Method for determining magnetization direction of wiegand filament and wiegand sensor device

Abstract

The invention relates to a method for determining a magnetization direction (M) of a wiegand (11), in which a test current (Ip) rising over time (t) is fed into a sensor coil (12) surrounding the wiegand (11), a sensor coil voltage (US) present on the sensor coil (12) is detected during the feeding of the test current (Ip), and determining the magnetization direction (M) by comparing the sensor coil voltage (US) detected during the feed-in of the test current with a reference voltage (UR) which increases simultaneously with the test current (Ip), wherein the reference voltage increases from a defined starting point reference voltage value (URa) to a defined end point reference voltage value (URe). The invention also relates to a Wiegand sensor device (100) comprising a Wiegand (11) and a sensor coil (12) surrounding the Wiegand (11), in which there is a magnetization direction determination unit (3) arranged to carry out the method according to the invention for determining the magnetization direction (M) of the Wiegand (11).

Description

Technical Field

[0001] The present invention relates to a method for determining the magnetization direction of a Wiegand wire, wherein: a test current increasing with time is fed into a sensor coil surrounding the Wiegand wire, and a sensor coil voltage present on the sensor coil is detected during the feeding of the test current. The present invention also relates to a Wiegand sensor device, which includes: a Wiegand wire and a sensor coil surrounding the Wiegand wire. Background Art

[0002] The Wiegand wire in the context of the present application is also referred to as a pulse wire and generally has a hard magnetic outer shell and a soft magnetic inner core, or a soft magnetic sheath and a hard magnetic core. Under the action of an external magnetic field, the magnetization direction of the Wiegand wire suddenly reverses, thereby generating a short Wiegand voltage pulse in a sensor coil that radially surrounds the Wiegand wire. The Wiegand voltage pulse can be measured via both ends of the sensor. This effect is called the Wiegand effect and is well known in the prior art.

[0003] Knowing the magnetization direction of the Wiegand wire is important, for example, in a rotary encoder, to synchronize between a tachometer sensor unit based on a Wiegand sensor (also known as a multi-turn sensor unit) and a precise position sensor unit (also known as a single-turn sensor unit).

[0004] In this context, a method for determining the magnetization direction of a Wiegand wire is known from EP1565755B1, wherein a rising test current is fed into a sensor coil surrounding the Wiegand wire and the sensor coil voltage present on the sensor coil is detected and analyzed during the feeding of the test current. Summary of the Invention

[0005] The object of the present invention is to enable a relatively simple and reliable determination of the magnetization direction of a Wiegand wire.

[0006] This object is achieved by a method for determining the magnetization direction of a Wiegand wire having the features of claim 1.

[0007] In the method for determining the magnetization direction of a Wiegand wire according to the present invention, a test current rising with time is fed into a sensor coil surrounding the Wiegand wire to generate a test magnetic field acting on the Wiegand wire. Preferably, it is provided that the test current continuously starts from zero, i.e., always rises in a manner following a defined test current curve. Particularly preferably, it is provided that the test current rises linearly with a defined slope. The curve of the test current can be defined, for example, based on the results of laboratory tests. It is also conceivable to define different test current curves for different measurement conditions, such as for different temperatures.

[0008] If the magnetization direction is reversed due to the generated test magnetic field, the wire will induce a so-called Wiedemann voltage pulse into the sensor coil. Whether a Wiedemann voltage pulse appears or not can be used to determine whether the magnetization direction of the wire is in the same or opposite direction relative to the test magnetic field before the test current is fed in.

[0009] Therefore, in the method for determining the magnetization direction of the wire according to the present invention, the sensor coil voltage on the sensor coil is detected and analyzed during the feeding of the test current.

[0010] In order to determine whether a Wiedemann voltage pulse has been induced in the sensor coil and thereby determine the magnetization direction of the wire, according to the present invention, the sensor coil voltage detected during the feeding of the test current is compared with a reference voltage that simultaneously and preferably rises with the test current in the same shape, and the reference voltage rises from a defined starting reference voltage value to a defined ending reference voltage value. The starting reference voltage value and the ending reference voltage value can be defined directly here, or indirectly, for example, by a given mathematical relationship. Preferably, it is stipulated that the reference voltage increases continuously, and particularly preferably, the reference voltage increases linearly. Here, for example, it can be envisaged that the ending reference voltage value is defined indirectly by a given reference voltage slope. The comparison of the sensor coil voltage with the reference voltage is preferably implemented by means of corresponding hardware, such as a comparator, which compares the sensor coil voltage detected on the sensor coil with the reference voltage signal that rises simultaneously with the measurement current. However, the comparison of the sensor coil voltage with the reference voltage can in principle also be implemented in software, where a sensor coil voltage variable reflecting the detected sensor coil voltage is compared with a reference voltage variable that rises simultaneously with the measurement current.

[0011] The magnetization direction is determined here according to whether the voltage of the sensor coil exceeds a reference voltage during the feeding of a measurement current, i.e., according to whether the value is greater than the reference voltage. If the voltage of the sensor coil exceeds the reference voltage, it is considered that a Wiedemann voltage pulse has been induced and thus the Wiedemann wire already had a magnetization direction opposite to the direction of the test magnetic field before the test current was fed. In this case, the magnetization direction is determined as a first magnetization direction value. Conversely, if the voltage of the sensor coil does not exceed the reference voltage, it is considered that no Wiedemann voltage pulse has been induced and thus the Wiedemann wire already had a magnetization direction the same as the direction of the test magnetic field before the test current was fed. In this case, the magnetization direction is determined as a second magnetization direction value. In order to avoid misjudging the magnetization direction due to voltage fluctuations, a determined minimum exceed duration can be advantageously set as the criterion for judging the exceed, i.e., only when the voltage of the sensor coil exceeds the reference voltage for the minimum exceed duration, the magnetization voltage is determined as the first magnetization direction value. The determined magnetization direction value is generally stored in a data memory. However, it is also conceivable not to store the magnetization direction value but only to process it. For example, the number-of-turns count value can be determined or corrected based on the determined magnetization direction value.

[0012] The method according to the invention can thus simply and reliably determine the magnetization direction of the Wiedemann wire.

[0013] The electrical characteristics of the sensor coil, in particular the resistance of the sensor coil, are generally temperature-dependent, so that the voltage drop across the sensor coil caused by feeding the test current is also temperature-dependent according to Ohm's law. Therefore, preferably, the temperature is detected in the method according to the invention and the starting reference voltage value and / or the ending reference voltage value are defined based on the detected temperature, so that the magnetization direction of the Wiedemann wire can be reliably determined in a manner independent of the current temperature.

[0014] In a preferred embodiment of the method according to the invention, calibration is performed before feeding the test current. Here, a calibration current that preferably rises with time is fed into the sensor coil, the calibration current having a maximum calibration current value that is 1 / N of the maximum test current value of the test current, and the voltage of the sensor coil is detected during the feeding of the calibration current. The ending reference voltage value to which the reference voltage finally rises is then defined as the sum of the starting reference voltage value and N times the maximum sensor coil voltage value detected during the feeding of the calibration current. The ending reference voltage value thus always exceeds the maximum voltage drop across the sensor coil caused by the test current, so that it is possible to reliably avoid the reference voltage being exceeded due to the voltage of the sensor coil caused only by the test current under conditions independent of the current measurement conditions.

[0015] Preferably, the sensor coil voltage detected during the feeding of the calibration current is compared with a constant calibration reference voltage value which is greater than (preferably only slightly greater than) the product of the maximum calibration current value and the resistance of the sensor coil, in order to determine whether a Wiedemann voltage pulse is induced in the sensor coil during calibration. If the sensor coil voltage detected during the feeding of the calibration current exceeds the calibration reference voltage value, it is determined that a Wiedemann voltage pulse has been induced and thus the magnetization direction is determined as the first magnetization direction value. In order to avoid an incorrect determination of the magnetization direction due to voltage fluctuations, it may also be advantageous here to set a determined minimum over-duration as the criterion for the determination of the overshoot. In order to avoid so-called distortion pulses (Krüppelpuls) after calibration, although the magnetization direction is already known, it is preferably still the case that a test current is fed into the sensor coil in order to magnetize the Wiedemann wire completely.

[0016] The above object is also achieved by a Wiedemann sensor device having the features of claim 5.

[0017] The Wiedemann sensor device according to the invention comprises a Wiedemann wire and a sensor coil which radially surrounds the Wiedemann wire. This arrangement of the Wiedemann wire and the sensor is well known in the prior art and is also referred to as a Wiedemann sensor.

[0018] According to the invention, the Wiedemann sensor device comprises a magnetization direction determination unit which is electrically connected to the sensor coil and is arranged to carry out the method according to the invention for determining the magnetization direction of the Wiedemann wire.

[0019] In particular, the magnetization direction determination unit is arranged to feed a test current rising with time into the sensor coil and to detect the sensor coil voltage present on the sensor coil during this time. For this purpose, the magnetization direction determination unit generally comprises an adjustable current source configured in any known manner and a voltage measuring device configured in any known manner.

[0020] Furthermore, the magnetization direction determination unit is arranged to determine the magnetization direction of the Wiedemann wire, as has been described for the method according to the invention, by comparing the sensor coil voltage detected during the feeding of the test current with a reference voltage which also rises with the test current, wherein the reference voltage rises from a defined starting reference voltage value to a defined end reference voltage value.

[0021] Here, the magnetization direction determination unit can in principle be implemented by any combination of hardware and / or software. Preferably, however, the magnetization direction determination unit is implemented entirely in a single appropriately configured and programmed integrated circuit (IC), and particularly preferably, in a so-called application-specific integrated circuit (ASIC).

[0022] The Wiegand sensor device according to the present invention can realize the simple and reliable determination of the magnetization direction of the Wiegand wire by the magnetization direction determination unit configured to execute the method according to the present invention.

[0023] In order to be able to reliably determine the magnetization direction of the Wiegand wire independently of the current temperature, in a preferred embodiment, the Wiegand sensor device according to the present invention has a temperature sensor and the magnetization direction determination unit includes a temperature compensation module, which is configured to define a starting reference voltage value and / or an ending reference voltage value based on the temperature detected by the temperature sensor.

[0024] Preferably, the temperature compensation module includes a reference value memory (also known as a look-up table) in which temperature-specific starting reference voltage values corresponding to a plurality of different temperatures and / or temperature-specific ending reference voltage values corresponding to a plurality of different temperatures are stored. In this way, it is possible to simply define the starting reference voltage value and / or the ending reference voltage value according to the temperature, and for this purpose, a particularly high-performance computing unit is not required.

[0025] Alternatively or additionally, the temperature compensation module can also include an arithmetic algorithm for calculating the starting reference voltage value and / or the ending reference voltage value from the temperature by a computing unit. In this way, it is possible to define the starting reference voltage value and / or the ending reference voltage value according to the temperature, and for this purpose, a particularly large data memory is not required. Here, for example, it can also be envisaged that the arithmetic algorithm for calculating the starting reference voltage value and / or the ending reference voltage value uses one or more reference voltage values stored in the reference value memory.

[0026] In order to be able to determine the magnetization direction of the Weigand wire particularly reliably, in a preferred embodiment of the Weigand sensor device according to the present invention, the magnetization direction determination unit includes a calibration module, which is arranged as described above to perform calibration before feeding in the test current. In particular, the calibration module is arranged to: feed a calibration current that preferably rises with time into the sensor coil, where the maximum calibration current value is equivalent to 1 / N of the maximum test current value; detect the sensor coil voltage during the feeding of the calibration current; and define the end reference voltage value as the sum of the start reference voltage value and N times the maximum sensor coil voltage value detected during the feeding of the calibration current.

[0027] Preferably, the calibration module is arranged here to compare the sensor coil voltage detected during the feeding of the calibration current with a constant calibration reference voltage value, which is greater than (preferably only slightly greater than) the product of the maximum calibration current value and the resistance of the sensor coil, and if the sensor coil voltage detected during the feeding of the calibration current exceeds the calibration reference voltage value, then the feeding of the test current is not allowed and the magnetization direction is determined as the first magnetization direction value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments of the present invention are described below with the aid of the drawings. Among them: Figure 1 A schematic diagram of the principle of the Weigand sensor device according to the present invention is shown, Figure 2 It shows according to Figure 1 A schematic diagram of the principle of the magnetization direction determination unit of the Weigand sensor device, Figure 3 It shows the test current fed into Figure 1 The sensor coil of the Weigand sensor device, an exemplary time curve of the sensor coil voltage detected during the feeding of the test current, and the reference voltage in the case where a Weigand voltage pulse is induced in the sensor coil, Figure 4 It shows the test current, the sensor coil voltage detected during the feeding of the test current, and Figure 3 The time curve of the reference voltage, but for the case where no Weigand voltage pulse is induced in the sensor coil, Figure 5 It shows Figure 1 A schematic diagram of the principle of an alternative magnetization direction determination unit of the Weigand sensor device, Figure 6 It shows the test current fed into Figure 1Exemplary time curves of the calibration current of the sensor coil of a Weigand sensor device, the time curve of the sensor coil voltage detected during the feeding of the calibration current, and the calibration reference voltage value, for the case where no Weigand voltage pulse is induced in the sensor coil, Figure 7 Show the time curve of the calibration current, the time curve of the sensor coil voltage detected during the feeding of the calibration current, and the time values of the calibration reference voltage value, but for the case where a Weigand voltage pulse is induced in the sensor coil. Detailed Description

[0029] Figure 1 Shows a Weigand sensor device 100, which has a Weigand sensor 1 and a circuit device 2 electrically connected to the sensor coil 12. The Weigand sensor includes a Weigand wire 11 and a sensor coil 12 that radially surrounds the Weigand wire 11. The circuit device 2 includes an application-specific integrated circuit (ASIC) 21, a microcontroller 22, and a data memory 23, which together form a magnetization direction determination unit 3.

[0030] The ASIC 21 includes a temperature sensor 211, a controlled current source circuit 212, a reference voltage generator circuit 213, and a comparator circuit 214. The microcontroller 22 includes a temperature compensation module 221 implemented in software, to which the temperature T detected by the temperature sensor 211 is provided.

[0031] The temperature compensation module 221 is configured to define a current start reference voltage value URa and a current end reference voltage value URe based on the temperature T.

[0032] The temperature compensation module 221 includes a reference value memory 2211, in which a plurality of temperature-specific start reference voltage values URa(T1)-URa(Tn) corresponding to different temperatures T1-Tn and a plurality of temperature-specific end reference voltage values URe(T1)-URe(Tn) corresponding to a plurality of different temperatures T1-Tn are stored. The temperature compensation module 221 further includes an arithmetic algorithm 2212, which is configured to calculate the current start reference voltage value URa and the current end reference voltage value URe based on the temperature T and the temperature-specific start reference voltage values URa(T1)-URa(Tn) and temperature-specific end reference voltage values URe(T1)-URe(Tn) stored in the reference value memory 2211.

[0033] It should be noted here that the temperature compensation module may alternatively include only the reference value memory 2211 or only the arithmetic algorithm 2212. In the first case, the temperature compensation module 221 is configured to define the current starting reference voltage value URa and the current ending reference voltage value URe by reading the temperature-specific starting reference voltage value URa(T) corresponding to the temperature T and reading the temperature-specific ending reference voltage value URe(T) corresponding to the temperature T from the reference value memory 2211. In the second case, the arithmetic algorithm 2212 is configured to calculate the current starting reference voltage value URa and the current ending reference voltage value URe based only on the temperature T.

[0034] It should also be noted that the temperature compensation module 221 may also be configured to define only the current starting reference voltage value URa or only the current ending reference voltage value URe. In this case, the corresponding other reference voltage value URa, URe is a constant.

[0035] The current starting reference voltage value URa and the current ending reference voltage value URe are provided to the reference voltage generator circuit 213. The reference voltage generator circuit 213 is configured to generate a reference voltage UR that linearly rises from the current starting reference voltage value URa to the current ending reference voltage value URe over time t.

[0036] The controlled current source circuit 212 is configured to feed a test current Ip that rises linearly over time t into the sensor coil 12, where a maximum test current value Ip-max higher than the maximum test current parameter PIp-max is set.

[0037] The sensor coil voltage US and the reference voltage UR are provided to the comparator circuit 214. The comparator circuit 214 is configured to determine a magnetization direction value M representing the magnetization direction of the Weigand wire 11 by comparing the sensor coil voltage US with the reference voltage UR and write the magnetization direction value into the data memory 23. In particular, the comparator circuit 214 is configured to: if the sensor coil voltage US exceeds the reference voltage UR within a defined minimum over-duration, write the first magnetization direction value M = 1 into the data, and in other cases write the second reference voltage value M = 0 into the data memory 23.

[0038] Figure 3 Exemplarily shown is the time curve of the test current Ip, the sensor coil voltage US, and the reference voltage UR for the case where a Weigand voltage pulse WP is induced in the sensor coil 12. Figure 4 Shows Figure 3 the time curves of the test current Ip, the sensor coil voltage US, and the reference voltage UR in, but for the case where no Weigand voltage pulse WP is induced in the sensor coil 12.

[0039] Figure 5 shows an alternative magnetization direction determination unit 3' according to the present invention, which is formed by an alternatively arranged microcontroller 22' of the circuit device 2 for Figure 1 . The microcontroller 22' mainly differs from the microcontroller 22 in Figure 2 that the microcontroller 22' has a calibration module 222 for defining the current starting reference voltage value URa and the current ending reference voltage value URe instead of having a temperature compensation module 221.

[0040] The calibration module 222 includes a calibration coefficient memory 2221 storing the calibration coefficient N, a calibration parameter determination module 2222 implemented in software, a calibration sensor coil detection module 2223 implemented in software, and a calibration analysis module 2224 implemented in software.

[0041] The calibration parameter determination module 2222 is configured to determine the maximum calibration current parameter PIk-max based on the calibration coefficient N, where the maximum calibration current parameter is equivalent to 1 / N of the maximum test current parameter PIp-max. The calibration parameter determination module 2222 is further configured to determine the calibration reference voltage value URk, which is greater than (preferably only slightly greater than) the product of the maximum calibration current parameter PIk-max and the resistance of the sensor coil 12. The calibration parameter determination module 2222 is configured to provide the maximum calibration current parameter PIk-max to the controlled current source circuit 212, so that the controlled current source circuit feeds a calibration current Ik into the sensor coil 12, and the calibration current linearly rises with time t to a predetermined maximum calibration current value Ik-max higher than the maximum calibration current parameter PIk-max.

[0042] The calibration sensor coil detection module 2223 is configured to detect the calibration sensor coil voltage USk during the feeding of the calibration current Ik.

[0043] The calibration analysis module 2224 is configured to compare the calibration sensor coil voltage USk with the calibration reference voltage value URk. The calibration analysis module 2224 is configured to: if the calibration sensor coil voltage USk does not exceed the calibration reference voltage value URk, determine the maximum calibration sensor coil voltage USk-max, define the current starting reference voltage value URa as the calibration reference voltage value URk, and define the current ending reference voltage value URe as the sum of the current starting reference voltage value URa and N times the maximum calibration sensor coil voltage USk-max. In addition, the calibration analysis module 2224 is configured to: if the calibration sensor coil voltage USk exceeds the calibration reference voltage value URk, write the first magnetization direction value M = 1 into the data memory 23.

[0044] Figure 6 Exemplarily shown are the time curves of the calibration current Ik and the calibration sensor coil voltage USk, as well as the calibration reference voltage value URk, for the case where no Wiegand voltage pulse WP is induced in the sensor coil 12. Figure 7 Shown are the time curves of the calibration current Ik and the calibration sensor coil voltage USk, as well as the calibration reference voltage value URk, but for the case where a Wiegand voltage pulse WP is induced in the sensor coil 12.

[0045] The magnetization direction determination unit 3’ is configured to: after defining the current starting reference voltage value URa and the current ending reference voltage value URe by the calibration module 222, generate the reference voltage UR by means of the reference voltage generator circuit 213 as described above, feed the test current Ip into the sensor coil 12 by means of the controlled current source circuit 212, and compare the sensor coil voltage US with the reference voltage UR during the feeding of the test current Ip by means of the comparator circuit 214 to determine the magnetization direction value M.

[0046] List of Reference Numerals 100 Wiegand sensor device 1 Wiegand sensor 11 Wiegand wire 12 Sensor coil 2 Circuit device 21 Application specific integrated circuit (ASIC) 211 Temperature sensor 212 Controlled current source circuit 213 Reference voltage generator module 214 Comparator circuit 22, 22’ Microcontroller 221 Temperature compensation module 2211 Reference value memory 2212 Arithmetic algorithm 222 Calibration module 2221 Calibration coefficient memory 2222 Calibration parameter determination module 2223 Calibration sensor coil detection module 2224 Calibration analysis module 23 Data memory 3, 3’ Magnetization direction determination unit Ik Calibration current Ik-max Maximum calibration current value Ip Test current Ip-max Maximum test current value M Magnetization direction value N calibration coefficient PIk-max maximum calibration current parameter PIp-max maximum test current parameter S stop signal t time T detected temperature T1-Tn temperature UR reference voltage URa starting reference voltage value URa (T1-Tn) temperature-specific starting reference voltage value URe ending reference voltage value Ure (T1-Tn) temperature-specific ending reference voltage value URk calibration reference voltage value US sensor coil voltage USk calibration sensor coil voltage USk-max maximum calibration sensor coil voltage WP Wiegand voltage pulse.

Claims

1. A method for determining the magnetization direction (M) of a Weigand wire (11), wherein: - A test current (Ip) that rises with time (t) is fed into a sensor coil (12) surrounding the Weigand wire (11), and - During the feeding of the test current (Ip), a sensor coil voltage (US) present on the sensor coil (12) is detected, characterized in that the magnetization direction (M) is determined by comparing the detected sensor coil voltage (US) during the feeding of the test current with a reference voltage (UR) that rises simultaneously with the test current (Ip), wherein the reference voltage rises from a defined starting reference voltage value (URa) to a defined ending reference voltage value (URe).

2. The method according to claim 1, wherein: - The temperature (T) is detected, and - Based on the detected temperature (T), the starting reference voltage value (URa) and / or the ending reference voltage value (URe) are defined.

3. The method according to any one of the preceding claims, wherein: - Before feeding the test current (Ip), a calibration current (Ik) is fed into the sensor coil (12), wherein the maximum calibration current value (Ik-max) is equivalent to 1 / N of the maximum test current value (Ip-max), - During the feeding of the calibration current (Ik), the sensor coil voltage (USk) is detected, and - The ending reference voltage value (URe) is defined as the sum of the starting reference voltage value (URa) and N times the maximum sensor coil voltage value (USk-max) detected during the feeding of the calibration current.

4. The method according to claim 3, wherein: - The detected sensor coil voltage (USk) during the feeding of the detection current (Ik) is compared with a calibration reference voltage value (URk), the calibration reference voltage value being greater than the product of the maximum calibration current value (Ik-max) and the resistance of the sensor coil (12), and - If the detected sensor coil voltage (USk) during the feeding of the detection current (Ik) exceeds the calibration reference voltage value (URk), the magnetization direction (M) is determined as a first magnetization direction value (M = 1).

5. A Weigand sensor device (100), the Weigand sensor device comprising: - A Weigand wire (11) and - A sensor coil (12), the sensor coil (12) surrounding the Weigand wire (11), characterized in that there is a magnetization direction determination unit (3), the magnetization direction determination unit being arranged to: - Feed a test current (Ip) that rises with time (t) into the sensor coil (12), and - During the feeding of the test current (Ip), detect a sensor coil voltage (US) present on the sensor coil (12), and - The magnetization direction (M) of the Wiegand wire (11) is determined by comparing the sensor voltage (US) detected during the feeding of the test current (Ip) with a reference voltage (UR) that rises simultaneously with the test current (Ip), wherein the reference voltage (UR) rises from a defined starting reference voltage value (URa) to a defined ending reference voltage value (URe).

6. The Wiegand sensor device (100) according to claim 5, wherein the Wiegand sensor device additionally comprises a temperature sensor (211), where The magnetization direction determination unit (3) includes a temperature compensation module (221), and the temperature compensation module is configured to: define the starting reference voltage value (URa) and / or the ending reference voltage value (URe) based on the temperature (T) detected by the temperature sensor (211).

7. The Weigand sensor device (100) according to claim 6, wherein, The temperature compensation module (221) includes a reference value memory (2211), in which a plurality of temperature-specific starting reference voltage values (URa(T1)-URa(Tn)) corresponding to different temperatures (T1-Tn) and / or a plurality of temperature-specific ending reference voltage values (URe(T1)-URe(Tn)) corresponding to different temperatures (T1-Tn) are stored.

8. The Wiegand sensor device (100) according to claim 6 or 7, wherein, The temperature compensation module (221) includes an operation algorithm (2212), and the operation algorithm is used to calculate the starting reference voltage value (URa) and / or the ending reference voltage value (URe) according to the temperature.

9. The Wiegand sensor device (100) according to claim 5, wherein, The magnetization direction determination unit (3) includes a calibration module (222), and the calibration module is configured to: - Feed a calibration current (Ik) into the sensor coil (12) before feeding the test current (Ip), wherein the maximum calibration current value (Ik-max) is equivalent to 1 / N of the maximum test current value (Ip-max), - Detect the sensor coil voltage (USk) during the feeding of the calibration current (Ik), and - Define the ending reference voltage value (URe) as the sum of the starting reference voltage value (URa) and N times the maximum sensor coil voltage value (USk-max) detected during the feeding of the calibration current (Ik).

10. The Wiegand sensor device (100) according to claim 9, wherein, The calibration module (222) is configured to: - Compare the sensor coil voltage (USk) detected during the feeding of the calibration current (Ik) with a calibration reference voltage value (URk), and the calibration reference voltage value is greater than the product of the maximum calibration current value (Ik-max) and the resistance of the sensor coil (12), and - If the sensor coil voltage (USk) detected during the feeding of the calibration current (Ik) exceeds the calibration reference voltage value (URk), then determine the magnetization direction (M) as the first magnetization direction value (M = 1).

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