Measuring device for contactlessly determining an electrical variable of a current-carrying conductor, and method for contactlessly determining an electrical variable

Abstract

The invention relates to a measuring device (10) for contactlessly determining an electrical variable of a current-carrying conductor (12), the measuring device comprising at least one first sensor element (14), wherein the measuring device (10) has at least one second sensor element (16), and the first sensor element (14) and the second sensor element (16) are at a predefined distance (ds) from one another relative to a measurement region (18) of the measuring device (10) for the conductor (12). The invention also relates to a method.

Description

[0001] Description

[0002] Measuring device for the contactless determination of an electrical quantity of a current-carrying conductor and method for the contactless determination of an electrical quantity

[0003] The invention relates to a measuring device for the contactless determination of an electrical quantity of a current-carrying conductor, comprising at least one first sensor element. Furthermore, the invention relates to a corresponding method for the contactless determination of an electrical quantity of a current-carrying conductor using a measuring device.

[0004] The problem of cost-effective, precise, and easy-to-perform, non-contact energy flow measurement for an electrical conductor is already known from the state of the art. To measure the energy flow, two different sensors are used to determine the current flow and the voltage of the conductor. For the current flow, the magnetic field is measured using a Hall sensor, GMR, GTR, Rogowski coil, or similar sensor, and the electric field of the conductor can be used for the voltage measurement. One requirement for the sensor is to enable energy measurement that is as simple to set up and user-friendly as possible. Since a multitude of interfering variables affect both measured variables, technical measures must be taken to minimize their influence.An example of these variable disturbances is that in both measured quantities, especially the E-field and the B-field, the distance to the conductor being measured is directly reflected in the measurement signal. However, other effects, such as the geometric alignment of the conductor relative to the sensors or interference fields, also lead to erroneous, imprecise measurements. External disturbances caused by external E- and B-fields will not be discussed further here, as it is assumed that the measuring device in question is appropriately shielded.

[0005] Current energy measurements are performed using a device that is inserted into the existing power connection, particularly the line, for example in the form of a cable. This is necessary because accurate voltage measurement requires electrical and ohmic contact with the live conductor. The measurement itself is then performed, for example, using analog-to-digital converters. Non-contact measurement methods such as the Hall sensor or Rogowski coils, as already mentioned, are known for measuring current flow. Furthermore, non-contact measurements of energy flows using a non-contact energy meter, also known as an electric field mill, are now known from the current state of the art.

[0006] To reduce the influence of the difficult and noticeable distance between the sensor and the measuring object, currently available methods include fixed mechanical stops or distance measurement using additional tools, such as calipers or optical sensors. The resulting distance can then be used to calibrate the measurement signal.

[0007] However, this solution presents problems with regard to accuracy and long-term performance. On the one hand, the distance must either be precisely known for each measurement, or it must not vary over the applied operating time.

[0008] Even small changes in distance can result in large deviations in measurement quality, and small ohmic contact changes in voltage measurements can also lead to measurement inaccuracies.

[0009] In addition, for electrical contact, especially for voltage measurement, it is currently necessary to disconnect the device to be measured from the power supply, or a specially trained worker must install the measuring device while the device is live, which can be particularly life-threatening.

[0010] The object of the present invention is to provide a measuring device and a method by means of which an improved contactless measurement of an electrical quantity of a current-carrying conductor can be determined.

[0011] This object is achieved by a measuring device and a method according to the independent patent claims. Advantageous embodiments are specified in the subclaims.

[0012] One aspect of the invention relates to a measuring device for the contactless determination of an electrical quantity of a current-carrying conductor, comprising at least one first sensor element. The measuring device comprises at least one second sensor element, wherein the first sensor element and the second sensor element are spaced apart by a predetermined distance relative to a measuring range of the measuring device for the conductor.

[0013] In other words, the first sensor element and the second sensor element are spaced apart by a predetermined distance. In particular, the distance is selected such that this distance is relative to the measuring range, for example, in which a current-carrying conductor can be arranged. For example, the two sensor elements can then be aligned substantially parallel to the current-carrying conductor to be measured, but at a corresponding distance from each other.

[0014] This allows position-dependent interference to be minimized, particularly in the corresponding sensor conductors.

[0015] In particular, the invention solves the problem described above by combining two or more sensor elements per sensor cell at a fixed distance and orientation relative to one another. This intrinsically fixed arrangement enables a self-calibrating calculation of the distance between the sensor element and the measurement object and thus a correction / calibration of the measurement signal. Alternatively, the resulting differential signal can also be used to perform a distance-independent measurement. The principle of this invention can be applied separately to both sensor types, in particular voltage measurement and current measurement, or to just one or each of the two sensor elements.

[0016] For example, if we assume a constant and homogeneous electric field E near the conductor, the height of the electric field is: with the voltage U and the distance of the sensor element to the conductor d x . And with the distance ds between the two sensor elements precisely defined by the sensor assembly technology:

[0017] After rearranging and solving this formula, the voltage U is:

[0018] Thus, regardless of the respective sensors to the conductor, the voltage can be reliably determined based solely on the distance between the sensors.

[0019] In contrast to a measuring device with only a single sensor element, the different spatial arrangement and orientation of the sensor elements allows position-dependent disturbances and influences to be eliminated or optimized for user-friendliness. This results in greater measurement precision. Furthermore, greater error tolerance in positioning and easier installation can be achieved. Furthermore, attaching the sensor to existing electrical lines can be simplified, and self-calibration of the sensor is enabled. Therefore, in particular, fewer trained service personnel are required to supply an existing production facility with energy measuring points, thus achieving cost savings for service technicians, for example.

[0020] In this case, contactless can also be understood as contactless.

[0021] According to an advantageous embodiment, the measuring device is designed to detect a first electric field at the first sensor element of the current-carrying conductor and to detect a second electric field at the second sensor element of the current-carrying conductor. In particular, the respective sensor elements then detect different electric fields. Based on these electric fields, the distance between the sensor elements can then be used to reliably determine, for example, the voltage within the current-carrying conductor.

[0022] In a further advantageous embodiment, the measuring device comprises an electronic computing device, and the electronic computing device is configured to determine a voltage as an electrical quantity based on the first electric field, the second electric field, and the distance. Thus, the voltage within the current-carrying conductor can be determined simply and reliably.

[0023] A further advantageous embodiment provides that the measuring device is designed to detect a first magnetic field at the first sensor element of the current-carrying conductor and to detect a second magnetic field at the second sensor element of the current-carrying conductor. Thus, magnetic fields can also be detected by the measuring device. Based on the magnetic field, in particular, the current within the current-carrying conductor can be deduced.

[0024] A further advantageous embodiment provides that the measuring device has an electronic computing device, and the electronic computing device is configured to determine a current as an electrical quantity based on the first magnetic field, the second magnetic field, and the distance. Thus, the current can be reliably determined based on the magnetic fields and the distance from one another.

[0025] A further advantageous embodiment provides that a second detection surface of the second sensor element is tilted relative to a first detection surface of the first sensor element. In particular, the signal quality for the case of a tilted electrical conductor can thus be achieved by deliberately arranging sensor elements at different inclinations, but in particular with a known tilt. In particular, with a vector representation, it is then again clear that, for example, if one of the sensor elements is tilted, a full E-field of the conductor can be detected, whereas at other sensor elements only the smaller, for example vertical, component of the E-field occurs. If the sensor elements are tilted accordingly, conclusions can be drawn about the actual orientation of the current-carrying conductor relative to the sensor elements.

[0026] It is also advantageous if the geometry of at least two sensor elements is adapted to the geometry of the conductor. In particular, this allows the sensor elements to be optimized accordingly to the geometry of the cable. This means, for example, that a cable measurement is more likely to be defined using cylindrical geometries, while a circuit board and / or busbar application is more likely to be defined using Cartesian geometries. From a technical perspective, this covers all possible spatial deviations between the sensor elements and the cable guide, so that at least one X, Y, or Z axis, or one Z, r, or phi, is covered.

[0027] It is also advantageous if the measuring device has at least a third sensor element and / or a fourth sensor element. The four sensor elements allow for even more precise determination of the electrical quantity. In particular, tilting in different spatial directions can be achieved, for example, by tilting the corresponding sensor elements relative to each other. This minimizes the corresponding interference, allowing for improved measurement or determination of the electrical quantity.

[0028] It is also advantageous if at least the third sensor element or the fourth sensor element is tilted relative to the first sensor element and / or the second sensor element. This allows the different spatial directions and thus the different interference influences to be eliminated when the conductor is tilted accordingly relative to the measuring device.

[0029] It has also proven advantageous if the first sensor element and the second sensor element are arranged on a common circuit board. This allows for a simple arrangement or design of the sensor elements and thus of the measuring device. The circuit board then serves, in particular, to electrically contact the sensor elements.

[0030] A further advantageous embodiment provides that the first sensor element is arranged on a first side of the circuit board, and the second sensor element is arranged on a second side of the circuit board opposite the first side. This allows a distance between the first sensor element and the second sensor element to be automatically adjusted. In particular, the distance is then defined, for example, by the thickness of the circuit board. This allows a predefined distance between the two sensor elements to be easily realized, allowing the electrical quantity to be reliably determined.

[0031] It is also advantageous if the first sensor element and the second sensor element are arranged stacked on top of one another. For example, the first sensor element can be stacked on top of the second sensor element. In particular, the second sensor element is thus arranged closer to the measuring area than the first sensor element. Stacking allows a fixed distance to be achieved between the two sensor elements, which enables reliable determination of the electrical quantity.

[0032] It has also proven advantageous if at least one of the sensor elements is designed as a microelectromechanical system. In particular, this is an MEM / EMS component. In particular, the measuring device is then provided essentially as an electric field mill. This allows for contactless measurement of the electrical quantity.

[0033] A further aspect of the invention relates to a method for the contactless determination of an electrical quantity of a current-carrying conductor using a measuring device according to the preceding aspect. A first field of the conductor is detected by the first sensor element. A second field of the conductor is detected by the second sensor element. The electrical quantity is determined as a function of the first field, the second field, and the distance between the first sensor element and a second sensor element using an electronic computing device of the measuring device.

[0034] Advantageous embodiments of the measuring device are considered advantageous embodiments of the method. The measuring device, in particular, has specific features enabling the corresponding method steps to be carried out.

[0035] A computing unit / electronic computing device can be understood, in particular, as a data processing device that contains a processing circuit. The computing unit can therefore, in particular, process data to perform computing operations. This may also include operations for performing indexed access to a data structure, for example, a look-up table (LUT), or function descriptions as formulas.

[0036] The computing unit may, in particular, contain one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more single-chip systems (SoCs). The computing unit may also contain one or more processors, for example, one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, in particular one or more digital signal processors (DSPs). The computing unit may also include a physical or virtual network of computers or other of the aforementioned units.

[0037] In various embodiments, the computing unit includes one or more hardware and / or software interfaces and / or one or more memory units.

[0038] A memory unit can be a volatile data memory, for example a dynamic random access memory (DRAM) or a static random access memory (SRAM), or a non-volatile data memory, for example a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory or flash EEPROM, a ferroelectric random access memory (FRAM), a magnetoresistive random access memory,MRAM (magnetoresistive random access memory) or phase-change random access memory (PCRAM).

[0039] For applications or application situations that may arise in a method according to the invention and which are not explicitly described herein, it may be provided that, according to the method, an error message and / or a request to enter user feedback is output and / or a standard setting and / or a predetermined initial state is set.

[0040] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0041] Further features and combinations of features of the invention will become apparent from the figures and their description, as well as from the claims. In particular, further embodiments of the invention do not necessarily have to contain all features of one of the claims. Further embodiments of the invention may have features or combinations of features not mentioned in the claims.

[0042] Showing:

[0043] FIG 1 shows a schematic view of an embodiment of a measuring device;

[0044] FIG 2 shows a further schematic view of an embodiment of a

[0045] measuring device;

[0046] FIG 3 to FIG 5 further schematic views of a further embodiment of the

[0047] Measuring device in different perspective views;

[0048] FIG 6 shows a further schematic view of an embodiment of a

[0049] measuring device;

[0050] FIG 7 is yet another schematic view of an embodiment of a

[0051] measuring device;

[0052] FIG 8 is yet another schematic view of an embodiment of a

[0053] measuring device;

[0054] FIG 9 is yet another schematic view of an embodiment of a

[0055] measuring device; and

[0056] FIG 10 is yet another schematic view of an embodiment of a

[0057] measuring device.

[0058] The invention is explained in more detail below using specific embodiments and associated schematic drawings. In the figures, identical or functionally equivalent elements may be provided with the same reference numerals. The description of identical or functionally equivalent elements may not necessarily be repeated for different figures.

[0059] FIG 1 shows a schematic view of an embodiment of a measuring device 10.

[0060] The measuring device 10 is designed for the contactless determination of an electrical quantity E, B of a current-carrying conductor 12. For this purpose, the measuring device 10 has at least one first sensor element 14. FIG. 1 further shows that the measuring device 10 has at least one second sensor element 16, wherein the first sensor element 14 and the second sensor element 16 are spaced apart by a predetermined distance d s to each other relative to a measuring range 18 of the measuring device 10 for the conductor 12.

[0061] In particular, FIG. 1 shows that the measuring device 10 is designed to detect an electric field Ei at the first sensor element 14 of the current-carrying conductor 12 and to detect a second electric field E2 at the second sensor element 16 of the current-carrying conductor 12. It can further be provided that the measuring device 10 has at least one electronic computing device 20, and the electronic computing device 20 is designed to, on the basis of the first electric field Ei, the second electric field E2 and the distance d s to determine a voltage as an electrical quantity.

[0062] Alternatively, it can be provided that the measuring device 10 is designed to detect a first magnetic field B at the first sensor element 14 of the current-carrying conductor 12 and to detect a second magnetic field B at a second sensor element 16 of the current-carrying conductor 12. The magnetic field B is identified below by way of example with the letter B. For this purpose, it can further be provided that the measuring device 10 also uses the electronic computing device 20 to determine, on the basis of the first magnetic field B, the second magnetic field B and the distance d s to determine a current as an electrical quantity.

[0063] In particular, the invention solves the problem by arranging two or more sensor elements 14, 16, 22, 24 (FIG. 8) per sensor cell at a fixed distance d sand alignment to one another. This intrinsically fixed arrangement enables a self-calibrating calculation of the distance between the measuring device 10 and the conductor 12 and thus a correction / calibration of the measurement signal. Alternatively, the resulting difference signal can also be used to perform a distance-independent measurement. The principle of this invention can be applied separately to both sensor types, in particular the voltage measurement based on the electric field E and the current measurement based on the magnetic field B, or only to one or each of the two sensor elements 14, 16, 22, 24. FIG. 2 shows a further schematic view of an embodiment of a measuring device 10. In the present exemplary embodiment, it is shown in particular that a second detection surface 34 of the second sensor element 16 is tilted relative to a first detection surface 32 of the first sensor element 14.In particular, to further increase accuracy, more than two or more sensors can be combined, with the sensor elements 14, 16 being aligned in particular in different spatial directions. The spatial directions and the sensor orientations are optimized according to the geometry of the conductor 12. This means that a cable measurement is defined with a cylindrical geometry, while a circuit board and / or busbar application is preferred with Cartesian geometries.

[0064] If we now assume approximately a constant and homogeneous electric field E in the vicinity of the conductor 12, the height of the electric field E is: with the voltage U and the distance of the sensor element 14, 16, 22, 24 to the conductor 12 d x . And with the distance d precisely defined by sensor construction technology s between the two sensor elements 14, 16, 22, 24:

[0065] After rearranging and solving this formula, the voltage U is:

[0066] Thus, regardless of the respective sensors to the conductor 12, the voltage can be reliably determined based solely on the distance between the sensors.

[0067] FIG. 2 shows a further improvement in signal quality for the case of a tilted electrical conductor 12, whereby sensor elements 14, 16 deliberately arranged at different inclinations are used. From the vectorial representation, as shown in FIG. 2, it is clear that the second sensor element 16 experiences the full electric field of the conductor 12, whereas only the smaller, vertical component of the electric field is present in the first sensor element 14. If the sensor elements 14, 16 are tilted in both spatial directions, the actual orientation of the current-carrying conductor 12 relative to the sensor elements 14, 16 can be deduced.

[0068] Figures FIG 3 to FIG 5 again show the current-carrying conductor 12 and the measuring device 10, with different views of the measuring device 10 being shown in figures FIG 3 to FIG 5. For example, FIG 3 shows a section through the conductor 12, FIG 4 shows a side view of the conductor 12 and the measuring device 10, and FIG 5 shows the conductor 12 with the measuring device 10 located behind it. In the present case, it is shown in particular that the second sensor element 16 is tilted relative to the first sensor element 14 and the second sensor element 16 is not tilted in the present plane.

[0069] A third sensor element 22 is shown thicker and thus tilted in the plane. A fourth sensor element 24 is also shown, which is also tilted.

[0070] FIG 4 shows the corresponding representation from FIG 3 in a different perspective.

[0071] FIG. 5 again shows the measuring device 10 according to FIG. 3 and FIG. 4 in a further view, wherein in this view the conductor 12 lies in front of the corresponding sensor elements 14, 16, 22, 24.

[0072] In particular, it is intended that the number of sensor elements 14, 16, 22, 24 is not limited to four. The number of sensor elements may be limited solely based on space availability.

[0073] As already mentioned, only the E fields are shown in the figures, although the same procedure is also conceivable for B fields. Furthermore, it can be provided that the first sensor element 14 and the second sensor element 16 are arranged on a common circuit board 30. The sensor elements 14, 18, 22, 24 are designed, in particular, as a microelectromechanical system (MEMS).

[0074] FIG. 6 shows a further schematic view of an embodiment of a measuring device 10. In particular, it is shown that the first sensor element 14 is formed on a first circuit board 26 and the second sensor element 16 is formed on a second circuit board 28. As an alternative to the circuit board 26, a substrate, in particular a chip substrate, can also be used. Furthermore, the first sensor element 14 is oriented in the direction of the conductor 12, and the second sensor element 16 is oriented at a 90-degree angle to the conductor 12. The sensor elements 14, 16 can in particular be designed essentially identically, wherein the corresponding alignment in the package is then decisive in order to form a further sensor element with a defined distance. For example, as shown in FIG. 6, a rotation of 90 degrees can be represented.

[0075] Another possibility is shown in FIG. 7, in which the sensor elements 14, 16 are rotated by 180 degrees, which can also be referred to as a flip-chip. In particular, the distance variance in the pm range can then be defined based on the sensor thickness, which is usually made of silicon or another substrate commonly used in semiconductor technology.

[0076] FIG. 8 shows a further embodiment of the measuring device 10. In particular, it is shown that the first sensor element 14 and the second sensor element 16 can be formed on a common circuit board 30 or substrate. In particular, the third sensor element 22 can also be arranged on the common circuit board 30, in this case tilted relative to the conductor 12. In particular, FIG. 8 thus shows that deposition or manufacturing on an inclined plane, such as crystal structures of 54.7 degrees or 35.3 degrees, can also be realized. Thus, a position variance can also be realized.

[0077] FIG. 9 shows, in particular, that the sensor elements 14, 16 can also be stacked, thus forming a so-called stack. In particular, the sensor elements 14, 16 are mounted directly one above the other, with the defined spacing then being defined by the thickness of the first circuit board 26.

[0078] FIG. 10 shows a further embodiment in which the sensor elements 14, 16 can be arranged on circuit boards 26, 28 of different thicknesses. This allows the corresponding spacings to be defined, for example, via the spacing geometries of the circuit boards 26, 28.

[0079] In particular, the structural arrangement of the semiconductors or the

[0080] Sensor elements 14, 16, 22, 24 can be connected in different ways. This can be done, in particular, on the same wafer or on the same circuit board 30, on the top and bottom sides of the circuit board 30, by stacking several semiconductors at the wafer level, for example, wafer bonding, within the sensor package, for example, side by side, at the sensor housing level, i.e., within the sensor device, or by arranging several individual sensor housings side by side.

[0081] A corresponding evaluation or self-calibration of the sensor elements 14, 16, 22, and 24 can be performed using software-based standard or AI-based algorithms. The latter is particularly useful when not only inaccuracies due to spatial positioning need to be corrected, but also interference from magnetic, electrical, or high-frequency fields needs to be considered and corrected. As an example, consider a third three-phase power cable. In this cable, the complex spatial arrangement is also subject to mutual interference between the phases.

[0082] A sensor element 14, 16, 22, 24 can also be manufactured from several layers, with each layer corresponding to its own sensor element and thus intrinsically forming a new sensor element 14, 16, 22, 24 through the layer variance and layer thickness.

[0083] Furthermore, the measuring device 10 can also be expanded by additional sensors / sensor technology, such as temperature sensors, humidity sensors, pressure sensors, force sensors, position sensors, light sensors, gas sensors or sound sensors.

[0084] List of reference symbols

[0085] 10 Measuring device

[0086] 12 ladders

[0087] 14 first sensor element

[0088] 16 second sensor element

[0089] 18 measuring range

[0090] 20 electronic computing devices

[0091] 22 third sensor element

[0092] 24 fourth sensor element

[0093] 26 first circuit board

[0094] 28 second circuit board

[0095] 30 common circuit board

[0096] 32 first detection area

[0097] 34 second detection area E electric field B magnetic field

[0098] The first electric field

[0099] E2second electric field DI first distance D2second distance

Claims

Patent claims 1. Measuring device (10) for the contactless determination of an electrical variable of a current-carrying conductor (12), with at least one first sensor element (14), characterized in that the measuring device (10) has at least one second sensor element (16), wherein the first sensor element (14) and the second sensor element (16) have a predetermined distance (ds) from one another relative to a measuring range (18) of the measuring device (10) for the conductor (12).

2. Measuring device (10) according to claim 1, characterized in that the measuring device (10) is designed to detect a first electric field (Ei) at the first sensor element (14) of the current-carrying conductor (12) and to detect a second electric field (E2) at the second sensor element (16) of the current-carrying conductor (12).

3. Measuring device (10) according to claim 2, characterized in that the measuring device (10) has an electronic computing device (20) and the electronic computing device (20) is designed to calculate, on the basis of the first electric field (Ei), the second electric field (E2) and the distance (d s ) to determine a voltage as an electrical quantity.

4. Measuring device (10) according to claim 1, characterized in that the measuring device (10) is designed to detect a first magnetic field (B) at the first sensor element (14) of the current-carrying conductor (12) and to detect a second magnetic field (B) at the second sensor element (16) of the current-carrying conductor (12).

5. Measuring device (10) according to claim 4, characterized in that the measuring device (10) has an electronic computing device (20) and the electronic computing device (20) is designed to determine a current as an electrical quantity on the basis of the first magnetic field (B), the second magnetic field (B) and the distance (ds).

6. Measuring device (10) according to one of the preceding claims, characterized in that a second detection surface (34) of the second sensor element (16) is tilted relative to a first detection surface (32) of the first sensor element (14).

7. Measuring device (10) according to one of the preceding claims, characterized in that a geometry of the at least two sensor elements (14, 16, 22, 24) is adapted to a geometry of the conductor (12).

8. Measuring device (10) according to one of the preceding claims, characterized in that the measuring device (10) has at least a third sensor element (22) and / or a fourth sensor element (26).

9. Measuring device (10) according to claim 8, characterized in that at least the third sensor element (22) and / or the fourth sensor element (24) is tilted relative to the first sensor element (14) and / or the second sensor element (16).

10. Measuring device (10) according to one of the preceding claims, characterized in that the first sensor element (14) and the second sensor element (16) are arranged on a common printed circuit board (30).

11. Measuring device (10) according to claim 10, characterized in that the first sensor element (14) is arranged on a first side of the circuit board (30) and the second sensor element (16) is arranged on a second side (30) opposite the first side.

12. Measuring device (10) according to one of the preceding claims, characterized in that the first sensor element (14) and the second sensor element (16) are arranged stacked on top of one another.

13. Measuring device (10) according to one of the preceding claims, characterized in that the first sensor element (14) and the second sensor element (16) are arranged next to one another.

14. Measuring device (10) according to one of the preceding claims, characterized in that at least one of the sensor elements (14) is designed as a microelectromechanical system.

15. Method for contactless determination of an electrical quantity of a current-carrying conductor (12) by means of a measuring device (10) according to one of the claims 1 to 14, comprising the steps of: - detecting a first field (E, B) of the conductor (12) by means of the first sensor element (14); - detecting a second field (E, B) of the conductor (12) by means of the second sensor element (16); and - Determining the electrical quantity as a function of the first field (E, B), the second field (E, B) and the distance (ds) between the first sensor element (14) and the second sensor element (16) by means of an electronic computing device (20) of the measuring device (10).

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