Magnetic detection method and device

Abstract

The invention provides a magnetic detection method and device, and the method comprises the steps: S1, installing a to-be-detected sample in a sample cup, and fixing the sample cup on a sample rod and detection equipment; s2, starting the vibration of the sample rod, adjusting the four-dimensional space position of the sample based on the target detection magnetic characteristics of the to-be-detected sample, the four-dimensional space position movement capability of the sample rod and the coil structure and magnetic field distribution direction of the detection equipment, observing the change of the magnetic signal, and determining the target detection position; s3, positioning a to-be-detected sample at a target detection position, and performing magnetic curve detection on the to-be-detected sample to obtain a target position magnetic detection curve; s4, based on the target position magnetic detection curve, directly extracting target detection magnetic features; or a correction factor is obtained through calculation based on the target position magnetic detection curve, and after the correction factor is used for correcting the magnetic detection curve collected at the non-target detection position, the target detection magnetic characteristics are extracted. Therefore, the measurement accuracy can be improved, and the method can adapt to various application scenes.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of detection, and particularly relates to a magnetic detection method and device. BACKGROUND

[0002] There are many kinds of magnetic materials, including diamagnetic materials, paramagnetic materials, soft magnetic materials, permanent magnetic materials, spin electronic materials, multi-layer film materials, isotropic materials, anisotropic materials, single crystal materials, polycrystalline materials, nanomaterials, composite materials, etc. At present, magnetic materials are widely used in generators, transformer cores, data storage, medical imaging equipment, etc. They have become the cornerstone of modern industry and have penetrated into many key fields such as modern energy, information, transportation and medical treatment. The performance of magnetic materials directly determines the efficiency and boundary of technical equipment. Accurate evaluation of key parameters such as saturation magnetization, coercivity, maximum permeability, remanence and maximum magnetic energy product of magnetic materials is an important means to ensure that materials meet strict design requirements, find internal defects and fatigue damage through non-destructive methods, and effectively prevent major accidents caused by material failure. Therefore, accurate detection of the magnetic properties of magnetic materials is an invisible pillar supporting the stable development of modern science and technology and industrial system.

[0003] Magnetic materials can be mainly divided into bulk materials, thin strip and film materials, powder materials, liquid materials, etc. according to their shape characteristics. Many magnetic detection devices can only detect regular bulk materials, but cannot detect thin strips, powders, liquids, etc. For example, high-coercivity pulsed magnetic field devices, magnetic powder flaw detectors, permanent magnet measuring instruments, etc. The vibrating sample magnetometer is widely used in the field of magnetic detection because of its strong shape inclusiveness for magnetic samples (not only bulk materials but also thin strip and film materials, powder materials, liquid materials, needle-shaped materials, porous materials, irregularly shaped materials, etc.) and high detection sensitivity.

[0004] The conventional method for magnetic detection by using a vibrating sample magnetometer is as follows: after the sample mass is weighed and the device is calibrated and performance verified by using a standard sample, the sample to be detected is fixed to the sample cup, sample rod and detection device, and then a magnetic curve detection is performed by selecting a setting program. However, it is found in actual detection that the magnetic measurement values (such as saturation magnetization, remanence, magnetic permeability, maximum magnetic energy product, etc.) of the same sample often have large magnetic test deviation and low test data accuracy under different vibrating sample magnetometer device conditions or even under the same vibrating sample magnetometer device condition. To solve this problem, the existing technology usually adopts a multiple repeated detection method (including repeated detection of the same sample or parallel detection of different samples) or uses a parallel standard sample with consistent external size as an auxiliary detection means. However, the multiple repeated detection method significantly increases the test task amount and reduces the detection efficiency, and the improvement effect on data accuracy easily fluctuates with the sample size scene. The parallel standard sample method has many limitations: it involves special preparation of the parallel standard sample and has poor operation convenience, is limited to regular block materials with easily controlled external size, cannot be adapted to scenarios of film materials, powder materials and irregular materials with difficultly controlled external size, and has strict requirements on the structural uniformity of the sample. Therefore, how to simply and effectively solve the problems of large magnetic test deviation, low test data accuracy and difficult detection method to adapt to various scenes is still an important issue to be broken through in the field of magnetic detection. SUMMARY

[0005] The present disclosure provides a magnetic detection method and device to simply and effectively solve the problems of large magnetic measurement value deviation, low test data accuracy and difficult adaptation to various application scenarios.

[0006] According to one aspect of the present disclosure, a magnetic detection method is provided, which comprises: S1: installing a sample to be detected to a sample cup and fixing the sample cup to a sample rod and a detection device; S2: starting vibration of the sample rod, and based on a target detection magnetic feature of the sample to be detected, four-dimensional space movement capability of the sample rod and coil structure and magnetic field distribution direction of the detection device, adjusting the four-dimensional space position of the sample, observing the magnetic signal change and determining a target detection position; the target detection position is a position at which the magnetic signal change rate is the smallest when the sample to be detected is displaced in the magnetic field area of the detection device; S3: positioning the sample to be detected at the target detection position, performing magnetic curve detection on the sample to be detected and obtaining a target position magnetic detection curve; S4: directly extracting the target detection magnetic feature based on the target position magnetic detection curve, or calculating a correction factor based on the target position magnetic detection curve, correcting the magnetic detection curve collected at a non-target detection position by using the correction factor and then extracting the target detection magnetic feature.

[0007] In addition, according to the method of one aspect of the present disclosure, the sample to be detected includes, but is not limited to, a regular-shaped sample, an irregular-shaped sample, a solid sample, a fluid sample and a powder sample, a needle-shaped material, a porous material, etc.; the sample to be detected is a magnetic material under normal temperature and high-low temperature conditions. The measurable magnetic material includes, but is not limited to, a diamagnetic material, a paramagnetic material, a soft magnetic material, a permanent magnetic material, a spin electronic material, a multi-layer film material, an isotropic material, an anisotropic material, a single crystal material, a polycrystalline material, a nano material, a composite material, etc.

[0008] In addition, according to the method of one aspect of the present disclosure, the target detection magnetic feature includes, but is not limited to, at least one of the following magnetic curves or magnetic parameters: a hysteresis loop, an initial magnetization curve, a demagnetization curve, a minor hysteresis curve, a direct current remanence curve, an alternating current remanence curve, a magnetization time function curve, a magnetization temperature function curve, a first-order reversal curve FORC, a turning angle experiment curve, a saturation magnetization, a remanence, a coercivity, an intrinsic coercivity, a maximum magnetic energy product, a saturation magnetic field, a maximum permeability, an initial permeability, a recovery permeability, a squareness; the test temperature condition of the magnetic curve or the magnetic parameter is one or a combination of room temperature constant temperature, low temperature constant temperature, high temperature constant temperature or variable temperature; the four-dimensional space position moving ability includes: an X-axis direction moving ability, a Y-axis direction moving ability, a Z-axis direction moving ability and a rotating ability; the magnetic field distribution direction includes: a parallel direction of the magnetic field direction and the ground and a vertical direction of the magnetic field direction and the ground; the X-axis direction, the Y-axis direction and the Z-axis direction are three-dimensional coordinate system directions, and the X-axis direction is a parallel magnetic field direction, and the Y-axis direction and the Z-axis direction are vertical magnetic field directions.

[0009] In addition, according to the method of one aspect of the present disclosure, the sample rod is excited, and based on the target detection magnetic feature of the sample to be detected, the four-dimensional space position moving ability of the sample rod and the coil structure and the magnetic field distribution characteristic of the detection equipment, the four-dimensional space position of the sample is adjusted, the magnetic signal change is observed, and the target detection position is determined, including: at least one of the following ways is adopted: the detection equipment is used to apply an external magnetic field to the sample to be detected or the sample to be detected is initially magnetized, and an external equipment is used to magnetize the sample to be detected in a stable magnetization state in the detection direction; the stable magnetization state is used to indicate that the magnetic substance in the sample to be detected has been magnetized, and the magnetic signal is stable, and the magnetic signal change is easy to identify; the sample rod is moved in the four-dimensional space by means of the detection equipment, and the movement of the sample rod is cooperatively adjusted with the fixed direction and / or fixed position of the sample to be detected on the sample cup and the sample rod, so as to realize the movement of the sample to be detected in the four-dimensional space position; during the movement of the sample to be detected in the four-dimensional space position, the change of the magnetic signal strength is observed, and when the changes of the rotating direction, the X-axis direction, the Y-axis direction and the Z-axis direction with the position change are the smallest, the target detection position is determined.

[0010] In addition, according to the method of one aspect of the present disclosure, the sample to be detected is positioned at a target detection position, and magnetic curve detection is performed on the sample to be detected to obtain a target position magnetic detection curve, including: when the sample to be detected is moved to be positioned at the target detection position, starting a coil driving module of the detection device, applying an external magnetic field to the sample to be detected according to a preset magnetic field strength gradient program, and collecting a magnetic response signal of the sample to be detected; determining a target position magnetic detection curve with the magnetic response signal M as the longitudinal coordinate and the magnetic field strength H, time t, or temperature T as the transverse coordinate.

[0011] In addition, according to the method of one aspect of the present disclosure, the target detection magnetic feature is directly extracted, including: directly extracting original data points corresponding to the magnetic response signal M, the magnetic field strength H, the time t, and the temperature T in the magnetic detection curve obtained in the magnetic detection process as the target detection magnetic feature, or first performing mathematical operation on the magnetic detection curve according to a preset formula relationship and then directly extracting the target detection magnetic feature.

[0012] In addition, according to the method of one aspect of the present disclosure, a correction factor is obtained based on the target position magnetic detection curve, and the target detection magnetic feature is extracted after the magnetic detection curve collected at the non-target detection position is corrected using the correction factor, including: selecting a magnetic field strength, and determining the ratio of the magnetic response signal of the target position magnetic detection curve to the magnetic response signal of the non-target detection position magnetic detection curve for the selected magnetic field strength, and determining the average or weighted average of the ratio as the correction factor; multiplying the magnetic response signal corresponding to the non-target detection position magnetic detection curve by the correction factor to obtain a corrected magnetic detection curve; and extracting and determining the target detection feature based on the corrected magnetic detection curve.

[0013] In addition, according to the method of one aspect of the present disclosure, the method further includes: correcting the detection device using a standard sample.

[0014] According to another aspect of the present disclosure, a magnetic detection device is provided, the device comprising: a fixing unit for mounting a sample to be detected to a sample cup and fixing the sample cup to a sample rod of a detection apparatus and the detection apparatus; a determining unit for starting vibration of the sample rod and adjusting a four-dimensional spatial position of the sample based on a target detection magnetic feature of the sample to be detected, a four-dimensional spatial movement capability of the sample rod, and a coil structure and a magnetic field distribution direction of the detection apparatus, observing a magnetic signal change, and determining a target detection position; the target detection position being a position at which a magnetic signal change rate is minimum when the sample to be detected changes position in a magnetic field region of the detection apparatus; an acquiring unit for positioning the sample to be detected at the target detection position and performing magnetic curve detection on the sample to be detected to obtain a target position magnetic detection curve; and an extracting unit for directly extracting the target detection magnetic feature based on the target position magnetic detection curve or calculating a correction factor based on the target position magnetic detection curve, correcting a magnetic detection curve collected at a non-target detection position using the correction factor, and extracting the target detection magnetic feature.

[0015] The present disclosure provides a magnetic detection method and device. The present disclosure comprises the following steps: S1: mounting a sample to be detected to a sample cup and fixing the sample cup to a sample rod of a detection apparatus and the detection apparatus; S2: starting vibration of the sample rod and adjusting a four-dimensional spatial position of the sample based on a target detection magnetic feature of the sample to be detected, a four-dimensional spatial movement capability of the sample rod, and a coil structure and a magnetic field distribution direction of the detection apparatus, observing a magnetic signal change, and determining a target detection position; the target detection position being a position at which a magnetic signal change rate is minimum when the sample to be detected changes position in a magnetic field region of the detection apparatus; S3: positioning the sample to be detected at the target detection position and performing magnetic curve detection on the sample to be detected to obtain a target position magnetic detection curve; S4: directly extracting the target detection magnetic feature based on the target position magnetic detection curve or calculating a correction factor based on the target position magnetic detection curve, correcting a magnetic detection curve collected at a non-target detection position using the correction factor, and extracting the target detection magnetic feature. In this way, compared with the existing method of multiple measurements or relying on multiple parallel standards to eliminate errors in the measurement of a vibrating sample magnetometer, the present disclosure can reduce signal fluctuation interference caused by sample displacement from the source by positioning the target detection position at which the magnetic signal change rate is minimum, and even if there is an initial positioning error of the sample or individual differences in the morphological features and structural uniformity of the sample, the influence of such factors on the detection result can be reduced through accurate position adjustment. Meanwhile, the introduction and flexible application of the correction factor can effectively correct the detection data at the non-target position, thereby improving the reliability of the extraction of the magnetic feature at the non-target position under the influence of human operation deviation or hardware condition limitation. In summary, the technical solution provided by the present disclosure can effectively solve the limitations of the existing multiple measurement or multiple parallel standard measurement method, ensure detection accuracy, expand application scenarios, and improve measurement accuracy, and can be adapted to various application scenarios.

[0016] It is to be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further explanation of the subject technology claimed. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[0018] Figure 1 A flowchart of a magnetic detection method provided by an embodiment of the present disclosure;

[0019] Figure 2 A schematic diagram of a three-dimensional target detection position provided by an embodiment of the present disclosure;

[0020] Figure 3 A curve schematic diagram of a three-dimensional target detection position provided by an embodiment of the present disclosure;

[0021] Figure 4 A curve schematic diagram of a two-dimensional target detection position provided by an embodiment of the present disclosure;

[0022] Figure 5 A structural block diagram of a magnetic detection device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] In order to make the objects, technical solutions and advantages of the present disclosure more apparent, the following will describe the example embodiments according to the present disclosure in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited by the example embodiments described herein.

[0024] At present, when the magnetic detection of magnetic materials is performed, many use a vibrating sample magnetometer for measurement. However, when the vibrating sample magnetometer is used for measurement, it may cause the problems of large deviation of the magnetic measurement value of the same sample and low accuracy of the test data due to at least one factor of the shape characteristics, internal structure uniformity, etc. of the magnetic material itself, and is difficult to adapt to various application scenarios.

[0025] Therefore, in order to solve the above problems, the present disclosure provides a magnetic detection method. The present disclosure can reduce the signal fluctuation interference caused by sample displacement from the source by positioning the target detection position with the minimum magnetic signal change rate. Even if the initial positioning of the sample has deviations or individual differences in the morphological characteristics and structural uniformity of the sample, the influence of these factors on the detection results can be reduced through accurate position adjustment. At the same time, combined with the introduction and flexible application of the correction factor, the non-target position detection data can be effectively corrected, and the reliability of magnetic feature extraction at non-target position detection under the condition of human operation deviation or hardware condition limitation can be simultaneously improved.

[0026] The present disclosure provides a magnetic detection method. Please refer to Figure 1 , Figure 1 A flowchart of a magnetic detection method provided by an embodiment of the present disclosure is shown in FIG. 1. As shown in FIG. 1, the method comprises the following steps. Figure 1

[0027] S1: installing a sample to be detected into a sample cup, and fixing the sample cup on a sample rod and a detection device;

[0028] S2: starting the sample rod, and based on a target detection magnetic feature of the sample to be detected, a four-dimensional space position moving ability of the sample rod, and a coil structure and a magnetic field distribution direction of the detection device, adjusting the four-dimensional space position of the sample, observing the magnetic signal change, and determining the target detection position; the target detection position is a position with the minimum magnetic signal change rate when the sample to be detected is displaced in the magnetic field area of the detection device;

[0029] S3: positioning the sample to be detected at the target detection position, and performing magnetic curve detection on the sample to be detected to obtain a target position magnetic detection curve;

[0030] S4: directly extracting the target detection magnetic feature based on the target position magnetic detection curve; or calculating a correction factor based on the target position magnetic detection curve, and extracting the target detection magnetic feature after correcting the magnetic detection curve collected at a non-target detection position by using the correction factor.

[0031] In the present disclosure, the detection device can be understood as an integrated instrument with functions of magnetic field generation, magnetic signal collection, sample posture control, and data processing, which can realize sample position adjustment and accurate capture of magnetic signals. The device can flexibly adjust the magnetic field strength, magnetization intensity detection range, magnetic curve data point sampling requirements, and other functions according to the detection requirements, and the specific implementation is not limited.

[0032] In the present disclosure, the sample cup can be understood as a special container for carrying and fixing the sample to be detected.

[0033] ​In this disclosure, the sample rod can be understood as a core transmission component connecting the sample cup and the drive mechanism of the detection equipment. It has multiple functions, including carrying the sample, assisting in or independently realizing the four-dimensional spatial movement of the sample to be tested, and driving the sample to vibrate at high frequency in a magnetic field. The sample rod can be detachably connected to the sample cup via threads or a quick-release structure.

[0034] In this disclosure, the target detection magnetic feature can be understood as a magnetic curve or magnetic parameter that reflects the essential magnetic properties of the sample to be detected. The target detection magnetic feature of this disclosure may include, but is not limited to, at least one of the following magnetic curves or magnetic parameters: hysteresis loop, initial magnetization curve, demagnetization curve, small hysteresis curve, DC remanence curve, AC remanence curve, magnetization intensity time function curve, magnetization intensity temperature function curve, first-order reversal curve FORC, rotation angle test curve, saturation magnetization, remanence, coercivity, intrinsic coercivity, maximum energy product, saturation magnetic field, maximum permeability, initial permeability, recovered permeability, squareness; the test temperature conditions for the magnetic curve or magnetic parameter are one or a combination of room temperature isothermal, low temperature isothermal, high temperature isothermal, or variable temperature. Among them, the hysteresis loop, as the most fundamental magnetic characteristic curve, fully presents the closed-loop process of the sample's magnetization intensity changing with the external magnetic field, and its shape can directly distinguish between soft and hard magnetic materials. The initial magnetization curve records the change law of magnetization intensity with the increase of the external magnetic field from the sample's complete demagnetization state. The demagnetization curve, as the second quadrant part of the hysteresis loop, is closely related to parameters such as intrinsic coercivity and remanence, and is of great significance for the detection of permanent magnet targets. The first-order flip curve FORC has a more refined advantage than conventional magnetic curves. By controlling the continuous flipping of the magnetic field and the acquisition of magnetization response, it can effectively analyze the interaction of magnetic domains inside the sample. The distribution characteristics are analyzed; the angle-shifting experimental curves focus on the anisotropy of the sample's magnetism, obtaining differences in magnetization response by changing the relative angle between the magnetic field and the sample; the magnetization intensity time function curve and temperature function curve reveal the variation of the sample's magnetism with time and temperature, respectively; saturation magnetization is the maximum magnetization intensity that a magnetic material can achieve when magnetized in an applied magnetic field, and it is an extremely important magnetic parameter for ferromagnetic materials; coercivity and intrinsic coercivity together characterize the sample's ability to resist demagnetization; the maximum energy product is one of the key indicators for evaluating the performance of permanent magnet materials, and its value determines the magnetic field output capability of permanent magnet targets in practical applications. Squareness, as a parameter describing the rectangularity of the hysteresis loop, has a clear direction for target detection in fields such as permanent magnet materials, magnetic recording, and sensors. Meanwhile, the selection of test temperature conditions must be closely combined with the application scenario and magnetic properties of the sample to be tested: room temperature isothermal testing is suitable for target detection under normal environments, ensuring the universality and comparability of data; low temperature isothermal testing involves placing the sample in a constant low temperature environment (such as 5K, 77K), maintaining the temperature constant, and measuring the magnetic curve to focus on the magnetic characteristics at specific low temperatures; high temperature isothermal testing measures the magnetic curve in a constant high temperature environment, focusing on the performance at specific high temperatures; variable temperature testing involves continuously changing the temperature from low to high or high to low, simultaneously measuring the magnetic curve to obtain the curve of magnetic properties changing with temperature. Low temperature isothermal testing, high temperature isothermal testing, and variable temperature testing all serve to explore the influence of temperature on the magnetic characteristics of magnetic materials.

[0035] In this disclosure, the four-dimensional spatial movement capability of the sample rod can be understood as the combined movement capability of the sample rod driving the sample to achieve three-dimensional translation and one-dimensional rotation in space. Through the independent action of this capability or its synergistic effect with the sample movement capability, the sample can be precisely adjusted to any position in the magnetic field. The four-dimensional spatial position movement capability of the sample rod in this disclosure includes: movement capability in the X-axis direction, movement capability in the Y-axis direction, movement capability in the Z-axis direction, and rotation capability. The X-axis direction, Y-axis direction, and Z-axis direction are directions in the three-dimensional coordinate system, and the X-axis direction is parallel to the magnetic field direction, while the Y-axis direction and Z-axis direction are perpendicular to the magnetic field direction. In this disclosure, the coil structure of the detection device can be understood as a combination of components used to generate the magnetic field required for detection. It can be composed of multiple coils with different functions arranged in a specific spatial layout, including but not limited to Helmholtz coils, copper coils, superconducting coils for generating a uniform DC magnetic field, saddle-shaped coils for superimposing AC magnetic fields, and shielding coils for compensating for stray magnetic fields.

[0036] In this disclosure, the magnetic field distribution direction of the detection device can be understood as the spatial orientation of the magnetic field intensity vector within the detection area. The magnetic field distribution directions in this disclosure include: a magnetic field direction parallel to the ground and a magnetic field direction perpendicular to the ground. In detection devices where the magnetic field direction is parallel to the ground, the sample rod typically possesses full four-dimensional spatial movement capability. This characteristic allows such devices to determine the target detection position of the sample without generally requiring coordinated operation with the sample movement capability; the sample attitude adjustment can be completed solely by moving the sample rod. Therefore, the method for adjusting the target position is significantly simpler and more convenient. However, for detection devices where the magnetic field direction is perpendicular to the ground, the sample rod typically only possesses X-axis movement capability and lacks full four-dimensional spatial movement capability. Yet, the maximum magnetic field strength of these devices often reaches 4-9T. Therefore, determining the target position often requires coordinated adjustment with the sample movement capability, resulting in relatively less ease of operation in the target detection position determination process. However, these devices, with their higher magnetic field strength, are more suitable for magnetic feature detection scenarios with high requirements for magnetic field strength.

[0037] In this disclosure, the target detection position can be understood as the optimal detection point within the effective magnetic field area of ​​the detection device that minimizes the interference of sample displacement on the magnetic signal. The core feature of this position is that the rate of change of the magnetic signal collected by the magnetic sensor is at its minimum during the vibration or slight displacement of the sample.

[0038] In this disclosure, the target position magnetic detection curve can be understood as the relationship curve between the magnetic response signal M and the magnetic field strength H, the magnetic response signal M and the detection time t, or the magnetization response signal M and the detection temperature T when the sample to be detected is at the target detection position and the magnetic field strength changes.

[0039] In this disclosure, the correction factor can be understood as a coefficient constructed based on the magnetic detection curve of the target position to correct the deviation of the detection data of the non-target position. Its core function is to reduce the systematic error introduced by the detection position deviating from the optimal value.

[0040] In this disclosure, the X-axis movement is mainly used to adjust the position of the sample along the magnetic field direction in the horizontal plane, with an adjustment accuracy that can even reach the micrometer level, and is used to align the sample center with a uniform region of the magnetic field distribution direction; the Y-axis and Z-axis movements are used to adjust the spatial position of the sample in the direction perpendicular to the magnetic field; the rotation capability allows the sample to rotate around its own central axis, which can be used to eliminate the angular deviation between the sample's detection direction (such as the magnetization direction, crystal orientation direction, specific geometric dimension direction, etc.) and the magnetic field direction caused by installation deviations of the sample on the sample rod and detection equipment. It can also be used to adjust the angle between the sample's magnetization geometry direction and the magnetic field direction as needed, thereby realizing the detection of magnetic characteristics in different directions and meeting the detection requirements of anisotropic magnetic materials.

[0041] Specifically, the magnetic detection process can be performed as follows: First, select a suitable sample cup according to the shape of the sample to be tested and the testing requirements. Fix the sample onto the sample cup and ensure a secure installation. Then, install the sample cup onto the connection interface of the sample rod. Next, install the sample rod onto the testing equipment to complete sample loading. Then, activate the equipment's vibration function, causing the sample rod to drive the sample to vibrate at a preset frequency and amplitude. Apply an external magnetic field to the sample using the testing equipment, or utilize at least one of the following methods: initially magnetizing the sample or using external equipment for magnetization. This ensures the sample is in a stable magnetic state in the testing direction. A stable magnetic state indicates that the magnetic material within the sample has been magnetized, and the magnetic signal is stable and easily identifiable when it changes. Afterward, by coordinating the movement of the sample rod with the fixed direction and / or fixed position of the sample on the sample cup and sample rod, the sample is subjected to four-dimensional spatial rotation in the X, Y, Z axes and rotational direction. The magnetic sensor adjusts its position and orientation during this process, acquiring magnetic signal data in real time. The acquired signals are tracked in real time, allowing observation of changes in the magnetic signal of the sample under different four-dimensional spatial positions. The position with the smallest rate of change in magnetic signal is then identified as the target detection position. Subsequently, the sample is stabilized at the target detection position, and a magnetic field scanning program is initiated. The coil current is adjusted according to a preset magnetic field strength gradient, and the magnetization data of the sample is acquired simultaneously to generate a magnetic detection curve for the target position. Finally, if only the core magnetic features are needed, magnetic parameters (such as remanence and intrinsic coercivity) can be directly extracted from the magnetic detection curve at the target position using a curve analysis algorithm. If there is detection data at non-target positions or batch detection is required, a correction factor can be calculated based on the difference between the magnetic detection curve at the target position and the curve at the non-target position. This factor is used to correct the non-target position data before extracting the accurate target detection magnetic features, completing the entire magnetic detection process.

[0042] The following will describe in detail the specific contents of the samples to be tested, including but not limited to samples with regular shapes, irregular shapes, solid samples, fluid samples, powder samples, needle-like materials, porous materials, etc.; the samples to be tested are magnetic materials under room temperature and high / low temperature conditions. Measurable magnetic materials include, but are not limited to, diamagnetic materials, paramagnetic materials, soft magnetic materials, permanent magnet materials, spintronic materials, multilayer film materials, isotropic materials, anisotropic materials, single-crystal materials, polycrystalline materials, nanomaterials, composite materials, etc. Specifically, a regular-shaped sample can be understood as a sample with a well-defined geometric symmetry structure, regular contours, and precisely quantifiable dimensional parameters. An irregular-shaped sample can be understood as a sample without a fixed geometric symmetry structure, with a complex shape and dimensional parameters that are difficult to describe using standard geometric quantities. A solid sample can be understood as a sample with a fixed shape and volume, with tightly packed molecules or atoms that do not easily undergo morphological flow, such as magnetic metal blocks, permanent magnets, magnetic ceramic sheets, etc. A fluid sample can be understood as a sample with fluidity, no fixed shape, and that changes shape with the container, such as magnetorheological fluids, solutions containing magnetic particles, molten magnetic materials, etc. Powder samples can be understood as loosely dispersed substances composed of fine solid particles, such as iron powder, iron-cobalt powder, magnetite powder, neodymium iron boron powder, and ferrite powder. Needle-like materials can be understood as magnetic materials that are elongated and thin, with a cross-section typically circular, square, or polygonal, exhibiting distinct axial characteristics, such as magnetic needles and slender magnetic fibers. Porous materials can be understood as magnetic materials containing numerous interconnected or closed pore structures, with pore morphologies including honeycomb, sponge-like, and porous forms, such as porous ferrites, foam magnetic alloys, and porous permanent magnet composite materials.

[0043] Specifically, the testing requirements for the samples to be tested revolve around their magnetic properties under room temperature, high temperature, and low temperature conditions. Diamagnetic materials can be understood as magnetic materials that, under the influence of an external magnetic field, exhibit a weak magnetization intensity opposite to the direction of the external magnetic field, with a negative magnetic susceptibility. Their magnetization intensity changes linearly with the strength of the external magnetic field, and the magnetization phenomenon disappears immediately after the external magnetic field is removed; examples include copper, silver, and gold. Paramagnetic materials can be understood as magnetic materials that, under the influence of an external magnetic field, exhibit a weak magnetization intensity in the same direction as the external magnetic field, with a positive magnetic susceptibility. Their magnetization intensity increases with the strength of the external magnetic field and decreases with increasing temperature, and there is no residual magnetism after the external magnetic field is removed; examples include aluminum, platinum, oxygen, and rare earth metal salts. Soft magnetic materials can be understood as magnetic materials with high permeability and low coercivity, which are easily magnetized under the influence of an external magnetic field, and the magnetism essentially disappears after the external magnetic field is removed; examples include silicon steel sheets, permalloy, and ferrite soft magnetic materials. Permanent magnet materials, also known as hard magnetic materials, refer to magnetic materials that, after being magnetized by an external magnetic field, can maintain strong remanence and high coercivity for a long time even after the external magnetic field is removed. Their magnetic properties are stable and they can continuously provide a magnetic field. Examples include rare-earth and non-rare-earth permanent magnets such as neodymium iron boron (NdFeB), samarium cobalt (SMC), AlNiCo, and ferrite. Spintronic materials can be understood as magnetic materials that utilize the spin degree of freedom of electrons rather than the traditional charge degree of freedom to achieve information storage, transmission, and processing. Examples include giant magnetoresistance (GMR) materials, tunnel magnetoresistance (TMR) materials, and spin valve materials. Multilayer film materials can be understood as magnetic or non-magnetic materials composed of two or more different compositions. Isotropic materials can be understood as magnetic materials whose magnetic properties (such as permeability, coercivity, and saturation magnetization) are basically consistent in different directions within the material. Their magnetic properties do not depend on the detection direction, and the internal grain arrangement has no obvious preferred orientation. Examples include partially sintered ferrites and non-oriented silicon steel. Anisotropic materials can be understood as magnetic materials whose magnetic properties differ significantly in different directions within the material. They typically have specific easy and difficult magnetization directions, and their magnetic properties are closely related to the detection direction. Examples include oriented silicon steel, neodymium iron boron sintered permanent magnets, and anisotropic ferrite powders. Single-crystal materials can be understood as magnetic materials composed of a single crystal, whose atoms or molecules are arranged in a regular and ordered periodic pattern without grain boundaries. Examples include single-crystal silicon steel and single-crystal ferrites. Polycrystalline materials can be understood as magnetic materials formed by a large number of randomly oriented or preferentially oriented small crystals (grains) bonded together by grain boundaries. Examples include polycrystalline neodymium iron boron and polycrystalline soft magnetic alloys. Nanomaterials can be understood as magnetic materials with at least one dimension in three-dimensional space ranging from 1 to 100 nanometers. Due to their nanoscale size, they exhibit quantum size effects, surface effects, and small size effects, and their magnetic properties differ significantly from macroscopic bulk materials. Examples include nanomagnetic particles, nanocrystalline soft magnetic alloys, and nanowire magnetic materials.Composite materials can be understood as magnetic materials composed of two or more components with different magnetic properties or functions (such as magnetic phase and non-magnetic matrix phase) through physical or chemical methods. Examples include magnetic particle reinforced polymer matrix composites, ferrite-metal composite soft magnetic materials, and permanent magnet-soft magnetic composite magnets.

[0044] The following will explain in detail how the detection equipment obtains the target detection location, including:

[0045] The sample is made to be in a stable magnetic state in the direction to be detected by applying an external magnetic field to the sample using a detection device, or by using the sample to be initially magnetized or by using an external device to magnetize it. The magnetic state is used to indicate that the magnetic material in the sample has been magnetized and that the magnetic signal is stable and easy to identify when the magnetic signal changes.

[0046] The sample rod is moved in four-dimensional space by means of the detection equipment, or by means of the coordinated adjustment of the movement of the sample rod and the fixed direction and / or fixed position of the sample to be tested on the sample cup and the sample rod, so as to realize the movement of the sample to be tested in four-dimensional space.

[0047] During the movement of the sample to be tested in four-dimensional space, the changes in magnetic signal intensity are observed. When the rate of change of the rotation direction, X-axis direction, Y-axis direction, and Z-axis direction with position is the smallest, the target detection position is determined.

[0048] In this disclosure, the position that changes the least with position is: the position where the magnetic signal intensity is the maximum in the rotation direction and the X-axis direction, and the magnetic signal intensity is the minimum in the Y-axis direction and the Z-axis direction, or the position where the magnetic signal intensity is the maximum in the rotation direction, the magnetic signal intensity is the minimum in the X-axis direction, and the magnetic signal intensity is the maximum in the Y-axis direction and the Z-axis direction.

[0049] In this disclosure, applying an external magnetic field to the sample to be tested using a detection device can be understood as directly utilizing the detection device's own magnetic field generating coil array to generate a magnetic field that meets the requirements and apply it to the sample to magnetize it and place it in a stable magnetic state. Preferably, this magnetic state is a positive magnetic state.

[0050] In this disclosure, the initial magnetization of the sample to be tested can be understood as the sample being naturally magnetized in a certain state due to its own magnetic properties or the influence of the environmental magnetic field during production and storage, without the artificial intervention of the testing personnel. Alternatively, it can be understood as the sample being artificially magnetized in a certain state due to the pre-magnetization treatment by the submitter.

[0051] In this disclosure, magnetization using external equipment can be understood as the process of applying an external magnetic field of specific intensity and direction to the sample to achieve a stable magnetic state by using a dedicated magnetization instrument independent of this testing equipment, based on the external shape or internal structural characteristics of the sample to be tested. Specific external equipment can be permanent magnet equipment, electromagnetic equipment, pulsed magnetic field equipment, etc., and is not limited here.

[0052] In this disclosure, a stable magnetized state can be understood as the magnetic domains within the sample being tested forming a certain degree of directional alignment in the direction to be detected. When the direction to be detected is consistent with the positive magnetic field direction set by the detection device, a stable magnetization state with stable magnetization intensity can be detected by a magnetic sensor. This stable magnetization state is sensitive to changes in the detection position. The magnetic signal of the sample in this state exhibits clear stability and position sensitivity, providing clear signal feedback for subsequent three-dimensional position adjustment and ensuring a reliable benchmark for the detection and comparison of magnetic signal intensity.

[0053] Specifically, when determining the target detection position, the following steps can be performed: First, start the sample rod to vibrate, and then rotate the sample to align the direction to be detected with the direction of the magnetic field, and the magnetic signal value is positive. It is important to note that when aligning the rotation direction, if the detection device itself has a rotation function, it can be rotated directly to the corresponding position. If the detection device does not have a rotation function, the sample rod and sample cup need to be removed to change the fixed orientation of the sample. The second step is to determine the initial stable magnetic state of the sample by collecting the initial magnetic signal through a magnetic sensor. If the signal strength reaches a preset threshold, the position adjustment stage is directly entered. If the initial magnetic signal is weak, a magnetization method is selected. If an external device is used for magnetization, the sample is removed, magnetized, and then reloaded. If the device itself is used for magnetization, the coil current is adjusted to enhance the positive magnetic field so that the sample reaches a positive stable magnetic state. The third step is that when the sample rod of the detection device has the ability to move in four-dimensional space, the sample can be moved by controlling the movement of the sample rod alone. When the sample rod of the detection device does not have the ability to move in four-dimensional space, the sample needs to be removed from the sample rod and sample cup, and then the fixed position of the sample is adjusted by itself or with the assistance of an external device. It is preferable to adjust the position of the sample in the X-axis, Y-axis, and Z-axis directions in multiple rounds, and collect and record the magnetic signal strength in the X-axis, Y-axis, and Z-axis directions at each step of movement. The location where the magnetic signal intensity in the X-axis direction drops to its minimum value, the magnetic signal intensity in the Y-axis direction is at its maximum value, and the magnetic signal intensity in the Z-axis direction is at its maximum value, or the location where the magnetic signal intensity in the X-axis direction is at its maximum value, the magnetic signal intensity in the Y-axis direction is at its minimum value, and the magnetic signal intensity in the Z-axis direction is at its minimum value, is determined as the target detection location.

[0054] For example, this disclosure provides specific embodiments for determining the target detection location, including:

[0055] First embodiment: Taking a detection device with a magnetic field that is an electromagnetic field and whose magnetic field distribution direction is parallel to the ground, and an anisotropic permanent magnet block-shaped sample to be tested as an example, the method for determining the target detection position includes the following steps:

[0056] Step 1: Apply an external magnetic field (pulse magnetic field) of a certain magnitude along the orientation direction of the sample to magnetize the sample and stabilize its magnetic charge;

[0057] Step 2: Fix the sample on the sample cup, sample rod and detection device (the sample orientation direction is parallel to the ground), and use the detection device to control the sample rod to move its position in four-dimensional space. Adjust the position of the sample in four-dimensional space in the X, Y, Z axis directions and the rotation direction until the magnetic signal intensity of the sample is at its maximum in the rotation direction, maximum in the Z axis direction, maximum in the Y axis direction and minimum in the X axis direction.

[0058] Step 3: After obtaining the target detection location, reduce the external magnetic field to 0. Note that this step can also be omitted.

[0059] There are no special requirements for the magnitude of the external magnetic field, but a preferred external magnetic field is ≥100 Oe, more preferably ≥2 kOe, and even more preferably ≥5 kOe. For example, Figure 2 This is a schematic diagram of the three-dimensional target detection location provided in an embodiment of this disclosure. Figure 3 This is a schematic diagram of the curve representing the three-dimensional target detection position provided in an embodiment of this disclosure. From... Figure 2 It can be seen that in the three-dimensional Cartesian coordinate system, the position marked at the origin has clear spatial positioning characteristics. The negative arrow on the X-axis indicates the region of minimum magnetic signal, while the positive arrows on the Y and Z axes point to the regions of maximum magnetic signal, intuitively demonstrating the signal intensity distribution of the target detection position in the spatial coordinate system. From Figure 3 It can be seen that the magnetic signal curve in the X-axis direction exhibits a concave valley shape, reaching its minimum value at the target detection position; the magnetic signal curves in the Y-axis and Z-axis directions both exhibit convex peaks, reaching their maximum values ​​simultaneously. The three curves intersect at the position coordinates through a vertical dashed line, clearly presenting the extreme value characteristics of the three-dimensional magnetic signal intensity at the target detection position.

[0060] Second embodiment: Taking a detection device with a superconducting magnetic field and a magnetic field direction perpendicular to the ground direction, and an isotropic spherical iron-silicon-aluminum bulk material as an example, the method for determining the target detection position includes the following steps:

[0061] Step 1: Apply an external magnetic field of a certain magnitude using detection equipment to magnetize and stabilize the sample;

[0062] Step 2: Adjust the spatial position of the sample in the Z-axis and Y-axis directions by moving the sample to a fixed position on the sample cup, sample rod, and detection device. Then, adjust the spatial position of the sample in the X-axis direction by moving the sample rod until the magnetic signal intensity of the sample is at its maximum in the rotation direction, maximum in the X-axis direction, and minimum in the Y-axis direction; this is the target detection position. For example, Figure 4 This is a schematic diagram showing the curves illustrating the two-dimensional target detection positions along the Y-axis and Z-axis directions provided in an embodiment of this disclosure. From... Figure 4 It can be seen that the magnetic signal intensity curves in both the Y-axis and Z-axis directions exhibit a symmetrical single-peak distribution. The two curves reach their troughs at the same parallel ground position, meaning that the magnetic signal intensity in both the Y-axis and Z-axis directions simultaneously reaches its minimum value. This position is marked by a vertical dashed line as the target detection position. The curves show a symmetrical upward trend as the sample position deviates from the position, clearly demonstrating the extreme value correspondence of the two-dimensional magnetic signal intensity at the target detection position.

[0063] The following will explain in detail how to use the target detection location to determine the magnetic detection curve of the target location, including:

[0064] When the sample to be tested is positioned at the target detection location, the coil drive module of the detection device is activated, an external magnetic field is applied to the sample to be tested according to the preset magnetic field strength gradient program, and the magnetic response signal of the sample to be tested is collected.

[0065] Determine the magnetic detection curve of the target position with the magnetic response signal M as the vertical axis and the magnetic field strength H, time t, or temperature T as the horizontal axis.

[0066] In this disclosure, the coil drive module can be understood as a functional module in the detection device responsible for controlling the operation of the magnetic field generating coil. This module can smoothly adjust the current magnitude according to preset magnetic field gradient parameters to provide a preset gradient magnetic field strength.

[0067] Specifically, when determining the magnetic detection curve for the target location, the following steps can be performed: Step 1: After the sample rod stabilizes the sample at the target detection position, based on the target magnetic characteristic requirements of the sample, preset the magnetic field strength gradient parameters, and gradually increase, decrease, or maintain the magnetic field strength according to the preset gradient. At each preset magnetic field strength point, maintain the magnetic field stability for a period of time to ensure the sample fully responds to the current magnetic field strength, time, or temperature. Simultaneously, acquire the corresponding magnetic response signal data and accurately record the magnetic field strength value and the corresponding magnetic response signal value. Step 2: After acquiring the magnetic response signals under all preset magnetic field strength gradients, organize and pair the acquired magnetic field strength values ​​with the corresponding magnetic response signal values. Plot the magnetic response signal M as the ordinate and the magnetic field strength H and time t or temperature T as the abscissa to create the magnetic detection curve for the target location.

[0068] The following will explain in detail how to directly extract the target detection magnetic features using the target location magnetic detection curve, including:

[0069] The original data points corresponding to the magnetic response signal M, magnetic field strength H, time t, and temperature T in the magnetic detection curve obtained during the magnetic detection process can be directly extracted as the target detection magnetic features, or the magnetic detection curve can be mathematically calculated according to a preset formula relationship before directly extracting the target detection magnetic features.

[0070] In one embodiment of this disclosure, for magnetic detection scenarios where the target magnetic response signal is stable and interference noise is below a preset threshold, a continuous data segment corresponding to the target position is directly extracted from the magnetic detection curve. The original values ​​of the magnetic response signal M and the original values ​​of the magnetic field strength H, time t, or temperature T corresponding to each sampling time within this data segment are extracted to form a feature data set, which is used as the magnetic feature for target detection. The sampling time sequence and numerical accuracy of the original data are preserved during the extraction process, requiring no additional data processing.

[0071] In another embodiment of this disclosure, mathematical calculation formulas are first preset according to the application scenario of magnetic detection, including but not limited to the calculation of magnetic induction intensity B = μ0(M+H), magnetic permeability μ = B / H, magnetic energy product |BH| = -B×H, numerical integration of hysteresis loss P = ∮HdM, first derivative calculation of magnetic response signal M and corresponding magnetic field intensity H, second derivative calculation, etc. Based on the above preset formulas, the full data of the magnetic detection curve is calculated point by point or interval by interval to obtain derived data such as magnetic induction intensity curve, magnetic permeability curve, magnetic energy product curve, maximum magnetic energy product value, hysteresis loss value, dM / dH characteristic parameters, etc. Key feature points, feature interval statistical values ​​or feature curve morphology parameters are extracted from the derived data as target detection magnetic features to improve the recognition of target attributes by features.

[0072] The following will explain in detail how to use the magnetic detection curve at the target location to correct the magnetic detection curve at the non-target location, including:

[0073] Select a magnetic field strength, and determine the ratio of the magnetic response signal of the magnetic detection curve at the target location to the magnetic response signal of the magnetic detection curve at the non-target location for the selected magnetic field strength, and determine the mean or weighted mean of the ratio as a correction factor;

[0074] The magnetic response signal corresponding to the magnetic detection curve at the non-target detection location is multiplied by the correction factor to obtain the corrected magnetic detection curve.

[0075] Based on the corrected magnetic detection curve, the target detection features are extracted and determined.

[0076] In this disclosure, the correction factor can be understood as a correction parameter constructed based on the difference between the magnetic detection curves of the target position and the non-target position, used to reduce the systematic error of the non-ideal detection position. Its essence is the quantitative value of the proportional relationship between the magnetic response signals of the two positions under the same magnetic field conditions.

[0077] In this disclosure, the selected magnetic field strength can be any magnetic field strength or a series of magnetic field strengths that meet certain conditions. Preferably, the magnetic field strength corresponding to the strong magnetic response signal in the test magnetic curve is selected, and further preferably, the magnetic field strength when the magnetic signal is close to or reaches the strongest is selected.

[0078] Specifically, when correcting the magnetic detection curve at a non-target location to obtain target detection features, the following steps can be performed: Step 1: First, retrieve the complete data of the magnetic detection curve at the target location (denoted as Curve 1) and the magnetic detection curve at the non-target location to be corrected (denoted as Curve 2), ensuring that the magnetic field strength detection range of the two curves is consistent. Step 2: Traverse all aligned magnetic field strength sampling points, select the magnetic field strength according to the characteristics of the detection curve and detection requirements, and calculate the ratio of the magnetic response signal value of Curve 1 to the magnetic response signal value of Curve 2 for the selected magnetic field strength. If the mean method is used, take the arithmetic mean of the remaining effective ratios to obtain the correction factor K; if the weighted mean method is used, assign weights according to the importance of the magnetic field strength intervals (e.g., 0.4 for the high magnetic field near-saturation region, 0.4 for the linear region, and 0.2 for the zero-crossing region), calculate the weighted sum of the ratios within each interval, and obtain the correction factor K. Step 3: Multiply the magnetic response signal value of each sampling point in Curve 2 by the correction factor K to obtain the corrected magnetic response signal value of each sampling point. Then, using the original magnetic curve's x-axis as the x-axis and the corrected magnetic response signal value as the y-axis, a new curve is drawn, which is the corrected non-target position magnetic detection curve (denoted as curve three). Fourth step: Referring to the method for extracting features based on the target position magnetic detection curve, feature extraction is performed on the corrected curve three. Specific details can be found above and will not be repeated here. The second and third steps can also be as follows: Second step: Extract the maximum magnetization values ​​of curve one (target position magnetic detection curve) and curve two (non-target position magnetic detection curve), denoted as M. m1 (maximum magnetization at target location) and M m2 (Maximum magnetization at non-target locations); calculate correction factor K = M m1 / M m2(Using the maximum magnetization at the target location as a benchmark, establish a correction coefficient for the saturation magnetization of the non-target location curve). Third step: Multiply the magnetic response signal value at each sampling point in Curve 2 by the correction factor K to obtain the corrected magnetic response signal value for each sampling point; keeping the horizontal axis unchanged, redraw the curve using the corrected magnetic response signal value as the vertical axis, which is the non-target location magnetic detection curve after single correction of the maximum magnetization (denoted as Curve 3). Fourth step is the same as above and will not be repeated here.

[0079] For example, this disclosure also provides specific embodiments for obtaining target detection features from magnetic curves at non-target locations, including:

[0080] Methods for obtaining target detection features at non-target locations include:

[0081] Step 1: Measure magnetic curve 1. Step 2: Measure magnetic curve 2 according to the four-dimensional detection position of the external magnetic field (i.e., the target detection position of this disclosure). Step 3: Correct the measured curve 1 according to the magnetic response signal value and / or maximum magnetization of magnetic curve 2. After extracting the magnetic parameters from the corrected magnetic curve 1, obtain the detection result.

[0082] Methods for acquiring target detection features at non-target locations using variable temperature options include:

[0083] According to the test method adjusted by the four-dimensional detection position of the external magnetic field (i.e., the target detection position of this disclosure), the first magnetic curve S at room temperature under the condition of no temperature change option was tested. c Then, with the variable temperature option, the second magnetic curve S at room temperature, which only has vertical position adjustment, was measured. hc And detection curves S at other target temperatures T According to the first magnetic curve S at room temperature c and the second magnetic curve S at room temperature hc Calculate the correction factor, and then use the correction factor to adjust the target temperature detection curve S. T After correction, the magnetic value is calculated to obtain the magnetic detection result.

[0084] The magnetic measurement method of this disclosure is further described below, including:

[0085] The testing equipment is calibrated using standard samples.

[0086] In this disclosure, a standard sample can be understood as a reference sample with known, stable, and precise magnetic characteristic parameters, whose magnetic properties have been calibrated by an authoritative institution. By utilizing its clearly defined magnetic characteristic benchmark, the test results of the standard sample can be compared with those of the testing equipment to pinpoint systematic errors in the equipment's magnetic field generation, signal acquisition, and data processing stages, providing a quantitative basis for the precise correction of equipment parameters. Specific correction processes can refer to existing methods and are not limited thereto.

[0087] This disclosure also provides a magnetic detection device. Figure 5 This is a structural block diagram of a magnetic detection device provided in an embodiment of the present disclosure, such as... Figure 5 As shown, the magnetic detection device 500 includes:

[0088] The fixing unit 501 is used to install the sample to be tested into the sample cup and fix the sample cup to the sample rod and the testing equipment;

[0089] The determining unit 502 is used to start the vibration of the sample rod, and based on the target detection magnetic characteristics of the sample to be tested, the four-dimensional spatial position movement capability of the sample rod, and the coil structure and magnetic field distribution direction of the detection device, adjust the four-dimensional spatial position of the sample, observe the change of magnetic signal, and determine the target detection position; the target detection position is the position in the magnetic field area of ​​the detection device where the rate of change of magnetic signal is the smallest when the position of the sample to be tested changes.

[0090] The acquisition unit 503 is used to position the sample to be tested at the target detection position, perform magnetic curve detection on the sample to be tested, and obtain the magnetic detection curve at the target position.

[0091] Extraction unit 504 is used to directly extract the magnetic features of target detection based on the magnetic detection curve of the target position; or to calculate a correction factor based on the magnetic detection curve of the target position, and then use the correction factor to correct the magnetic detection curve of the non-target detection position before extracting the magnetic features of target detection.

[0092] In one exemplary embodiment, the fixing unit 501 is specifically used for: the sample to be tested, including but not limited to samples with regular shapes, samples with irregular shapes, solid samples, fluid samples, powder samples, needle-like materials, porous materials, etc.; the sample to be tested is a magnetic material under room temperature and high / low temperature conditions. Measurable magnetic materials include, but are not limited to, diamagnetic materials, paramagnetic materials, soft magnetic materials, permanent magnet materials, spintronic materials, multilayer film materials, isotropic materials, anisotropic materials, single crystal materials, polycrystalline materials, nanomaterials, composite materials, etc.

[0093] In one exemplary embodiment, the determining unit 502 is specifically used for: detecting magnetic features of the target, including but not limited to at least one of the following magnetic curves or magnetic parameters: hysteresis loop, initial magnetization curve, demagnetization curve, small hysteresis curve, DC remanence curve, AC remanence curve, magnetization intensity time function curve, magnetization intensity temperature function curve, first-order reversal curve FORC, rotation angle test curve, saturation magnetization, remanence, coercivity, intrinsic coercivity, maximum energy product, saturation magnetic field, maximum permeability, initial permeability, recovered permeability, squareness; the test temperature conditions for the magnetic curves or magnetic parameters are one or a combination of room temperature constant temperature, low temperature constant temperature, high temperature constant temperature, or variable temperature; the four-dimensional spatial position movement capability includes: X-axis movement capability, Y-axis movement capability, Z-axis movement capability, and rotation capability; the magnetic field distribution direction includes: magnetic field direction parallel to the ground and magnetic field direction perpendicular to the ground.

[0094] In one exemplary embodiment, the determining unit 502 is specifically configured to: apply an external magnetic field to the sample to be tested using a detection device, or utilize at least one of the following methods: initially magnetizing the sample to be tested, or magnetizing it using an external device, to ensure that the sample to be tested is in a stable magnetic state in the direction to be tested; the magnetic state is used to indicate that the magnetic material in the sample to be tested has been magnetized, and that the magnetic signal is stable and easily identifiable when the magnetic signal changes; control the sample rod to move its position in four-dimensional space using the detection device, or move the sample rod to a fixed direction and / or fix the sample to be tested on the sample cup and the sample rod. The coordinated adjustment of position enables the movement of the sample to be tested in four-dimensional space. During the movement of the sample to be tested in four-dimensional space, the change of magnetic signal intensity is observed. When the change of magnetic signal intensity in the rotation direction, X-axis direction, Y-axis direction, and Z-axis direction with position is minimal (corresponding to the position with the maximum magnetic signal intensity in the rotation direction, the minimum magnetic signal intensity in the X-axis direction, and the maximum magnetic signal intensity in the Y-axis direction and Z-axis direction respectively, or the position with the maximum magnetic signal intensity in the rotation direction and X-axis direction and the minimum magnetic signal intensity in the Y-axis direction and Z-axis direction respectively), the target detection position is determined.

[0095] In one exemplary embodiment, the acquisition unit 503 is specifically used to: when the sample to be tested moves and is positioned at the target detection position, start the coil drive module of the detection device, apply an external magnetic field to the sample to be tested according to a preset magnetic field strength gradient program, and acquire the magnetic response signal of the sample to be tested; determine the target position magnetic detection curve with the magnetic response signal M as the vertical axis and the magnetic field strength H and time t or temperature T as the horizontal axis.

[0096] In one exemplary embodiment, the extraction unit 504 is specifically used to: directly extract the original data points corresponding to the magnetic response signal M, magnetic field strength H, time t, and temperature T from the magnetic detection curve obtained during the magnetic detection process as the target detection magnetic features, or first perform mathematical operations on the magnetic detection curve according to a preset formula relationship and then directly extract the target detection magnetic features.

[0097] In one exemplary embodiment, the extraction unit 504 is specifically configured to: select a magnetic field strength, and determine the ratio of the magnetic response signal of the magnetic detection curve at the target location to the magnetic response signal of the magnetic detection curve at the non-target detection location for the selected magnetic field strength, and determine the mean or weighted mean of the ratio as a correction factor; multiply the magnetic response signal corresponding to the magnetic detection curve at the non-target detection location by the correction factor to obtain the corrected magnetic detection curve; and extract and determine the target detection features based on the corrected magnetic detection curve.

[0098] In one exemplary embodiment, the fixing unit 501 is further configured to: calibrate the detection equipment using a standard sample.

[0099] In summary, this disclosure provides a magnetic detection method and apparatus. The method involves: S1: installing the sample to be tested into a sample cup, and fixing the sample cup to the sample rod and the detection device; S2: activating the sample rod and determining the target detection position based on the target magnetic characteristics of the sample, the four-dimensional spatial mobility of the sample rod, and the coil structure and magnetic field distribution direction of the detection device; the target detection position is the position in the magnetic field region of the detection device where the rate of change of the magnetic signal is minimal when the sample is displaced; S3: controlling the sample rod to move the sample to the target detection position, performing magnetic curve detection on the sample to obtain the magnetic detection curve at the target position; S4: directly extracting the target magnetic characteristics based on the magnetic detection curve at the target position; or calculating a correction factor based on the magnetic detection curve at the target position, using the correction factor to correct the magnetic detection curves acquired at non-target detection positions, and then extracting the target magnetic characteristics. In contrast to existing methods that rely on multiple measurements or parallel standards to reduce errors in vibrating sample magnetometer measurements, this disclosure reduces signal fluctuation interference caused by sample displacement at the source by locating the target detection position with the smallest rate of change of magnetic signal. Even if there are deviations in the initial positioning of the sample or individual differences in its morphological characteristics and structural homogeneity, the influence of these factors on the detection results can be offset by precise position adjustment. Furthermore, the introduction and flexible application of correction factors effectively corrects detection data from non-ideal positions, further improving the reliability of magnetic feature extraction. In summary, the technical solution provided by this disclosure effectively overcomes the limitations of existing methods that rely on multiple measurements or parallel standards, expanding application scenarios and improving measurement accuracy while ensuring detection precision, making it adaptable to various application scenarios.

[0100] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0101] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0102] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0103] Additionally, as used herein, the “or” used in a list of items beginning with “at least one” indicates a separate list, such that a list of, for example, “at least one of A, B, or C” means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word “exemplary” does not imply that the described example is preferred or better than other examples.

[0104] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0105] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0106] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0107] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A magnetic detection method, characterized in that, The method includes: S1: Install the sample to be tested into the sample cup, and fix the sample cup to the sample rod and the testing equipment; S2: The sample rod is activated, and based on the target detection magnetic characteristics of the sample to be tested, the four-dimensional spatial position movement capability of the sample rod, and the coil structure and magnetic field distribution direction of the detection device, the four-dimensional spatial position of the sample is adjusted, the change of magnetic signal is observed, and the target detection position is determined; the target detection position is the position in the magnetic field region of the detection device where the rate of change of magnetic signal is the smallest when the position of the sample to be tested changes. S3: Position the sample to be tested at the target detection position, perform magnetic curve detection on the sample to be tested, and obtain the magnetic detection curve at the target position; S4: Based on the magnetic detection curve at the target location, directly extract the target detection magnetic features; or calculate a correction factor based on the magnetic detection curve at the target location, use the correction factor to correct the magnetic detection curves collected at non-target detection locations, and then extract the target detection magnetic features.

2. The method according to claim 1, characterized in that, The samples to be tested include: samples with regular shapes, samples with irregular shapes, solid samples, fluid samples and powder samples, needle-like materials, and porous materials; The sample to be tested is a magnetic material under normal temperature or high and low temperature conditions; the magnetic material includes: diamagnetic material, paramagnetic material, soft magnetic material, permanent magnet material, spintronic material, multilayer film material, isotropic material, anisotropic material, single crystal material, polycrystalline material, nanomaterial, and composite material.

3. The method according to claim 1, characterized in that, The target detection magnetic characteristics include one of the following magnetic curves or magnetic parameters: hysteresis loop, initial magnetization curve, demagnetization curve, small hysteresis curve, DC remanence curve, AC remanence curve, magnetization intensity time function curve, magnetization intensity temperature function curve, first-order reversal curve FORC, rotation angle test curve, saturation magnetization, remanence, coercivity, intrinsic coercivity, maximum energy product, saturation magnetic field, maximum permeability, initial permeability, recovered permeability, and squareness. The test temperature conditions for the magnetic curve or magnetic parameters are one or a combination of constant room temperature, constant low temperature, constant high temperature, or variable temperature. The four-dimensional spatial positional movement capability includes: movement capability in the X-axis direction, movement capability in the Y-axis direction, movement capability in the Z-axis direction, and rotation capability; The magnetic field distribution direction includes: the magnetic field direction parallel to the ground and the magnetic field direction perpendicular to the ground; The X-axis, Y-axis, and Z-axis are directions of a three-dimensional coordinate system, with the X-axis being parallel to the magnetic field direction and the Y-axis and Z-axis being perpendicular to the magnetic field direction.

4. The method according to claim 1, characterized in that, The process of activating the sample rod, and adjusting the four-dimensional spatial position of the sample based on the target magnetic characteristics of the sample to be tested, the four-dimensional spatial mobility of the sample rod, and the coil structure and magnetic field distribution characteristics of the detection device, observing changes in the magnetic signal, and determining the target detection position includes: The detection device is used to apply an external magnetic field to the sample to be tested, or the sample to be tested is initially magnetized, or the sample is magnetized by an external device, so that the sample to be tested is in a stable magnetic state in the direction to be tested; the stable magnetic state is used to indicate that the magnetic material in the sample to be tested has been magnetized, and the magnetic signal is stable and easy to identify when the magnetic signal changes. The detection device controls the movement of the sample rod in four-dimensional space, or the movement of the sample rod is coordinated with the fixed direction and / or fixed position of the sample to be tested on the sample cup and the sample rod to achieve the movement of the sample to be tested in four-dimensional space. During the movement of the sample to be tested in four-dimensional space, the change in magnetic signal intensity is observed. When the change in rotation direction, X-axis direction, Y-axis direction, and Z-axis direction with position is minimal, it is determined as the target detection position.

5. The method according to claim 1, characterized in that, The step of locating the sample to be tested at the target detection position and performing magnetic curve detection on the sample to be tested to obtain the magnetic detection curve at the target position includes: When the sample to be tested is moved and positioned at the target detection position, the coil drive module of the detection device is activated, an external magnetic field is applied to the sample to be tested according to a preset magnetic field strength gradient program, and the magnetic response signal of the sample to be tested is collected. Determine the magnetic detection curve of the target position with the magnetic response signal M as the vertical axis and the magnetic field strength H, time t, or temperature T as the horizontal axis.

6. The method according to claim 1, characterized in that, The direct extraction of the target detection magnetic features includes: The original data points corresponding to the magnetic response signal M, magnetic field strength H, time t, and temperature T in the magnetic detection curve obtained during the magnetic detection process can be directly extracted as the target detection magnetic features, or the magnetic detection curve can be mathematically calculated according to a preset formula relationship before directly extracting the target detection magnetic features.

7. The method according to claim 1, characterized in that, The process of calculating a correction factor based on the magnetic detection curve at the target location, correcting the magnetic detection curves acquired at non-target detection locations using the correction factor, and then extracting the target detection magnetic features includes: Select a magnetic field strength, and determine the ratio of the magnetic response signal of the magnetic detection curve at the target location to the magnetic response signal of the magnetic detection curve at the non-target location for the selected magnetic field strength, and determine the mean or weighted mean of the ratio as the correction factor; The magnetic response signal corresponding to the magnetic detection curve at the non-target detection location is multiplied by the correction factor to obtain the corrected magnetic detection curve. Based on the corrected magnetic detection curve, the target detection features are extracted and determined.

8. The method according to claim 1, characterized in that, The method further includes: The testing equipment is calibrated using a standard sample.

9. A magnetic detection device, characterized in that, The device includes: A fixing unit is used to install the sample to be tested into the sample cup and fix the sample cup to the sample rod and the testing equipment; The determining unit is used to activate the sample rod and, based on the target detection magnetic characteristics of the sample to be tested, the four-dimensional spatial position movement capability of the sample rod, and the coil structure and magnetic field distribution direction of the detection device, adjust the four-dimensional spatial position of the sample, observe the changes in the magnetic signal, and determine the target detection position; the target detection position is the position in the magnetic field region of the detection device where the rate of change of the magnetic signal is the smallest when the position of the sample to be tested changes. The acquisition unit is used to move and position the sample to be detected at the target detection position, perform magnetic curve detection on the sample to be detected, and obtain the magnetic detection curve at the target position. The extraction unit is used to directly extract the target detection magnetic features based on the magnetic detection curve of the target location; or to calculate a correction factor based on the magnetic detection curve of the target location, and then use the correction factor to correct the magnetic detection curves collected at non-target detection locations before extracting the target detection magnetic features.

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