to determine, in a first measurement, a first reference value based on the reference signal and first measurement values based on the measurement signals, wherein the first reference value and the first measurement values represent a state of the grid sensor in which at least a second fluid in addition to the first fluid is present in the fluid guiding region (130) of the grid sensor, and wherein the first fluid and the second fluid differ from each other in at least one of the one or more properties by more than 1%.

12. The grid sensor system according to claim 10, wherein the determination device is configured to determine, in a first measurement, a first reference value based on the reference signal and first measurement values based on the measurement signals, wherein the first reference value and the first measurement values represent a state of the grid sensor in which a second fluid completely fills the fluid guiding area (130) of the grid sensor, wherein the first fluid and the second fluid differ from each other in at least one of the one or more properties by more than 1%.

13. The grid sensor system according to any one of claims 11 to 12, further comprising: a calculating device configured to calculate a correction value for correcting the disturbance influence based on the calibration value and the first reference value, and to calculate corrected first measurement values based on the first measurement values and the correction value.

14. A method for evaluating measurement data, the method comprising: receiving measurement data and reference data from a grid sensor according to any one of claims 1 to 8, wherein the grid sensor has been at least partially flowed around by one or more fluids, wherein the measurement data represent at least one property of the one or more fluids and exhibits an interference influence of the one or more fluids on the grid sensor, and wherein the reference data represent the interference of the one or more fluids on the grid sensor; performing a measurement value correction to create corrected measurement data based on the measurement data and the reference data, wherein the measurement value correction corrects the interference of the one or more fluids on the grid sensor; and outputting the corrected measurement data representing at least one property of the one or more fluids and independent of the interference of the one or more fluids on the grid sensor.

15. A computer program product comprising instructions for causing one or more processors to perform the method of claim 14.