Test system and test method for magnetic shielding performance of magnetic thin strip

Abstract

This application discloses a testing system and method for the magnetic shielding performance of magnetic thin strips, belonging to the field of magnetic shielding performance testing technology. The testing system for the magnetic shielding performance of magnetic thin strips includes: a magnetic field generating device, a detection coil, and a first electrical detection device; the magnetic field generating device is used to emit a measuring magnetic field along the axial direction of the detection coil; the strip sample is adapted to be axially fitted outside the detection coil; the first electrical detection device is electrically connected to the detection coil; wherein, the first electrical detection device is configured to: acquire a first induced voltage of the detection coil when the strip sample is not fitted outside the detection coil; and acquire a second induced voltage of the detection coil when the strip sample is fitted outside the detection coil. This application can directly and quickly evaluate the magnetic shielding performance of magnetic thin strips.

Description

Technical Field

[0001] This application belongs to the field of magnetic shielding performance testing technology, and in particular relates to a testing system and testing method for the magnetic shielding performance of magnetic thin strips. Background Technology

[0002] With the rapid development of industries such as manufacturing, transportation, and electronics, the electromagnetic environment is becoming increasingly complex. In high-tech fields such as aerospace, precision measurement, and metrology, the requirements for the space electromagnetic environment are extremely stringent. Many precision instruments, such as traveling wave tubes and rubidium clocks on spacecraft, are highly susceptible to interference magnetic fields generated by components like magnetic torque converters during operation, leading to performance degradation or even failure. Therefore, using soft magnetic materials with high permeability for magnetic shielding of sensitive components is crucial.

[0003] However, current mainstream methods for testing magnetic shielding performance primarily target finished shielding structures that have already been manufactured, such as metal shielding enclosures or customized shielding covers. These methods require the shielding body to undergo a complete manufacturing process, resulting in lengthy testing cycles, high costs, and an inability to meet the real-time quality monitoring needs during material production. Particularly for raw materials like magnetic thin strips that are in the rolling, annealing, or heat treatment stages, there is a lack of an effective means to directly and quickly test their magnetic shielding performance. Summary of the Invention

[0004] This application aims to at least address the technical problems existing in the prior art where most magnetic shielding performance testing methods are designed for pre-formed shielding bodies, have long testing cycles and high costs, and cannot directly and quickly evaluate the performance of raw material strips in the rolling or heat treatment process.

[0005] In a first aspect, a testing system for the magnetic shielding performance of a magnetic thin strip includes: a magnetic field generating device, a detection coil, and a first electrical detection device; The magnetic field generating device is used to emit a measuring magnetic field along the axial direction of the detection coil; The strip sample is suitable for being axially sleeved outside the detection coil; The first electrical detection device is electrically connected to the detection coil; The first electrical detection device is configured to: acquire a first induced voltage of the detection coil when the strip sample is not covered outside the detection coil; and acquire a second induced voltage of the detection coil when the strip sample is covered outside the detection coil.

[0006] According to one embodiment of this application, the magnetic field generating device includes two Helmholtz coils; The detection coil is positioned between the two Helmholtz coils and is arranged parallel to the two Helmholtz coils.

[0007] According to one embodiment of this application, it further includes: a second electrical detection device and a functional signal generator; One of the Helmholtz coils is electrically connected to the function signal generator, the function signal generator is electrically connected to the second electrical detection device, and the second electrical detection device is electrically connected to the other Helmholtz coil; The second electrical detection device is configured to acquire the current value corresponding to the measured magnetic field.

[0008] According to one embodiment of this application, both the first electrical detection device and the second electrical detection device are digital multimeters.

[0009] According to one embodiment of this application, it further includes: a non-magnetic cylinder; The strip sample is sleeved around the outer periphery of the non-magnetic cylinder, and the non-magnetic cylinder is axially sleeved around the detection coil.

[0010] According to one embodiment of this application, it further includes: two first installation platforms and a second installation platform; The first installation platform is fixedly connected to each of the Helmholtz coils in a one-to-one correspondence; The second mounting platform is fixedly connected to the detection coil and the non-magnetic cylinder, and the detection coil is located at the center of the two Helmholtz coils and the non-magnetic cylinder.

[0011] Secondly, this application provides a method for testing the magnetic shielding performance of a magnetic thin strip, the method comprising: The magnetic field generator is controlled to emit a measuring magnetic field along the axial direction of the detection coil; Obtain the first induced voltage of the detection coil; With the strip sample sleeved along the axial direction of the detection coil, the second induced voltage of the detection coil is obtained; The shielding coefficient is determined based on the ratio of the first induced voltage to the second induced voltage.

[0012] According to one embodiment of this application, the step of sleeved the strip sample along the axial direction of the detection coil further includes: A non-magnetic cylinder is provided, and the strip sample is fitted onto the outer periphery of the non-magnetic cylinder, wherein one end of the strip sample is connected to the other end of the strip sample. The non-magnetic cylinder is axially sleeved outside the detection coil.

[0013] According to one embodiment of this application, the magnetic field generating device includes two Helmholtz coils; the detection coil is disposed between the two Helmholtz coils and is arranged parallel to the two Helmholtz coils; the detection coil is located at the center of the two Helmholtz coils.

[0014] According to one embodiment of this application, before the control magnetic field generating device emits a measuring magnetic field along the axial direction of the detection coil, the testing method further includes: Obtain the current value corresponding to the measured magnetic field; The measured magnetic field satisfies:

[0015] Where H is the magnetic field strength at the center of the Helmholtz coil; N is the number of turns of the Helmholtz coil; I is the current through the coil; and R is the radius of the Helmholtz coil.

[0016] In summary, this application includes at least one of the following beneficial technical effects: This application generates a measurement magnetic field using a magnetic field generator and acquires the induced voltage with and without a sample using a detection coil, thereby enabling a direct and rapid evaluation of the magnetic shielding performance of magnetic thin strips. This method avoids the problems of complex sample preparation, long testing cycles, and high costs in traditional testing, providing an effective means for evaluating the performance of raw material strips in high-tech fields such as aerospace and precision measurement.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of the testing system for the magnetic shielding performance of magnetic thin strip provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the non-magnetic cylinder provided in the embodiments of this application.

[0019] Figure label: 11. Helmholtz coil; 21. Detection coil; 31. First electrical detection device; 32. Second electrical detection device; 33. Functional signal generator; 41. Non-magnetic cylinder; 51. First installation platform; 52. Second installation platform. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] With the rapid evolution of modern industry, transportation, and the electronics and power industries, electromagnetic interference sources are becoming increasingly diversified and denser, significantly exacerbating the complexity of the electromagnetic environment. In critical fields such as aerospace, precision measuring instruments, metrology and calibration equipment, and high-end electronics manufacturing, the requirements for the purity of the electromagnetic environment are becoming increasingly stringent. For example, atomic clocks, quantum sensors, and core components of medical imaging equipment in spacecraft navigation systems are highly susceptible to stray magnetic field interference generated by surrounding magnetic torquers or other electronic devices during operation, leading to signal distortion, increased measurement deviations, or even complete malfunction. Therefore, employing high-permeability soft magnetic materials to effectively shield sensitive components has become a necessary measure to ensure stable equipment operation and data accuracy.

[0022] However, current mainstream methods for testing magnetic shielding performance primarily target finished shielding structures that have already been manufactured, such as metal shielding enclosures or customized shielding covers. These methods require the shielding body to undergo a complete manufacturing process, resulting in lengthy testing cycles, high costs, and an inability to meet the real-time quality monitoring needs during material production. Especially for raw materials like magnetic thin strips that are in the rolling, annealing, or heat treatment stages, existing technologies lack an effective means to directly and quickly test their magnetic shielding performance.

[0023] The following is for reference. Figure 1 and Figure 2 This application describes a testing system and method for testing the magnetic shielding performance of magnetic thin strips according to embodiments of the present application.

[0024] The testing system for the magnetic shielding performance of the magnetic thin strip includes: a magnetic field generating device, a detection coil 21, and a first electrical detection device 31; The magnetic field generator is used to emit a measuring magnetic field along the axial direction of the detection coil 21. This measuring magnetic field is a uniform magnetic field.

[0025] The strip sample is suitable for being axially sleeved outside the detection coil 21; The first electrical detection device 31 is electrically connected to the detection coil 21; The first electrical detection device 31 is configured to: acquire the first induced voltage of the detection coil 21 when no strip sample is placed outside the detection coil 21; and acquire the second induced voltage of the detection coil 21 when a strip sample is placed outside the detection coil 21.

[0026] The operator can manually operate the first electrical detection device 31 to perform two measurements with and without the strip sample, and record the corresponding induced voltage values; the shielding coefficient is determined by the ratio of the first induced voltage to the second induced voltage; the shielding coefficient can be determined by referring to the following formula.

[0027]

[0028] Where: U1—the induced voltage value of the detection coil 21 when no strip sample is placed outside the detection coil 21, in millivolts (mV); U2—the induced voltage value of the detection coil 21 when a strip sample is placed outside the detection coil 21, in millivolts (mV).

[0029] In the embodiments described above, a measurement magnetic field is generated by a magnetic field generator, and the induced voltage is obtained using a detection coil 21 with and without a sample, thereby enabling a direct and rapid evaluation of the magnetic shielding performance of the magnetic thin strip. This method avoids the problems of complex sample preparation, long testing cycles, and high costs in traditional testing, providing an effective means for performance evaluation of raw material strips in high-tech fields such as aerospace and precision measurement.

[0030] It should be noted that a measuring magnetic field is generated by a magnetic field generator, and the induced voltage is obtained using a detection coil 21 and a first electrical detection device 31 to evaluate the shielding performance. However, in actual operation, if the uniformity or stability of the measuring magnetic field generated by the magnetic field generator is insufficient, the induced voltage data obtained by the detection coil 21 may be inaccurate, thereby affecting the reliability of the magnetic shielding performance evaluation.

[0031] In some embodiments, the magnetic field generating device includes two Helmholtz coils 11; The detection coil 21 is positioned between the two Helmholtz coils 11 and is arranged parallel to the two Helmholtz coils 11.

[0032] Specifically, when current passes through the two Helmholtz coils 11, they generate a highly uniform and stable magnetic field in the central region. This uniform magnetic field ensures that the magnetic field environment of the probe coil 21 remains consistent throughout the test, avoiding measurement errors caused by magnetic field inhomogeneity. The size, number of turns, and current of the Helmholtz coil 11 can be designed and adjusted according to the required magnetic field strength and uniformity requirements. Furthermore, the probe coil 21 can be placed in the central region of the two Helmholtz coils 11, i.e., within the uniform magnetic field region, thereby making the first induced voltage obtained by the probe coil 21 without the strip sample and the second induced voltage obtained with the strip sample more accurate and reliable.

[0033] In some embodiments, the test system further includes: a second electrical detection device 32 and a functional signal generator 33; One Helmholtz coil 11 is electrically connected to the function signal generator 33, the function signal generator 33 is electrically connected to the second electrical detection device 32, and the second electrical detection device 32 is electrically connected to another Helmholtz coil 11. The second electrical detection device 32 is configured to acquire the current value corresponding to the measured magnetic field.

[0034] The following formulas can be used to measure the magnetic field H and the current value:

[0035] The magnetic field strength at the center of Helmholtz coil 11 is expressed in A / m; N is the number of turns of Helmholtz coil 11; I is the current flowing through the coil in A; and R is the radius of Helmholtz coil 11 in m. In this application, a functional signal generator 33 is used to generate the alternating current signal required to drive the Helmholtz coil 11. By adjusting the output parameters of the functional signal generator 33, the frequency and amplitude of the current applied to the Helmholtz coil 11 can be precisely controlled, thereby controlling the frequency and intensity of the measured magnetic field. The functional signal generator 33 can be a stand-alone laboratory signal source or a dedicated signal generation module integrated into a test system; its output can be amplified by a power amplifier to provide sufficient current to drive the Helmholtz coil 11.

[0036] In terms of electrical connection, the functional signal generator 33 acts as a power source, providing excitation current to one Helmholtz coil 11, thereby generating a magnetic field. The output of the functional signal generator 33 is connected in series with the input of the second electrical detection device 32, and the output of the second electrical detection device 32 is connected in series with the input of the other Helmholtz coil 11, thus forming a complete series circuit. This allows the current generated by the functional signal generator 33 to flow sequentially through the second electrical detection device 32 and the two Helmholtz coils 11. This series connection ensures that the second electrical detection device 32 can accurately measure the actual current flowing through the Helmholtz coil 11.

[0037] In actual implementation, both the first electrical detection device 31 and the second electrical detection device 32 are digital multimeters.

[0038] In some embodiments, the testing system further includes: a non-magnetic cylinder 41; The strip sample is fitted around the outer periphery of the non-magnetic cylinder 41, and the non-magnetic cylinder 41 is axially fitted around the detection coil 21.

[0039] The non-magnetic cylinder 41 is a cylindrical structure made of non-magnetic material. Its main function is to provide a stable support frame for the magnetic thin strip sample, ensuring that the sample maintains its preset geometric shape, such as a standard cylinder, during the test. Simultaneously, due to its non-magnetic properties, the non-magnetic cylinder 41 will not interfere with the measured magnetic field, thus ensuring the accuracy of the magnetic shielding performance test.

[0040] In some embodiments, the test system further includes: two first mounting platforms 51 and a second mounting platform 52; The first installation platform 51 is fixedly connected to the Helmholtz coil 11 in a one-to-one correspondence; The second mounting platform 52 is fixedly connected to the detection coil 21 and the non-magnetic cylinder 41. The detection coil 21 is set at the axial center of the two Helmholtz coils 11 and the non-magnetic cylinder 41.

[0041] In this embodiment, placing the probe coil 21 at the axial center of the two Helmholtz coils 11 ensures that the probe coil 21 is within the uniform magnetic field region generated by the Helmholtz coils 11, thereby improving measurement accuracy. Simultaneously, placing the probe coil 21 at the axial center of the non-magnetic cylinder ensures that the strip sample sleeved around the non-magnetic cylinder 41 can uniformly surround the probe coil 21, effectively avoiding measurement errors caused by eccentricity or asymmetry, thus improving the reliability of the magnetic shielding performance test.

[0042] The following description, in conjunction with the accompanying drawings, details the testing method for the magnetic shielding performance of magnetic thin strips provided in this application through specific embodiments and application scenarios.

[0043] The testing method for the magnetic shielding performance of magnetic thin strips can be applied to terminals, and can be executed by the hardware or software in the terminal.

[0044] The terminal includes, but is not limited to, portable communication devices such as mobile phones or tablets with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads). It should also be understood that, in some embodiments, the terminal may not be a portable communication device, but rather a desktop computer with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads).

[0045] The following embodiments describe a terminal including a display and a touch-sensitive surface. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, mouse, and joystick.

[0046] The testing method provided in this application embodiment can be executed by an electronic device or a functional module or entity in an electronic device that can implement the testing method. The electronic devices mentioned in this application embodiment include, but are not limited to, mobile phones, tablets, computers, cameras, and wearable devices. The testing method provided in this application embodiment is described below using an electronic device as the execution subject.

[0047] The testing method includes: S1. Control the magnetic field generating device to emit a measuring magnetic field along the axial direction of the detection coil 21; S2. Obtain the first induced voltage of the detection coil 21; S3. With a strip sample sleeved along the axial direction of the detection coil 21, obtain the second induced voltage of the detection coil 21; S4. Determine the shielding coefficient based on the ratio of the first induced voltage to the second induced voltage.

[0048] As one implementation method, the operator can manually operate the first electrical detection device 31 to perform two measurements with and without the strip sample, and record the corresponding induced voltage values; the shielding coefficient is determined by the ratio of the first induced voltage to the second induced voltage; the shielding coefficient can be referred to the following formula.

[0049]

[0050] When no strip sample is placed outside the probe coil 21, the induced voltage value of the probe coil 21 is measured in millivolts (mV); U2—when a strip sample is placed outside the probe coil 21, the induced voltage value of the probe coil 21 is measured in millivolts (mV).

[0051] By using the above technical solution, this application eliminates the step of manufacturing a shaped shield in traditional testing, enabling real-time performance evaluation of the raw material strip during rolling or heat treatment, significantly shortening the testing cycle, reducing testing costs, and ensuring the accuracy and reliability of the test results.

[0052] In some embodiments, a strip sample is sleeved along the axial direction of the detection coil 21, and the method further includes: A non-magnetic cylinder 41 is provided, and a strip sample is fitted onto the outer periphery of the non-magnetic cylinder 41, wherein one end of the strip sample is connected to the other end of the strip sample. The non-magnetic cylinder 41 is axially sleeved around the detection coil 21.

[0053] In this embodiment, when the strip sample is fitted onto the outer periphery of the non-magnetic cylinder 41, it is necessary to ensure that its surface fits tightly against the outer periphery of the non-magnetic cylinder 41 to avoid wrinkles, gaps, or looseness. One end of the strip sample can be connected to the other end of the strip sample by electrical tape or other means that can fix the strip sample, thereby avoiding gaps between the two ends of the strip sample, which would reduce the magnetic shielding effect.

[0054] It should also be noted that the area where one end of the strip sample connects to the other end of the strip sample should be small enough to avoid distortion of the measurement results.

[0055] In some embodiments, the magnetic field generating device includes two Helmholtz coils 11; a detection coil 21 is disposed between the two Helmholtz coils 11 and is arranged parallel to the two Helmholtz coils 11; the detection coil 21 is located at the center of the two Helmholtz coils 11.

[0056] In some embodiments, before the magnetic field generating device emits a measuring magnetic field along the axial direction of the detection coil 21, the test method further includes: Obtain the current value corresponding to the measured magnetic field; The measured magnetic field satisfies:

[0057] Where H is the magnetic field strength at the center of the Helmholtz coil 11; N is the number of turns of the Helmholtz coil 11; I is the current through the coil; and R is the radius of the Helmholtz coil 11.

[0058] The following example will provide a more detailed explanation of the above technical solution: This application further proposes a test method for the magnetic shielding performance of the aforementioned magnetic thin strip.

[0059] The test involves multiple magnetic fields with gradually increasing magnetic field strength. This application tests the magnetic shielding coefficient of a strip sample with grade BYR80 and a thickness of 0.145 mm under test magnetic fields of 40 A / m, 80 A / m, 160 A / m, 240 A / m, 320 A / m, 400 A / m, 480 A / m, 560 A / m, and 640 A / m.

[0060] In practice, the detection coil 21 is placed between the two Helmholtz coils 11 and parallel to the two Helmholtz coils 11, and the detection coil 21 is placed in the position of the uniform magnetic field at the center of the Helmholtz coil 11.

[0061] One of the Helmholtz coils 11 is electrically connected to the function signal generator 33, the function signal generator 33 is electrically connected to the second digital multimeter, the second digital multimeter is electrically connected to another Helmholtz coil 11, and the first digital multimeter is electrically connected to the detection coil 21.

[0062] Turn on the main power switch, turn on all instruments, and preheat for half an hour. Next, prepare the sample by taking a strip sample with a length of 140mm ± 2mm and a width of 102mm ± 2mm from the middle of the strip width along the rolling direction. The strip sample should be flat and free of defects such as burrs and cracks.

[0063] Next, the strip sample is rolled along the width direction to the outer periphery of the non-magnetic cylinder 41, and one end of the strip sample is connected to the other end of the strip sample with electrical tape or other means of fixing the sample, ensuring that there is no gap between the two ends of the strip sample. Then, the non-magnetic cylinder 41 is axially sleeved on the outside of the detection coil 21.

[0064] Subsequently, the function signal generator is adjusted so that the first digital multimeter displays that the current I corresponding to the measured magnetic field H at 40A / m is 87mA. At this time, the detection coil 21 generates an induced voltage, and the second digital multimeter displays that the induced voltage U1 is 17.2mV.

[0065] Then, the prepared sample was placed on the detection coil 21, ensuring that the detection coil 21 was centered on the non-magnetic cylinder 41. After the second digital multimeter stabilized, the induced voltage U2 of the detection coil 21 was recorded as 2.4mV. Finally, the experiment was completed, the sample was removed, and the magnetic shielding coefficient under this magnetic field was calculated to be 7.2. The magnetic shielding coefficients of the materials were repeatedly calculated and measured sequentially from low magnetic field to high magnetic field, resulting in Table 1 below.

[0066]

[0067] Table 1 Through the above technical solution, this application enables a comprehensive and systematic evaluation of the magnetic shielding performance of magnetic thin strips. By conducting tests under multiple gradually increasing magnetic field strengths, the magnetic shielding coefficient curves of the material under different magnetic field conditions can be obtained, thereby revealing the law of its magnetic shielding performance changing with the magnetic field. This is crucial for accurately selecting and optimizing the use of magnetic shielding materials in various application scenarios.

[0068] In some embodiments, this application also provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the program is executed by the processor, it implements the various processes of the above-described test method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0069] It should be noted that the electronic devices in the embodiments of this application include the aforementioned mobile electronic devices and non-mobile electronic devices.

[0070] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described test method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0071] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0072] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described testing method.

[0073] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0074] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described test method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0075] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0076] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0077] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0078] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0079] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A system for testing the magnetic shielding effectiveness of a magnetic ribbon, comprising: a magnetic field generator; a magnetic field sensor; a magnetic ribbon; and a test fixture for holding the magnetic ribbon in a position to be tested. include: Magnetic field generating device, detection coil, and first electrical detection device; The magnetic field generating device is used to emit a measuring magnetic field along the axial direction of the detection coil; The strip sample is suitable for being axially sleeved outside the detection coil; The first electrical detection device is electrically connected to the detection coil; The first electrical detection device is configured to: acquire a first induced voltage of the detection coil when the strip sample is not covered outside the detection coil; and acquire a second induced voltage of the detection coil when the strip sample is covered outside the detection coil.

2. The system for testing magnetic shielding performance of magnetic strip of claim 1, wherein, The magnetic field generating device includes two Helmholtz coils; The detection coil is positioned between the two Helmholtz coils and is arranged parallel to the two Helmholtz coils.

3. The system for testing magnetic shielding effectiveness of magnetic ribbon according to claim 2, wherein, It also includes: a second electrical detection device and a function signal generator; One of the Helmholtz coils is electrically connected to the function signal generator, the function signal generator is electrically connected to the second electrical detection device, and the second electrical detection device is electrically connected to the other Helmholtz coil; The second electrical detection device is configured to acquire the current value corresponding to the measured magnetic field.

4. The system for testing magnetic shielding effectiveness of magnetic ribbon of claim 3, wherein, Both the first electrical detection device and the second electrical detection device are digital multimeters.

5. The system for testing magnetic shielding effectiveness of magnetic ribbon of claim 2, wherein, Also includes: Non-magnetic cylinder; The strip sample is sleeved around the outer periphery of the non-magnetic cylinder, and the non-magnetic cylinder is axially sleeved around the detection coil.

6. The system for testing magnetic shielding performance of magnetic thin strips according to claim 5, wherein, Also includes: Two primary installation platforms and a secondary installation platform; The first installation platform is fixedly connected to each of the Helmholtz coils in a one-to-one correspondence; The second mounting platform is fixedly connected to the detection coil and the non-magnetic cylinder, and the detection coil is set at the axial center of the two Helmholtz coils and the non-magnetic cylinder.

7. A method of testing the magnetic shielding effectiveness of a magnetic ribbon, characterized by, include: The magnetic field generator is controlled to emit a measuring magnetic field along the axial direction of the detection coil; Obtain the first induced voltage of the detection coil; With the strip sample sleeved along the axial direction of the detection coil, the second induced voltage of the detection coil is obtained; The shielding coefficient is determined based on the ratio of the first induced voltage to the second induced voltage.

8. The method of claim 7, wherein the magnetic shielding performance of the magnetic thin strip is measured by using a magnetic field sensor. The step of sleeved the strip sample along the axial direction of the detection coil further includes: A non-magnetic cylinder is provided, and the strip sample is fitted onto the outer periphery of the non-magnetic cylinder, wherein one end of the strip sample is connected to the other end of the strip sample. The non-magnetic cylinder is axially sleeved outside the detection coil.

9. The method of claim 7, wherein the magnetic shielding performance of the magnetic thin strip is measured by using a magnetic field sensor. The magnetic field generating device includes two Helmholtz coils; the detection coil is disposed between the two Helmholtz coils and is arranged parallel to the two Helmholtz coils; the detection coil is located at the center of the two Helmholtz coils.

10. The method of claim 7, wherein the magnetic shielding performance of the magnetic thin strip is measured by using a magnetic field sensor. Before the control magnetic field generating device emits a measuring magnetic field along the axial direction of the detection coil, the test method further includes: Obtain the current value corresponding to the measured magnetic field; The measured magnetic field satisfies: Where H is the magnetic field strength at the center of the Helmholtz coil; N is the number of turns of the Helmholtz coil; I is the current through the coil; and R is the radius of the Helmholtz coil.

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