System and method for measuring physical quantities and / or positions using a bistable magnetic wire

Abstract

A physical quantity measurement and / or position measurement system using a bistable magnetic wire (1), comprising an excitation element (2) for generating a magnetic field and a sensing element (3). Within the magnetic field of the excitation element (2), a bistable magnetic wire (1) having a first end (11) and an oppositely arranged second end (12) is arranged. The bistable magnetic wire (1) is adjusted in magnetization by a single Barkhausen jump from the first end (11) to the second end (12) or vice versa, the excitation element (2) and the bistable magnetic wire (1) are arranged in a mutual position with a magnetic field that is asymmetric with respect to the bistable magnetic wire (1), and the magnitude of the magnetic field excited by the excitation element (2) at the first end (11) is different from the magnitude of the magnetic field excited by the excitation element (2) at the second end (12). The asymmetry of the magnetic field arises due to the asymmetrical positions of the magnetic element (2) and the bistable magnetic wire (1) relative to one another and / or due to the asymmetrical structure of the magnetic element (2).

Description

[Technical Field]

[0001] The present invention relates to a composition of a magnetizing element and a bistable magnetic wire, which is prepared for measuring various physical quantities and / or for measuring the position of the bistable magnetic wire. The novelty of this system and method lies primarily in the specific asymmetric position of the magnetic field of the magnetizing element and indeed of the magnetic field of the bistable magnetic wire, which significantly improves the interpretability of the raw measurement data. [Background technology]

[0002] Bistable magnetic elements are used to measure various physical quantities and positions. They are formed by a passive member that reacts to changes in position in a magnetic field or to changes in a physical quantity by changing its magnetization.

[0003] For example, GB2374084A describes an alloy with bistable magnetic properties and a microwire made of this alloy. This microwire can respond to various physical quantities, but response evaluation is problematic because prior art bistable magnetic elements can have complex magnetic effects in which magnetization occurs in multiple regions (magnetic domains) within a single microwire, rather than a single wall jump. Applications of bistable magnetic wires for position, angle, and rotation measurements are also known.

[0004] The excitation of a bistable magnetic wire wound on a core is described in US4484090A. This solution does not allow the evaluation of physical quantities. Some magnetic effects of bistable magnetic elements are described in JPH03252577A, but the problem of interpreting the measured nonlinear values ​​is not resolved.

[0005] DE 2817169 A1, DE 3427582 A1, and SU 1753425 A1 describe systems with Wiegand wires that have a certain level of magnetic bistability, which serve to determine the proximity of the bistable magnetic element to the sensor. Due to this configuration, it is not possible to measure the value of a physical quantity in the vicinity of the bistable magnetic element.

[0006] The position or rotation sensor according to EP 0 484 716 A1 uses a Wiegand wire that is approached by a rotating permanent magnet. This sensor responds only to changes in the magnetic field and does not evaluate the magnitude of any physical quantity.

[0007] The Wiegand sensor according to DE 4107847 C1 is capable of contactlessly transmitting information about the closure of a switch which can react to changes in physical quantities such as temperature, pressure or acceleration, but requires a suitable sensor after which the switch is controlled, i.e. the physical quantity is not measured by the bistable magnetic element itself.

[0008] New technical solutions that are simple in construction, eliminate the influence of noise and secondary phenomena, and improve the reproducible interpretability of measurements of various physical quantities are desired but are not known. The bistable magnetic element must react to changes in the measured physical quantity and generate a response that is contactlessly transmitted to a receiving element. Summary of the Invention

[0009] The above-mentioned drawbacks are substantially eliminated by a system for measuring physical quantities and / or positions using a bistable magnetic wire, comprising an excitation element for generating a magnetic field within the range in which the bistable magnetic wire is disposed. The bistable magnetic wire has a first end and an oppositely disposed second end, and is therefore not wound into a screw or coil. The magnetization of the bistable magnetic wire is adjusted by a single Barkhausen front jump from the first end to the second end or vice versa. According to the present invention, the essence of the system lies in the mutual positioning of the excitation element and the bistable magnetic wire such that the magnitude (amplitude) of the magnetic field excited by the excitation element at the first end differs from the magnitude (amplitude) of the magnetic field excited by the excitation element at the second end. The magnetic fields at the first end and the second end are different at every moment of non-zero excitation, and therefore at a given moment, and the excitation is time-dynamic. The system also includes a receiving element for receiving a response from the bistable magnetic wire.

[0010] The terms first and second are used herein to refer to two different ends and are interchangeable, and do not denote the relative importance or superiority of one end of the bistable magnetic wire.

[0011] The different magnetic fields at the two ends at a given moment of excitation result in an asymmetric magnetic field, which, together with the magnetization due to a single Barkhausen jump, leads to reproducible and interpretable measurement results.For practical measurement applications, it is important that the behavior of a bistable magnetic wire is fundamentally affected by the measurand and the measurement position, and that other factors, including the effect of the more complex magnetic properties of the bistable magnetic wire, are negligible or at least identifiable in a way that allows them to be corrected when evaluating the raw data.

[0012] To ensure asymmetry between the excitation field and the relative positions of the bistable magnetic wire, a difference of 5%, preferably 10%, and particularly preferably 25% or more between the magnetic field values ​​at the first and second ends is sufficient. This ensures that magnetization occurs in a single jump across the entire wire from one end to the other. If magnetization occurs in several separate magnetic domains along the length of the wire, the measured response will contain several individual effects, significantly compromising the interpretability of the measurement. This makes it impossible to identify dependencies in the measurement data, reducing the applicability of bistable magnetic wires. The objective of this invention is to achieve effective and complete true bistable magnetization, where the magnetic domain structure of a bistable magnetic wire does not consist of multiple magnetic domains within a single wire, resulting in the generation of magnetization through multiple domain movements. While measurements of a bistable magnetic wire with multiple magnetic domains along its length can be compared to measurements of several separate bistable magnetic wires in a single excitation field, the resulting measurement is a sum of individual responses that cannot be reliably distinguished, and therefore the summarized response vector is practically unusable.

[0013] Several technical possibilities are available for creating relatively asymmetric magnetic fields, and the appropriate choice of each depends on the specific quantity or location being measured. In principle, the system according to the present invention can measure temperature, pressure / tension, and magnetic field. From these basic quantities, various relative positions as well as a whole range of other physical quantities can be indirectly measured. The presence of bistable magnetic wires can be measured by measuring their mutual position, current parameters can be measured by measuring the magnetic field in conductors, and bending and torsional stress or flow of liquids or gases can be measured by measuring their position in the Earth's magnetic field and their linear feed, or by measuring their elongation in the respective directions.

[0014] By measuring the change in the magnetic field, it is possible to detect changes in the position or rotation of the bistable magnetic wire or the carrier on which the bistable magnetic wire is mounted, and to measure the relative position of another object on which the magnetizing element is mounted, which can be used to construct position sensors, rotation sensors, edge sensors, proximity sensors for magnetic bodies or carriers with magnetic bodies, absolute position sensors relative to the Earth's magnetic field, etc.

[0015] Although the antenna of the excitation element may be used for measuring the response, the system preferably comprises a separate receiving element, for example in the form of a receiving coil. In this case, the excitation element may be a primary coil, and the receiving element is formed by a secondary coil. The secondary coil can be connected to an amplifier and an evaluation unit. The receiving elements may be arranged coaxially with the position of the bistable magnetic wire, or may be arranged at different positions from each other so as to be within range of receiving the response.

[0016] In a preferred embodiment, the bistable magnetic wire is in the form of a microwire with a diameter of less than 50 μm, preferably less than 25 μm, and particularly preferably less than 15 μm. This is because the radial magnetic structure disappears when the core diameter is less than 15 μm and the amorphous metal alloy has the appropriate composition, which is associated with the wire drawing process with simultaneous quenching, usually water quenching. As a result, the bistable magnetic wire behaves completely bistable, and is therefore effectively bistable throughout the entire length of the wire, with the magnetic domain walls during magnetization extending from the first end to the second end, rather than separately in several individual regions along the length of the wire. It has also been found to be suitable for the length of the bistable magnetic wire to be at least 100 times, preferably at least 10,000 times, its diameter, resulting in a small-diameter wire that can also be called a microwire.

[0017] A typical structure of bistable magnetic wire includes an amorphous metal core and a cover, such as a glass cover, whose outer diameter is no more than three times the diameter of the metal core. The thickness of the glass cover is 1 to 20 μm. The glass cover or glass surface layer protects the metal core from electrical contact with the environment and from aggressive chemical environments, making bistable magnetic wire very versatile, for example, directly in the windings of electric motors, inside building materials, or inside the human body. In principle, bistable magnetic wire can also be used without a circumferential cover, and covers made of materials other than glass can also be used.

[0018] As described in earlier publications by the authors of this invention, magnetic excitation by a triangular signal, usually a symmetrical triangular signal, has proven suitable, simplifying the evaluation of the measurement signal. For this purpose, the system according to this invention is adapted to be connected to a power element, a control element, and an evaluation element. Upon instruction from the control element, the power element transmits a voltage to the excitation element, the voltage being adjusted to obtain a triangular excitation signal. The evaluation element acquires and analyzes the response received from the bistable magnetic wire.

[0019] Asymmetry in the excitation field can be achieved by asymmetrically positioning the excitation element, which induces a substantially symmetric magnetic field, relative to the bistable magnetic wire. As shown in Figure 3, the positional asymmetry ensures that the first end of the bistable magnetic wire is in a higher magnetic field than the second end, so that the bistable magnetic wire is always magnetized as one of the domain walls moves in the higher magnetic field. The positional asymmetry can be achieved by establishing a spatial relationship. At the same time, the coil of the excitation element and the bistable magnetic wire can be coaxially positioned, resulting in longitudinal axes that are either aligned in the same direction or parallel to each other.

[0020] The asymmetry of the excitation field can be achieved, for example, by designing the excitation element with non-uniform coil windings with different thread pitches or thread counts at the first and second ends. This design of the excitation element results in different magnetic field magnitudes at both ends of the excitation element or at a certain distance from both ends. In this case, even if the relative positions of the excitation element and the bistable magnetic wire are spatially symmetrical, the first and second ends of the bistable magnetic wire will have different magnetic field magnitudes.

[0021] The definition of the mutual position of the excitation element and the bistable magnetic wire in the first claim also includes a symmetrical mutual position when an asymmetric magnetic field is generated by the excitation element. The definition in the first claim expresses a mutual position that can be achieved by several means or by different combinations of technical means and relative spatial arrangements. The asymmetry of the magnetic field, which is important for achieving the effect of the present invention, is always understood in terms of the relative relationship between the magnitude of the magnetic field at the first end and the second end. The asymmetry of the excitation field can also be achieved by adding a shielding element or by placing a separate secondary coil on the primary coil of the excitation element. In such cases, the mutual positions of the excitation element and the bistable magnetic wire may appear spatially symmetrical, but the asymmetry of the magnetic field at the first end and the second end becomes important.

[0022] In all versions of magnetic field asymmetry, the magnetizing element can be positioned either coaxially with or adjacent to the bistable magnetic wire. In most applications, the longitudinal axis of the magnetic field generated by the magnetizing element is assumed to be essentially parallel to the longitudinal axis of the bistable magnetic wire, although in principle, angular positions are also possible, e.g., the longitudinal axis of the magnetizing element can be offset from the longitudinal axis of the bistable magnetic wire by up to 30 degrees.

[0023] The drawbacks of the prior art are overcome by a method for measuring physical quantities and / or positions using a bistable magnetic wire, in which a variable magnetic field is transmitted by a magnetizing element, at least one bistable magnetic wire is positioned within the excitation field, and is magnetized when the field changes from a first end to a second end or vice versa by a single Barkhausen front jump. The response of the bistable magnetic wire is then detected by a sensing element. According to this invention, the magnetizing element and the bistable magnetic wire are maintained in a mutual position such that the magnitude of the magnetic field excited by the magnetizing element at the first end is different from the magnitude of the magnetic field excited by the magnetizing element at the second end. The definition of the difference in the magnitude of the magnetic fields at both ends should be explained by the fact that this difference applies in a stationary state, where the changing position of the bistable magnetic wire is not measured, even if the bistable magnetic wire can move relative to the magnetizing element (e.g., when measuring the pressure of a rotating tire). This means that at the moment of magnetization, both ends of the bistable magnetic wire are in magnetic fields of different magnitudes. When measuring the changing position of a bistable magnetic wire, for example when measuring a linear position, it is again true that at the moment of magnetization, the two ends of the bistable magnetic wire are in magnetic fields of different magnitudes, and at the same time, there is a difference in the magnetic fields due to the movement to be measured.

[0024] At the same time, it is preferred that the magnetic field has a triangular shape, particularly preferably a symmetrical triangular shape, and that the times of local maxima and minima of the response of the bistable magnetic wire are evaluated, which are essentially the times of magnetization of the bistable magnetic wire. The sum of these times is a parameter that describes the measured quantity and its position dependence, while other unmeasured factors and noise are suppressed. This improves the interpretability of the measurement data and speeds up the evaluation. It is also preferred that the difference of these times is calculated, and this parameter describes parasitic magnetic fields that interfere with the measurements of conventional magnetic sensors. The process according to the invention suppresses the influence of parasitic magnetic fields.

[0025] An important feature of both the system and the method according to the present invention is the fact that in the evaluation of the response signal, local maxima and minima are searched for and, after their recognition, the time T1, T2 at which these maxima and minima were measured is used. Furthermore, the method does not operate based on the value of the measured amplitude, as is common in the prior art, but on the value of time, which is an easily and clearly identifiable parameter in the received signal. This makes the evaluation fast, accurate, and less susceptible to various secondary effects. For example, the exact position, shape, and size of the excitation and sensing elements are not important.

[0026] In developing the subject matter of the present invention, it has been shown that bistable magnetic wires have different reactivity to different measurands depending on the frequency of the excitation field. Therefore, in a preferred configuration, the method according to the present invention includes exciting the magnetic field at different or variable frequencies depending on the type of measurand or position. Universal excitation generators, as well as excitation elements, can be optionally adapted for this, or different excitation elements can be used for different applications. Due to this discovery, one structure of bistable magnetic wire can also be used at different frequencies. The stable frequency value for one application may be different from the stable frequency used in another application, or these frequencies may be variable within different ranges for specific types of measurements.

[0027] An important advantage of the present invention is the repeatability of the measurements, which is related to an improved level of interpretation of the obtained raw data. A rapid response to changes in the measured physical quantity has also been demonstrated. The small dimensions, low cost, and energetically passive nature of the bistable magnetic wire allow the system according to the present invention to be used in a wide range of technical applications. [Brief explanation of the drawings]

[0028] The present invention will be explained in more detail using Figures 1 to 10. The particular sizes of the wires and excitation elements shown, and the values ​​of the measured quantities, are merely examples and should not be interpreted as narrowing the protection claimed by the present invention. [Figure 1] FIG. 1 is a block schematic diagram showing the structure of a bistable magnetic wire. [Figure 2] Figure 2 shows the bending stress measurement results of a steel bracket, with the left side showing the measurement results using a classic bistable magnetic wire of the prior art and the right side showing the measurement results using the bistable magnetic wire of the present invention. Figure 2 clarifies the technical problems solved in the prior art solutions. [Figure 3] FIG. 3 shows a schematic diagram of the position asymmetry of the excitation element relative to the bistable magnetic wire. [Figure 4] FIG. 4 is a schematic illustration of an asymmetrically wound coil of an excitation element. [Figure 5] Figure 5 shows the tension measurement system for the test tear samples. [Figure 6] FIG. 6 shows a schematic diagram of a system for measuring the temperature of the surface of a battery cell. [Figure 7] FIG. 7 then shows the dependence of the temperature course on the sum of the times T1+T2. [Figure 8] FIG. 8 is an oscilloscope screen showing the peak time values ​​aT1-T2 to cT1-cT2 when measuring temperature using three bistable magnetic wires. [Figure 9] FIG. 9 shows the coaxial position of the bistable magnetic wire relative to the excitation and sensing elements when measuring the linear position of the piston. [Figure 10] Figure 10 shows the magnetization of a bistable magnetic wire between two states when excited with a triangular signal. DETAILED DESCRIPTION OF THE INVENTION

[0029] Example 1

[0030] In this example, shown in Figures 3 and 5, a bistable magnetic wire 1 is used to measure tension or pressure in a steel part. The tear pattern has a calibrated central area and two clamping ends. A microwire with a metal core approximately 15 μm in diameter and a glass cover approximately 45 μm in total diameter and 3 cm in length is glued to the surface of the central area. In this example, the bistable magnetic wire 1 is oriented in the direction of the tensile force, so that the elongation of the steel material is transferred to the deformation of the bistable magnetic wire 1. A slight deviation in the mounting angle does not significantly affect the measurement accuracy. The bistable magnetic wire 1 is simultaneously aligned substantially in a straight line, with the first end 11 and the second end 12 positioned opposite each other. Therefore, the bistable magnetic wire 1 is not wound on a core, as is known from prior art applications.

[0031] An important feature of this embodiment is the use of position asymmetry to create asymmetry in the excitation field. The excitation element 2 is positioned next to the bistable magnetic wire 1, with its longitudinal axis substantially parallel to that of the bistable magnetic wire 1. The center of the coil of the excitation element 2 is shifted relative to the center of the bistable magnetic wire 1 by the value X, as shown in Figure 6. To minimize the distance between the excitation element 2 and the bistable magnetic wire 1, the longitudinal axes of the excitation element 2 and the bistable magnetic wire 1 are positioned so that they intersect a common plane passing through them, which is substantially perpendicular to the surface of the steel part. However, in principle, this measurement system is not affected by inaccuracies in the placement of the individual elements. All that matters is that the elongation of the material being measured is reliably transmitted to the bistable magnetic wire 1.

[0032] The positional asymmetry of the excitation element 2 results in the desired difference in magnetic field at the first end 11 and the second end 12, which, combined with the properties of the bistable magnetic wire 1, results in magnetization with a single Barkhausen jump from the first end 11 to the second end 12. The excitation element 2 generates a triangular signal magnetic field, the response of the bistable magnetic wire 1 is captured by the sensing element 3, which is connected to a control unit 4, where the response is evaluated.

[0033] The static and dynamic measurements are carried out on a tear machine. The signals obtained by the sensing element 3 are generally monotonic and have a high repeatability.

[0034] Example 2

[0035] For temperature measurement of a cylindrical battery cell according to Figures 6 and 7, a heat-sensitive bistable magnetic wire 1 is placed on the cell surface. The system also consists of a planar coil of the excitation element 2 and a small coil of the detection element 3. Measurements were performed in the temperature range from -20 to +100 °C.

[0036] The analog signal of two peaks (minimum and maximum) from the bistable magnetic wire 2 is monitored on an oscilloscope. The position times of the signal peaks T1 (maximum) and T2 (minimum) are processed in the control unit 4, converted into digital signals, and then displayed on a PC. The measured and evaluated signal shows an almost linear dependence between temperature and the magnetic response of the bistable magnetic wire 1, which is defined as the sum of the values ​​T1 + T2. The parameters of the detected dependence are then used to adjust the software parameters that display the actual temperature. In the case of a monotonic dependence, a calibration polynomial can be defined that is used to assign the raw data to the actual temperature. The sampling frequency is 2 samples / s, the sensitivity is 0.4 °C (K), and corresponds to 288 points of change at 120 °C intervals.

[0037] Using one excitation element 2 and one detection element 3, it is possible to build a system for measuring the temperature of multiple battery cells. As can be seen in Figure 9, the time positions of the signal peaks of three bistable magnetic wires 1 individually placed on three cylindrical battery cells can be clearly distinguished. The peaks are labeled aT1-aT2 through cT1-cT2. The signals received in this way can be clearly detected, resolved, and converted into the temperatures of the individual battery cells.

[0038] Example 3

[0039] A single bistable magnetic wire 1 connected to a moving piston is used for high-precision linear position measurement. In this example, the bistable magnetic wire 1 has the composition Fe 77.5 Si 7.5 B 15 It has positive magnetostriction, a length of 30 mm, a metal core diameter of 39 μm, and a diameter including the glass layer of 71 μm.

[0040] In this embodiment according to Fig. 9, the excitation element 2 and the sensing element 3 are formed by coils and loosely surround the sliding piston. The longitudinal axes of the excitation element 2, the sensing element 3 and the piston are the same. The bistable magnetic wire 1 is attached to the surface of the piston, so it only has a position approximately coaxial with the excitation element 2 and the sensing element 3, but this does not affect the accuracy of the position measurement.

[0041] The magnetic field asymmetry in this embodiment is achieved by positional asymmetry, such that at each position of the piston, the center of the bistable magnetic wire 1 is located outside the center of the excitation element 2. Furthermore, in this example, both ends 11, 12 are also located outside the center of the excitation element 2 at each position. In this way, the position of the excitation element 2 is set so that at the end positions of the piston, one end of the bistable magnetic wire 1 extends into the coil of the excitation element 2 but does not reach the center of the excitation element 2. The piston with the bistable magnetic wire 1 then extends further from inside the coil of the excitation element 2.

[0042] Unlike conventional position sensors where the position is defined by the magnetic permeability and the amplitude of the signal on the sensing coil, the system according to the present embodiment detects the magnetization of the bistable magnetic wire 1 which is proportional to the position.

[0043] A reliable induction method is used to detect magnetization. The excitation field has a triangular shape, and the switching time is measured. Here, T1 and T2 represent the magnetization time between two stable magnetic states (positive and negative switching) according to Figure 10. The switching time corresponds to the time when the maximum voltage is induced. The maximum and minimum values ​​of the received signal are clearly distinguishable, and the background does not affect the interpretability. The correctly amplified and filtered detected signal is connected to the digital input of a single-chip computer with a time resolution of within 10 ns. A simple electronic circuit in the control unit 4 is sufficient to achieve very high accuracy and measurement speed. The microcontroller's digital unit generates a PWM signal of the desired frequency (135 Hz in this example). After filtering and converting the received signal, the time T1 + T2 is summed by a timer.

[0044] The advantages of this system are the sharp maximum of the signal induced during magnetization and the high sensitivity at the level of 10 μm. In addition, the system is independent of the ambient temperature and the measurement error due to temperature sensitivity is less than 0.19%.

[0045] Example 4

[0046] 4, the coil of the excitation element 2 is wound unevenly with an increased number of threads at one end. At the same time, the bistable magnetic wire 1 is arranged such that, at a given time of non-zero excitation, the magnitude (amplitude) of the magnetic field excited by the excitation element 2 at the first end 11 differs from the magnitude (amplitude) of the magnetic field excited by the excitation element 2 at the second end 12 by at least 5%. [Industrial Applicability]

[0047] The industrial applicability is obvious: according to the invention, it is possible to repeatedly manufacture and use industrially the spatial and structural arrangement of the magnetizing elements and the bistable magnetic wire for measuring physical quantities and / or positions, in particular for measuring temperature, pressure, tension, magnetic field, current, position, earth magnetic field, torsion, linear position or angular position. [Explanation of symbols]

[0048] 1 - Bistable magnetic wire 11 - first end 12 - second end 2 - Excitation element 3 - Sensing element 4 - Control Unit T1 - Maximum signal response time T2 - Minimum signal response time

Claims

1. A system for measuring a physical quantity and / or a position using a bistable magnetic wire, comprising: a bistable magnetic wire (1); an excitation element (2) for generating a magnetic field within a range in which the bistable magnetic wire (1) is disposed; and a sensing element (3) for receiving a response from the bistable magnetic wire (1), wherein the bistable magnetic wire (1) has a first end (11) and a second end (12) disposed opposite the first end (11), and the magnetization is adjusted from the first end (11) to the second end (12) or vice versa by a single Barkhausen jump. A system for measuring physical quantities and / or positions using a bistable magnetic wire, characterized in that the excitation element (2) and the bistable magnetic wire (1) are arranged at a mutual position such that the amplitude of the magnetic field excited by the excitation element (2) at a first end (11) is different from the amplitude of the magnetic field excited by the excitation element (2) at a second end (12).

2. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire according to claim 1, characterized in that the difference in amplitude of the magnetic field at the first end (11) and the second end (12) is at least 5%.

3. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire according to claim 1, characterized in that it is adapted to measure temperature and / or pressure and / or tension and / or magnetic field and / or linear position.

4. 2. The system for measuring physical quantities and / or positions using bistable magnetic wires according to claim 1, characterized in that the coil of the receiving element (3) is separate from the coil of the exciting element (2).

5. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire according to claim 1, characterized in that the bistable magnetic wire (1) has a diameter of less than 50 μm.

6. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire according to claim 1, characterized in that the bistable magnetic wire (1) is covered with a layer of insulating material.

7. A system for measuring physical quantities and / or position using a bistable magnetic wire as described in claim 6, characterized in that the layer of insulating material is a layer of glass having a thickness of up to 20 μm.

8. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire according to claim 1, characterized in that the length of the bistable magnetic wire (1) is at least 1000 times the diameter of the metal core of the bistable magnetic wire (1).

9. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire according to claim 1, characterized in that the excitation element (2) is arranged asymmetrically with respect to the position of the bistable magnetic wire (1).

10. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire according to claim 1, characterized in that the excitation element (2) has an asymmetric structure with different magnetic field amplitudes at its ends.

11. 11. A system for measuring physical quantities and / or positions using a bistable magnetic wire as claimed in claim 10, characterized in that the excitation element (2) is formed by a coil having different winding densities at its first end (11) and its second end (12).

12. 2. A system for measuring physical quantities and / or positions using a bistable magnetic wire as claimed in claim 1, characterized in that the longitudinal axis of the excitation element (2) is the same as or parallel to the longitudinal axis of the bistable magnetic wire (1), or the longitudinal axis of the excitation element (2) is offset from the longitudinal axis of the bistable magnetic wire (1) by no more than 30 degrees.

13. A method for measuring a physical quantity and / or a position using a bistable magnetic wire, comprising: transmitting a variable magnetic field by an excitation element (2); placing at least one bistable magnetic wire (1) within the range of the excited magnetic field; and magnetizing the bistable magnetic wire (1) when the magnetic field changes from a first end (11) to a second end (12) of the bistable magnetic wire (1) or vice versa by a single Barkhausen front jump; and then detecting the response of the bistable magnetic wire (1) by a detection element (3). A method for measuring a physical quantity and / or a position using a bistable magnetic wire, characterized in that an excitation element (2) and a bistable magnetic wire (1) are maintained at mutual positions such that the amplitude of the magnetic field excited by the excitation element (2) at the first end (11) and the amplitude of the magnetic field excited by the excitation element (2) at the second end (12) are different.

14. 14. A method for measuring a physical quantity and / or a position using a bistable magnetic wire according to claim 13, characterized in that the excitation magnetic field has a waveform with a triangular magnitude, and the time T1 of the local maximum and the time T2 of the local minimum of the response of the bistable magnetic wire (1) are evaluated.

15. 14. A method for measuring a physical quantity and / or a position using a bistable magnetic wire as claimed in claim 13, characterized in that the excitation magnetic field has a frequency within a region in which the bistable magnetic wire (1) has at least one local maximum of sensitivity to a particular type of measurand or position.

16. 14. A method for measuring a physical quantity and / or a position using a bistable magnetic wire according to claim 13, characterized in that when evaluating the signal received as a response from the bistable magnetic wire (1), the sum of the time T1 of the local maximum value of the signal and the time T2 of the local minimum value is evaluated.

17. 17. A method for measuring a physical quantity and / or a position using a bistable magnetic wire as claimed in claim 16, characterized in that when evaluating the signal received as a response from the bistable magnetic wire (1), the difference between the time T2 of the local minimum and the time T1 of the local maximum of the signal is taken into account.

18. 14. A method for measuring a physical quantity and / or a position using a bistable magnetic wire according to claim 13, characterized in that the response of the bistable magnetic wire (1) intercepted in the sensing element (3) is evaluated in a control unit (4).

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