Method for determining a magnetization direction of a wiegand wire, and wiegand sensor arrangement

Abstract

The present invention relates to a method for determining a magnetization direction (M) of a Wiegand wire (11), wherein: a test current (Ip) that increases over time (t) is injected into a sensor coil (12) surrounding the Wiegand wire (11), a sensor coil voltage (US) present at the sensor coil (12) is captured during the injection of the test current (Ip), and the magnetization direction (M) is determined by comparing the sensor coil voltage (US) captured during the injection of the test current with a reference voltage (UR) that increases at the same time as the test current (Ip), wherein the reference voltage (UR) increases, starting from a defined starting reference voltage value (URa), to a defined end reference voltage value (URe). The present invention also relates to a Wiegand sensor arrangement (100) comprising: a Wiegand wire (11) and a sensor coil (12) surrounding the Wiegand wire (11), wherein there is a magnetization direction determination unit (3) which is configured to carry out a method according to the invention for determining a magnetization direction (M) of the Wiegand wire (11).

Description

[0001] DESCRIPTION

[0002] Method for determining a magnetization direction of a Wiegand wire and Wiegand sensor arrangement

[0003] The present invention relates to a method for determining the magnetization direction of a Wiegand wire, wherein: a test current that increases over time is impressed into a sensor coil surrounding the Wiegand wire, and a sensor coil voltage applied to the sensor coil is detected while the test current is impressed. The present invention further relates to a Wiegand sensor arrangement comprising: a Wiegand wire and a sensor coil surrounding the Wiegand wire.

[0004] A Wiegand wire, as used in this application, is also referred to as a pulse wire and generally has a hard magnetic sheath and a soft magnetic core, or vice versa. Under the influence of an external magnetic field, the magnetization direction of the Wiegand wire suddenly inverts, generating a short Wiegand voltage pulse in a sensor coil radially surrounding the Wiegand wire, which can be tapped via both ends of the sensor coil. This effect is known as the Wiegand effect and is well known in the art.

[0005] For example, in a rotary encoder, knowledge of the magnetization direction of the Wiegand wire is important to perform synchronization between a Wiegand sensor-based revolution counter sensor unit, also known as a multiturn sensor unit, and a fine position sensor unit, also known as a singleturn sensor unit.

[0006] Against this background, EP 1 565 755 B1 discloses a method for determining a magnetization direction of a Wiegand wire, wherein an increasing test current is impressed into a sensor coil surrounding the Wiegand wire and, during the impression of the test current, a sensor coil voltage applied to the sensor coil is detected and evaluated.

[0007] The object of the present invention is to enable a relatively simple and reliable determination of the magnetization direction of a Wiegand wire.

[0008] This object is achieved by a method for determining a magnetization direction of a Wiegand wire having the features of claim 1.

[0009] In the method according to the invention for determining a magnetization direction of a Wiegand wire, a test current that increases over time is impressed into a sensor coil surrounding the Wiegand wire in order to generate a test magnetic field acting on the Wiegand wire. Preferably, the test current increases continuously, i.e. steadily, from zero following a defined test current curve. Particularly preferably, the test current increases linearly with a defined gradient. The test current curve 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, e.g., for different temperatures. If the magnetization direction is reversed by the generated test magnetic field, a so-called Wiegand voltage pulse is induced in the sensor coil by the Wiegand wire.Based on the occurrence or non-occurrence of a Wiegand voltage pulse, it can therefore be determined whether the magnetization direction of the Wiegand wire was aligned or opposite to the test magnetic field before the test current was applied.

[0010] In the method according to the invention for determining a magnetization direction of a Wiegand wire, a sensor coil voltage applied to the sensor coil is therefore detected and evaluated during the application of the test current.

[0011] In order to determine whether or not a Wiegand voltage pulse has been induced in the sensor coil, and thereby to determine the magnetization direction of the Wiegand wire, according to the invention the sensor coil voltage detected during the application of the test current is compared with a reference voltage that increases simultaneously and preferably uniformly with the test current and that increases from a defined start reference voltage value to a defined end reference voltage value. The start reference voltage value and the end reference voltage value can be defined both directly and indirectly, for example via a predetermined mathematical relationship. Preferably, the reference voltage increases continuously, particularly preferably linearly. For example, it is conceivable that the end reference voltage value is defined indirectly via a predetermined gradient of the reference voltage.The comparison of the sensor coil voltage with the reference voltage is preferably carried out using appropriate hardware, for example, a comparator, which compares the sensor coil voltage detected at the sensor coil with a reference voltage signal that increases simultaneously with the test current. However, the comparison of the sensor coil voltage with the reference voltage can also be implemented in software, with a signal representing the detected sensor coil voltage being used.

[0012] Sensor coil voltage variable is compared with a reference voltage variable that increases simultaneously with the test current.

[0013] The magnetization direction is determined depending on whether the sensor coil voltage exceeds the reference voltage during the application of the test current, i.e., whether it is greater in magnitude than the reference voltage. If the sensor coil voltage exceeds the reference voltage, it is assumed that a Wiegand voltage pulse was induced and, consequently, the Wiegand wire had a magnetization direction opposite to the test magnetic field before the application of the test current. In this case, the magnetization direction is set to a first magnetization direction value. If, on the other hand, the sensor coil voltage does not exceed the reference voltage, it is assumed that no Wiegand voltage pulse was induced and, consequently, the Wiegand wire had a magnetization direction parallel to the test magnetic field before the application of the test current.In this case, the magnetization direction is set to a second magnetization direction value. To avoid incorrect determination of the magnetization direction due to voltage fluctuations, it can be advantageous to provide a specified minimum exceedance duration as the criterion for exceeding the value, i.e., to only set the magnetization direction to the first magnetization direction value if the sensor coil voltage exceeds the reference voltage for the minimum exceedance duration. The determined magnetization direction value is typically stored in a data memory. However, it is also conceivable that the magnetization direction value is not stored but merely processed. For example, a revolution count value can be determined or corrected based on the determined magnetization direction value.

[0014] The method according to the invention therefore enables a simple and reliable determination of the magnetization direction of a Wiegand wire.

[0015] The electrical properties of the sensor coil, in particular the electrical resistance of the sensor coil, are generally temperature-dependent, so that a voltage drop across the sensor coil caused by the application of the test current to the sensor coil is also temperature-dependent according to Ohm's law. Therefore, in the method according to the invention, a temperature is preferably detected and the starting reference voltage value and / or the end reference voltage value are defined based on the detected temperature in order to enable a reliable determination of the magnetization direction of the Wiegand wire, independent of the current temperature.

[0016] In a preferred embodiment of the method according to the invention, a calibration is performed before the test current is applied. A calibration current, preferably increasing over time, is applied to the sensor coil, which has a maximum calibration current value corresponding to 1 / N times the maximum test current value of the test current, and the sensor coil voltage is recorded during this time. The final reference voltage value, up to which the reference voltage increases, is then defined as the sum of the starting reference voltage value and N times the maximum sensor coil voltage value recorded during the calibration current application.The final reference voltage value is therefore always greater than a maximum voltage drop across the sensor coil caused by the test current, so that exceeding the reference voltage due to the sensor coil voltage caused solely by the test current can be reliably avoided regardless of the current measuring conditions.

[0017] Preferably, the sensor coil voltage detected during the application of the calibration current is compared with a constant calibration reference voltage value, which is - preferably only slightly - greater than the product of the maximum calibration current value and an electrical resistance of the sensor coil, in order to determine whether or not a Wiegand voltage pulse was induced in the sensor coil during calibration. If the sensor coil voltage detected during the application of the calibration current exceeds the calibration reference voltage value, it is assumed that a Wiegand voltage pulse was induced and, consequently, the magnetization direction is set to the first magnetization direction value. To avoid incorrect determination of the magnetization direction due to voltage fluctuations, it can also be advantageous here to provide a specified minimum excess duration as a criterion for the excess.To avoid so-called cripple pulses, after calibration, even though the magnetization direction is already known, the test current is preferably still impressed into the sensor coil in order to completely magnetize the Wiegand wire.

[0018] The above-mentioned object is further achieved by a Wiegand sensor arrangement having the features of claim 5. The Wiegand sensor arrangement according to the invention comprises a Wiegand wire and a sensor coil that radially surrounds the Wiegand wire. Such an arrangement of a Wiegand wire and a sensor coil is well known in the art and is also referred to as a Wiegand sensor.

[0019] According to the invention, the Wiegand sensor arrangement comprises a magnetization direction determination unit which is electrically connected to the sensor coil and which is configured to carry out a method according to the invention for determining a magnetization direction of the Wiegand wire.

[0020] Specifically, the magnetization direction determination unit is configured to inject a test current that increases over time into the sensor coil and, during this time, to detect a sensor coil voltage present at the sensor coil. For this purpose, the magnetization direction determination unit typically comprises a controllable current source configured in any known manner and a voltage measuring device configured in any known manner.

[0021] Furthermore, the magnetization direction determination unit is configured, as already described above for the method according to the invention, to determine a magnetization direction of the Wiegand wire by comparing the sensor coil voltage detected during the application of the test current with a reference voltage which increases simultaneously with the test current and which increases from a defined start reference voltage value to a defined end reference voltage value.

[0022] The magnetization direction determination unit can, in principle, be implemented using any combination of hardware and / or software. However, the magnetization direction determination unit is preferably implemented entirely in a single, appropriately structured and programmed integrated circuit (IC), particularly preferably in an application-specific integrated circuit (ASIC).

[0023] The Wiegand sensor arrangement according to the invention enables a simple and reliable determination of the magnetization direction of the Wiegand wire by means of the magnetization direction determination unit configured to carry out a method according to the invention.

[0024] In order to enable a reliable determination of the magnetization direction of the Wiegand wire, independent of the current temperature, the Wiegand sensor arrangement according to the invention has, in a preferred embodiment, a temperature sensor and the magnetization direction determination unit comprises a

[0025] Temperature compensation module configured to define the start reference voltage value and / or the end reference voltage value based on a temperature detected by the temperature sensor.

[0026] The temperature compensation module preferably comprises a reference value memory, also known as a look-up table, in which several temperature-specific starting reference voltage values ​​assigned to different temperatures and / or several temperature-specific ending reference voltage values ​​assigned to different temperatures are stored. This enables a simple temperature-dependent definition of the starting reference voltage value and / or the ending reference voltage value, for which no particularly powerful computing unit is required. Alternatively or additionally, the temperature compensation module can also comprise a calculation algorithm for the temperature-dependent calculation of the starting reference voltage value and / or the ending reference voltage value by a computing unit.This enables a temperature-dependent definition of the starting reference voltage value and / or the end reference voltage value, which does not require a particularly large data memory. For example, it is also conceivable that the calculation algorithm for calculating the starting reference voltage value and / or the end reference voltage value uses one or more reference voltage values ​​stored in the reference value memory.

[0027] To enable a particularly reliable determination of the magnetization direction of the Wiegand wire, in a preferred embodiment of the Wiegand sensor arrangement according to the invention, the magnetization direction determination unit comprises a calibration module configured, as described above, to perform a calibration before applying the test current. Specifically, the calibration module is configured to apply a preferably temporally increasing calibration current to the sensor coil, wherein a maximum calibration current value corresponds to 1 / N times a maximum test current value, to detect the sensor coil voltage while applying the calibration current, and to define the final reference voltage value as the sum of the starting reference voltage value and N times a maximum sensor coil voltage value detected while applying the calibration current.

[0028] Preferably, the calibration module is configured to compare the sensor coil voltage detected during the application of the calibration current with a constant calibration reference voltage value which is - preferably only slightly - greater than the product of the maximum calibration current value and an electrical resistance of the sensor coil, and, if the sensor coil voltage detected during the application of the calibration current exceeds the calibration reference voltage value, to prevent the application of the test current and to set the magnetization direction to a first magnetization direction value.

[0029] Embodiments of the present invention are described below with reference to the accompanying figures. Herein:

[0030] Fig. 1 is a schematic diagram of a Wiegand sensor arrangement according to the invention,

[0031] Fig. 2 a schematic diagram of a

[0032] Magnetization direction determination unit of the

[0033] Wiegand sensor arrangement from Fig. 1,

[0034] Fig. 3 shows exemplary time profiles of a test current impressed into a sensor coil of the Wiegand sensor arrangement from Fig. 1, a sensor coil voltage detected during the impression of the test current and a reference voltage, in the case that a Wiegand voltage pulse is induced into the sensor coil,

[0035] Fig. 4 shows the time profiles of the test current, the sensor coil voltage detected during the impression of the test current and the reference voltage from Fig. 3, but for the case that no Wiegand voltage pulse is induced in the sensor coil, Fig. 5 shows a schematic diagram of an alternative

[0036] Magnetization direction determination unit of the

[0037] Wiegand sensor arrangement from Fig. 1,

[0038] Fig. 6 shows exemplary time profiles of a calibration current impressed into a sensor coil of the Wiegand sensor arrangement from Fig. 1 and a sensor coil voltage detected during the impression of the calibration current as well as a calibration reference voltage value, in the case that no Wiegand voltage pulse is induced into the sensor coil, and

[0039] Fig. 7 shows the time courses of the calibration current and the sensor coil voltage detected during the impression of the calibration current as well as the calibration reference voltage value, but for the case that a Wiegand voltage pulse is induced in the sensor coil.

[0040] Fig. 1 shows a Wiegand sensor arrangement 100 with a Wiegand sensor 1 comprising a Wiegand wire 11 and a sensor coil 12 radially surrounding the Wiegand wire 11, and with a circuit arrangement 2 electrically connected to the sensor coil 12. The circuit arrangement 2 comprises an application-specific integrated circuit (ASIC) 21, a microcontroller 22, and a data memory 23, which together form a magnetization direction determination unit 3.

[0041] The ASIC 21 comprises a temperature sensor 211, a regulated current source circuit 212, a reference voltage generator circuit 213, and a comparator circuit 214. The microcontroller 22 comprises a temperature compensation module 221 implemented in software, to which a temperature T detected by the temperature sensor 211 is provided.

[0042] 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.

[0043] The temperature compensation module 221 comprises a reference value memory 2211 in which a plurality of temperature-specific starting reference voltage values ​​URa(Tl)-URa(Tn) assigned to different temperatures Tl-Tn and a plurality of temperature-specific end reference voltage values ​​URe(Tl)-URe(Tn) assigned to different temperatures Tl-Tn are stored. The temperature compensation module 221 further comprises a calculation algorithm 2212 configured to calculate the current starting reference voltage value URa and the current end reference voltage value URe based on the temperature T and the temperature-specific starting reference voltage values ​​URa(Tl)-URa(Tn) and the temperature-specific end reference voltage values ​​URe(Tl)-URe(Tn) stored in the reference value memory 2211.

[0044] At this point, it should be noted that the temperature compensation module 221 can alternatively comprise only one reference value memory 2211 or only one calculation algorithm 2212. In the first case, the temperature compensation module 221 is configured to define the current start reference voltage value URa and the current end reference voltage value URe by reading the temperature-specific start reference voltage value URa(T) assigned to the temperature T and the temperature-specific end reference voltage value URe(T) assigned to the temperature T from the reference value memory 2211. In the second case, the calculation algorithm 2212 is configured to define the current start reference voltage value URa and the current end

[0045] Reference voltage value URe to be calculated only based on temperature T.

[0046] Furthermore, it should be noted that the temperature compensation module 221 can 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 other reference voltage value URa, URe is a constant.

[0047] The reference voltage generator circuit 213 is provided with the current start reference voltage value URa and the current end reference voltage value URe.

[0048] Reference voltage generator circuit 213 is configured to generate a reference voltage UR that increases linearly with time t from the current start reference voltage value URa to the current end reference voltage value URe.

[0049] The regulated current source circuit 212 is configured to inject a test current Ip into the sensor coil 12 which increases linearly with time t, wherein a maximum test current value Ip-max is predetermined via a maximum test current parameter PIp-max.

[0050] 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 indicating the magnetization direction of the Wiegand wire 11 by comparing the sensor coil voltage US with the reference voltage UR and to write it into the data memory 23. Specifically, the comparator circuit 214 is configured to write a first magnetization direction value M = 1 into the data memory 23 if the sensor coil voltage US exceeds the reference voltage UR for a defined minimum excess duration, and otherwise to write a second magnetization direction value M = 0 into the data memory 23.

[0051] Fig. 3 shows, by way of example, the time profiles of the test current Ip, the sensor coil voltage US, and the reference voltage UR for the case that a Wiegand voltage pulse WP is induced into the sensor coil 12. Fig. 4 shows the time profiles of the test current Ip, the sensor coil voltage US, and the reference voltage UR from Fig. 3, but for the case that no Wiegand voltage pulse WP is induced into the sensor coil 12.

[0052] Fig. 5 shows an alternative magnetization direction determination unit 3' according to the invention, which is formed by an alternatively configured microcontroller 22' for the circuit arrangement 2 from Fig. 1. The microcontroller 22' differs from the microcontroller 22 from Fig. 2 essentially in that the microcontroller 22' has a calibration module 222 for defining the current start reference voltage value URa and the current end reference voltage value URe instead of the temperature compensation module 221.

[0053] The calibration module 222 comprises a calibration factor memory 2221 in which a calibration factor N is stored, a software-implemented calibration parameter determination module 2222, a software-implemented calibration sensor coil detection module 2223, and a software-implemented calibration evaluation module 2224. The calibration parameter determination module 2222 is configured to determine, based on the calibration factor N, a maximum calibration current parameter PIk-max, which corresponds to 1 / N times the maximum test current parameter PIp-max. The calibration parameter determination module 2222 is further configured to determine a calibration reference voltage value URk, which is—preferably only slightly—greater than the product of the maximum calibration current parameter PIk-max and an electrical 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 regulated current source circuit 212, so that the latter injects a calibration current Ik into the sensor coil 12 that increases linearly with time t up to a maximum calibration current value Ik-max specified by the maximum calibration current parameter PIk-max.

[0054] The calibration sensor coil detection module 2223 is configured to detect a calibration sensor coil voltage USk while impressing the calibration current Ik.

[0055] The calibration evaluation module 2224 is set up, the calibration

[0056] Sensor coil voltage USk with the calibration

[0057] Reference voltage value URk. The calibration

[0058] Evaluation module 2224 is set up if the calibration

[0059] Sensor coil voltage USk the calibration reference voltage value

[0060] URk does not exceed: a maximum calibration

[0061] Sensor coil voltage value USk-max to determine the current start

[0062] Reference voltage value URa as the calibration

[0063] Reference voltage value URk to be defined and the current final

[0064] Reference voltage value URe as the sum of the current start-

[0065] Reference voltage value URa and N times the maximum calibration sensor coil voltage value USk-max. Furthermore, the calibration evaluation module 2224 is configured to write the first magnetization direction value M = 1 into the data memory 23 if the calibration sensor coil voltage USk exceeds the calibration reference voltage value URk.

[0066] Fig. 6 shows, by way of example, the time profiles of the calibration current Ik and the calibration sensor coil voltage USk, as well as the calibration reference voltage value URk, for the case that no Wiegand voltage pulse WP is induced into the sensor coil 12. Fig. 7 shows the time profiles of the calibration current Ik and the calibration sensor coil voltage USk, as well as the calibration reference voltage value URk from Fig. 6, but for the case that a Wiegand voltage pulse WP is induced into the sensor coil 12.

[0067] The magnetization direction determination unit 3' is configured, after the current start reference voltage value URa and the current end reference voltage value URe have been defined by the calibration module 222, to generate the reference voltage UR by means of the reference voltage generator circuit 213 as described above, to inject the test current Ip into the sensor coil 12 by means of the regulated current source circuit 212, and to compare the sensor coil voltage US with the reference voltage UR by means of the comparator circuit 214 while injecting the test current Ip in order to determine the magnetization direction value M. List of Reference Symbols

[0068] 100 Wiegand sensor arrangement

[0069] 1 Wiegand sensor

[0070] 11 Wiegand wire

[0071] 12 Sensor coil

[0072] 2 Circuit arrangement

[0073] 21 application-specific integrated circuit (ASIC)

[0074] 211 Temperature sensor

[0075] 212 regulated current source circuit

[0076] 213 Reference voltage generator module

[0077] 214 Comparator circuit

[0078] 22; 22' microcontroller

[0079] 221 Temperature compensation module

[0080] 2211 Reference value memory

[0081] 2212 calculation algorithm

[0082] 222 Calibration module

[0083] 2221 Calibration factor memory

[0084] 2222 Calibration parameter determination module

[0085] 2223 Calibration Sensor Coil Acquisition Module

[0086] 2224 Calibration evaluation module

[0087] 23 data storage

[0088] 3; 3' Magnetization direction determination unit

[0089] Ik calibration current

[0090] Ik-max maximum calibration current value

[0091] Ip test current

[0092] Ip-max maximum test current value

[0093] M Magnetization direction value

[0094] N Calibration factor

[0095] PIk-max maximum calibration current parameter PIp-max maximum test current parameter

[0096] S Stop signal t Time

[0097] T recorded temperature Tl-Tn temperatures

[0098] UR reference voltage

[0099] URa start reference voltage value

[0100] URa(Tl-Tn) temperature-specific starting reference voltage values

[0101] URe final reference voltage value URe(Tl-Tn) temperature-specific final reference voltage values

[0102] URk calibration reference voltage value

[0103] US sensor coil voltage

[0104] USk calibration sensor coil voltage

[0105] USk-max maximum calibration sensor coil voltage value WP Wiegand voltage pulse

Claims

PATENT CLAIMS 1. A method for determining a magnetization direction (M) of a Wiegand wire (11), wherein: - a test current (Ip) increasing with time (t) is impressed into a sensor coil (12) surrounding the Wiegand wire (11), and - during the application of the test current (Ip), a sensor coil voltage (US) applied to the sensor coil (12) is detected, characterized in that the magnetization direction (M) is determined by comparing the sensor coil voltage (US) detected during the application of the test current with a reference voltage (UR) which increases simultaneously with the test current (Ip), the reference voltage (UR) increasing from a defined start reference voltage value (URa) to a defined end reference voltage value (URe).

2. The method according to claim 1, wherein: - a temperature (T) is recorded, and - the start reference voltage value (URa) and / or the end reference voltage value (URe) is defined based on the detected temperature (T).

3. Method according to one of the preceding claims, wherein: - before applying the test current (Ip), a calibration current (Ik) is applied to the sensor coil (12), wherein a maximum calibration current value (Ik-max) corresponds to 1 / N times a maximum test current value (Ip-max), - the sensor coil voltage (USk) is recorded while the calibration current (Ik) is applied, and - the final reference voltage value (URe) is defined as the sum of the start reference voltage value (URa) and N times a maximum sensor coil voltage value (USk-max) recorded during the application of the calibration current.

4. The method according to claim 3, wherein: - the sensor coil voltage (USk) detected during the application of the calibration current (Ik) is compared with a calibration reference voltage value (URk) which is greater than the product of the maximum calibration current value (Ik-max) and an electrical resistance of the sensor coil (12), and - if the sensor coil voltage (USk) detected during the application of the calibration current (Ik) exceeds the calibration reference voltage value (URk), the magnetization direction (M) is set to a first magnetization direction value (M = l).

5. Wiegand sensor arrangement (100) comprising: - a Wiegand wire (11) and - a sensor coil (12) surrounding the Wiegand wire (11), characterized in that a magnetization direction determination unit (3) is provided which is configured: - to inject a test current (Ip) increasing with time (t) into the sensor coil (12), - during the application of the test current (Ip) a voltage applied to the to detect the sensor coil voltage (US) applied to the sensor coil (12), and - to determine a magnetization direction (M) of the Wiegand wire (11) by comparing the sensor coil voltage (US) detected during the application of the test current (Ip) with a reference voltage (UR) that increases simultaneously with the test current (Ip), wherein the reference voltage (UR) increases from a defined start reference voltage value (URa) to a defined end reference voltage value (URe). ​​The Wiegand sensor arrangement (100) according to claim 5, additionally comprising a temperature sensor (211), wherein the magnetization direction determination unit (3) comprises a temperature compensation module (221) configured to define the start reference voltage value (URa) and / or the end reference voltage value (URe) based on a temperature (T) detected by the temperature sensor (211).Wiegand sensor arrangement (100) according to claim 6, wherein the temperature compensation module (221) comprises a reference value memory (2211) in which a plurality of temperature-specific start reference voltage values ​​(URa(Tl)-URa(Tn)) assigned to different temperatures (Tl-Tn) and / or a plurality of temperature-specific end reference voltage values ​​(URe(Tl)-URe(Tn)) assigned to different temperatures (Tl-Tn) are stored. Wiegand sensor arrangement (100) according to claim 6 or 7, wherein the. Temperature compensation module (221) Calculation algorithm (2212) for temperature-dependent calculation of the start reference voltage value (URa) and / or the end reference voltage value (URe). Wiegand sensor arrangement (100) according to claim 5, wherein the magnetization direction determination unit (3) comprises a calibration module (222) which is configured: - before applying the test current (Ip), a calibration current (Ik) is applied to the sensor coil (12), wherein a maximum calibration current value (Ik-max) corresponds to 1 / N times a maximum test current value (Ip-max), - to measure the sensor coil voltage (USk) while applying the calibration current (Ik), and - to define the final reference voltage value (URe) as the sum of the starting reference voltage value (URa) and N times a maximum sensor coil voltage value (USk-max) detected during the application of the calibration current (Ik). Wiegand sensor arrangement (100) according to claim 9, wherein the calibration module (222) is configured: - to compare the sensor coil voltage (USk) detected during the application of the calibration current (Ik) with a calibration reference voltage value (URk) which is greater than the product of the maximum calibration current value (Ik-max) and an electrical resistance of the sensor coil (12), and - if the sensor coil voltage (USk) detected during the application of the calibration current (Ik) exceeds the calibration reference voltage value (URk), the magnetization direction (M) is set to a first Magnetization direction value (M = l) to be determined.

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