阅读说明：本技术 一种测量物体磁特性的装置及方法 (Device and method for measuring magnetic characteristics of object ) 是由 尹航 李贵琳 周泽兵 于 2021-08-27 设计创作，主要内容包括：本发明提供一种测量物体磁特性的装置及方法,装置包括：悬挂机构、载物台、磁场调制结构、载物台极板、传感极板以及测量与控制系统；悬挂机构通过悬丝将载物台悬挂；载物台为镂空框架,其框架内部用于放置待测物体,所述待测物体与载物台底部固定连接；磁场调制结构置于载物台周围,以向载物台及载物台内部提供磁场环境；所述磁场环境的磁场分布可控；测量与控制系统,用于通过测量载物台极板与传感极板之间电容的变化确定所述磁力矩的大小,并根据磁场环境的磁场分布情况、磁力矩大小确定所述待测物体的磁特性参数,磁特性参数包括：剩磁和磁化率。本发明可以解决常规测量手段无法测量形状不规则大尺寸宏观物体磁特性的问题。(The invention provides a device and a method for measuring the magnetic property of an object, wherein the device comprises: the device comprises a suspension mechanism, an objective table, a magnetic field modulation structure, an objective table polar plate, a sensing polar plate and a measurement and control system; the suspension mechanism suspends the objective table through suspension wires; the object stage is a hollow frame, an object to be measured is placed in the frame, and the object to be measured is fixedly connected with the bottom of the object stage; the magnetic field modulation structure is arranged around the objective table to provide a magnetic field environment for the objective table and the interior of the objective table; the magnetic field distribution of the magnetic field environment is controllable; the measurement and control system is used for determining the size of the magnetic moment by measuring the change of capacitance between the polar plate of the objective table and the sensing polar plate, and determining the magnetic characteristic parameters of the object to be measured according to the magnetic field distribution condition and the magnetic moment size of the magnetic field environment, wherein the magnetic characteristic parameters comprise: remanence and magnetic susceptibility. The invention can solve the problem that the conventional measuring means can not measure the magnetic characteristics of the large-size macroscopic object with irregular shape.)

1. An apparatus for measuring a magnetic property of an object, comprising: the device comprises a suspension mechanism, an objective table, a magnetic field modulation structure, an objective table polar plate, a sensing polar plate and a measurement and control system;

the suspension mechanism comprises a suspension wire and is used for suspending the objective table through the suspension wire, so that the objective table can be freely twisted in the twisting direction around the suspension wire;

the object stage is a hollow frame, an object to be measured is placed in the frame, and the object to be measured is fixedly connected with the bottom of the object stage;

the magnetic field modulation structure is arranged around the objective table so as to provide a magnetic field environment for the objective table and the interior of the objective table; the magnetic field distribution of the magnetic field environment is controllable;

the object stage polar plate is fixedly connected with the bottom of the object stage, and the sensing polar plate is arranged below the object stage and opposite to the object stage polar plate;

the suspension wire, the objective table and the object to be tested jointly form a torsional pendulum, and the object to be tested interacts with a magnetic field in a magnetic field environment to generate magnetic torque so that the torsional pendulum is twisted;

the measurement and control system is used for determining the magnetic moment by measuring the change of capacitance between the polar plate of the objective table and the sensing polar plate, and determining the magnetic characteristic parameters of the object to be measured according to the magnetic field distribution condition of the magnetic field environment and the magnetic moment, wherein the magnetic characteristic parameters comprise: remanence and magnetic susceptibility.

2. The apparatus according to claim 1, wherein the measurement and control system is configured to determine the magnitude of the magnetic moment by measuring a change in capacitance between the stage plate and the sensing plate, and comprises:

under the condition that the object stage is unloaded, the condition that the object stage is unloaded means that the object to be detected is not placed in the object stage; the magnetic field modulation structure applies the magnetic field environment to the object stage, the hollow object stage can be acted by magnetic torque in the magnetic field environment, and the magnetic torque of the no-load object stage is measured by the measurement and control system and is represented as tau₀；

When an object to be measured is placed in the objective table, the magnetic field modulation structure reapplies the objective table in the magnetic field environment, and the measurement and control system measures the resultant magnetic moment of the objective table and the object to be measured in the magnetic field environment, which is expressed as tau_t；

The two measurements are combined, and the object to be measured is subjected to the magnetic moment tau in the magnetic field_mThe object stage and the object to be measured are integrated into a magnetic torque tau measured by the measurement and control system_tSubtracting the magnetic moment tau borne by the empty-load stage₀Is obtained, i.e. tau_m＝τ_t-τ₀。

3. The apparatus for measuring magnetic properties of an object according to claim 1 or 2, further comprising: a plurality of leveling nuts;

the leveling nuts are arranged above the objective table and connected with the objective table;

the torsion pendulum further comprises the plurality of leveling nuts;

the object that the whole that objective table, object to be measured and a plurality of leveling nut constitute is connected as the suspension wire below, a plurality of leveling nut are used for adjusting the equivalent barycenter of suspension wire below connection object, make its equivalent barycenter arrange in on the straight line that the suspension wire belongs to guarantee the steady of twisting pendulum.

4. An apparatus for measuring the magnetic properties of an object as claimed in claim 1 or 2, wherein the stage is fabricated from a lightweight material, and the lightweight material is required to be paramagnetic.

5. An apparatus for measuring the magnetic properties of an object as claimed in claim 1 or 2, wherein the stage is designed such that the shape and mass of the object to be measured are not limited.

6. A method of measuring a magnetic property of an object, comprising the steps of:

the objective table is suspended through the suspension wires, so that the objective table can be freely twisted in the twisting direction around the suspension wires; the object stage is a hollow frame, an object to be measured is placed in the frame, and the object to be measured is fixedly connected with the bottom of the object stage; the bottom of the objective table is fixedly connected with an objective table polar plate, a sensing polar plate is arranged below the objective table, and the sensing polar plate and the objective table polar plate are oppositely arranged;

providing a magnetic field environment to the object stage and the interior of the object stage; the magnetic field distribution of the magnetic field environment is controllable; the suspension wire, the objective table and the object to be tested jointly form a torsional pendulum, and the object to be tested interacts with a magnetic field in a magnetic field environment to generate magnetic torque so that the torsional pendulum is twisted;

the size of the magnetic moment is determined by measuring the change of capacitance between the objective table polar plate and the sensing polar plate, and the magnetic characteristic parameters of the object to be detected are determined according to the magnetic field distribution condition of the magnetic field environment and the size of the magnetic moment, wherein the magnetic characteristic parameters comprise: remanence and magnetic susceptibility.

7. The method of claim 6, wherein determining the magnitude of the magnetic moment by measuring a change in capacitance between the stage plate and the sensing plate comprises:

under the condition that the object stage is unloaded, the condition that the object stage is unloaded means that the object to be detected is not placed in the object stage; applying the magnetic field environment to the object stage, wherein the hollow object stage is under the action of magnetic moment in the magnetic field environment, and measuring the magnetic moment of the no-load object stage, wherein the magnetic moment is represented as tau₀；

When the object to be measured is placed in the objective table, the magnetic field environment is applied to the objective table again, and the resultant magnetic moment of the objective table and the object to be measured in the magnetic field environment is measured and expressed as tau_t；

The two measurements are combined, and the object to be measured is subjected to the magnetic moment tau in the magnetic field_mThe object stage and the object to be measured are integrated into a magnetic torque tau_tSubtracting the magnetic moment tau borne by the empty-load stage₀Is obtained, i.e. tau_m＝τ_t-τ₀。

8. A method of measuring a magnetic property of an object according to claim 6 or 7, further comprising the steps of:

placing a plurality of leveling nuts above the objective table and connecting the leveling nuts with the objective table; the object that the whole that objective table, object to be measured and a plurality of leveling nut constitute is connected as the suspension wire below, a plurality of leveling nut are used for adjusting the equivalent barycenter of suspension wire below connection object, make its equivalent barycenter arrange in on the straight line that the suspension wire belongs to guarantee the steady of twisting pendulum.

9. A method of measuring a magnetic property of an object according to claim 6 or 7 wherein the stage is fabricated from a lightweight material and the lightweight material is required to be a paramagnetic material.

10. A method of measuring a magnetic property of an object according to claim 6 or 7, wherein the stage is designed such that the shape and mass of the object to be measured are not limited.

Technical Field

The invention belongs to the field of precision measurement, and particularly relates to a device and a method for measuring magnetic properties of an object.

Background

Materials are distributed in every corner of life of people, most of the materials are magnetic, and particularly, the materials with the magnetism are widely applied to the fields of scientific research, precision manufacturing, aerospace and the like, but the magnetism of the materials can interfere with instruments and equipment and scientific research devices, so that the materials are very important for accurately measuring the magnetism of the materials.

The traditional method for measuring the magnetic property of the object cannot simultaneously measure parameters such as the magnetic susceptibility, the residual magnetism and the like of the object and is limited by the size and the shape of a sample to be measured, so that the device for measuring the magnetic property of the object, which can simultaneously meet the conditions, is particularly important.

The torsion pendulum is a mature technology, is sensitive to acting force in the torsion direction of a suspension wire around the torsion pendulum, is insensitive and inhibited to the action in the non-torsion direction, and can convert the magnetic force borne by a sample to the torsion pendulum sensitive direction by utilizing the characteristic of the torsion pendulum, so that the magnetic force can be accurately measured, the magnetic characteristics of the sample such as remanence, magnetic susceptibility and the like can be obtained, and the magnetic characteristics of an object to be measured can be measured in a mode of suspending the object to be measured by the torsion pendulum. However, the premise of suspending the magnetism of the object to be measured by the torsional pendulum device is that the object to be measured must be suspended, which results in the inconvenience of suspending the object to be measured, and the difficulty of measuring the object to be measured having a large size.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a device and a method for measuring the magnetic property of an object, and aims to solve the problem that the conventional method cannot measure the magnetic property of the object with irregular shape or large size with high precision.

To achieve the above object, in a first aspect, the present invention provides an apparatus for measuring a magnetic property of an object, comprising: the device comprises a suspension mechanism, an objective table, a magnetic field modulation structure, an objective table polar plate, a sensing polar plate and a measurement and control system;

the suspension mechanism comprises a suspension wire and is used for suspending the objective table through the suspension wire, so that the objective table can be freely twisted in the twisting direction around the suspension wire;

the object stage is a hollow frame, an object to be measured is placed in the frame, and the object to be measured is fixedly connected with the bottom of the object stage;

the magnetic field modulation structure is arranged around the objective table so as to provide a magnetic field environment for the objective table and the interior of the objective table; the magnetic field distribution of the magnetic field environment is controllable;

the object stage polar plate is fixedly connected with the bottom of the object stage, and the sensing polar plate is arranged below the object stage and opposite to the object stage polar plate;

the suspension wire, the objective table and the object to be tested jointly form a torsional pendulum, and the object to be tested interacts with a magnetic field in a magnetic field environment to generate magnetic torque so that the torsional pendulum is twisted;

the measurement and control system is used for determining the magnetic moment by measuring the change of capacitance between the polar plate of the objective table and the sensing polar plate, and determining the magnetic characteristic parameters of the object to be measured according to the magnetic field distribution condition of the magnetic field environment and the magnetic moment, wherein the magnetic characteristic parameters comprise: remanence and magnetic susceptibility.

In an optional example, the measurement and control system is configured to determine the magnitude of the magnetic moment by measuring a change in capacitance between the stage plate and the sensing plate, and specifically includes:

under the condition that the object stage is unloaded, the condition that the object stage is unloaded means that the object to be detected is not placed in the object stage; the magnetic field modulation structure applies the magnetic field environment to the object stage, the hollow object stage can be acted by magnetic torque in the magnetic field environment, and the magnetic torque of the no-load object stage is measured by the measurement and control system and is represented as tau₀(ii) a The measurement and control system in this application is exemplified by capacitance displacement sensing and electrostatic control, but the actual device can adopt this method, but is not limited thereto.

When an object to be measured is placed in the objective table, the magnetic field modulation structure reapplies the objective table in the magnetic field environment, and the measurement and control system measures the resultant magnetism of the objective table and the object to be measured in the magnetic field environmentMoment, denoted as τ_t；

The two measurements are combined, and the object to be measured is subjected to the magnetic moment tau in the magnetic field_mThe object stage and the object to be measured are integrated into a magnetic torque tau measured by the measurement and control system_tSubtracting the magnetic moment tau borne by the empty-load stage₀Is obtained, i.e. tau_m＝τ_t-τ₀。

In an optional example, the apparatus further comprises: a plurality of leveling nuts;

the leveling nuts are arranged above the objective table and connected with the objective table;

the torsion pendulum further comprises the plurality of leveling nuts;

the object that the whole that objective table, object to be measured and a plurality of leveling nut constitute is connected as the suspension wire below, a plurality of leveling nut are used for adjusting the equivalent barycenter of suspension wire below connection object, make its equivalent barycenter arrange in on the straight line that the suspension wire belongs to guarantee the steady of twisting pendulum.

In an alternative example, the stage is fabricated from a lightweight material, and the lightweight material is desirably paramagnetic.

In an alternative example, the stage is designed such that the shape and mass of the object to be measured are not limited.

In a second aspect, the present invention provides a method of measuring a magnetic property of an object, comprising the steps of:

the objective table is suspended through the suspension wires, so that the objective table can be freely twisted in the twisting direction around the suspension wires; the object stage is a hollow frame, an object to be measured is placed in the frame, and the object to be measured is fixedly connected with the bottom of the object stage; the bottom of the objective table is fixedly connected with an objective table polar plate, a sensing polar plate is arranged below the objective table, and the sensing polar plate and the objective table polar plate are oppositely arranged;

providing a magnetic field environment to the object stage and the interior of the object stage; the magnetic field distribution of the magnetic field environment is controllable; the suspension wire, the objective table and the object to be tested jointly form a torsional pendulum, and the object to be tested interacts with a magnetic field in a magnetic field environment to generate magnetic torque so that the torsional pendulum is twisted;

the size of the magnetic moment is determined by measuring the change of capacitance between the objective table polar plate and the sensing polar plate, and the magnetic characteristic parameters of the object to be detected are determined according to the magnetic field distribution condition of the magnetic field environment and the size of the magnetic moment, wherein the magnetic characteristic parameters comprise: remanence and magnetic susceptibility.

In an optional example, the determining the magnitude of the magnetic moment by measuring a change in capacitance between the stage plate and the sensing plate specifically includes:

under the condition that the object stage is unloaded, the condition that the object stage is unloaded means that the object to be detected is not placed in the object stage; applying the magnetic field environment to the object stage, wherein the hollow object stage is under the action of magnetic moment in the magnetic field environment, and measuring the magnetic moment of the no-load object stage, wherein the magnetic moment is represented as tau₀；

When the object to be measured is placed in the objective table, the magnetic field environment is applied to the objective table again, and the resultant magnetic moment of the objective table and the object to be measured in the magnetic field environment is measured and expressed as tau_t；

The two measurements are combined, and the object to be measured is subjected to the magnetic moment tau in the magnetic field_mThe object stage and the object to be measured are integrated into a magnetic torque tau_tSubtracting the magnetic moment tau borne by the empty-load stage₀Is obtained, i.e. tau_m＝τ_t-τ₀。

In an optional example, the method further comprises the steps of:

placing a plurality of leveling nuts above the objective table and connecting the leveling nuts with the objective table; the object that the whole that objective table, object to be measured and a plurality of leveling nut constitute is connected as the suspension wire below, a plurality of leveling nut are used for adjusting the equivalent barycenter of suspension wire below connection object, make its equivalent barycenter arrange in on the straight line that the suspension wire belongs to guarantee the steady of twisting pendulum.

In an alternative example, the stage is fabricated from a lightweight material, and the lightweight material is desirably paramagnetic.

In an alternative example, the stage is designed such that the shape and mass of the object to be measured are not limited.

Generally, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

the invention provides a device and a method for measuring the magnetic property of an object, which utilize a high-precision torsion pendulum device and a modulatable magnetic field, can measure the magnetic property of the object which is inconvenient to measure by suspending a light hollow object stage at one end of a suspension wire and placing the object to be measured in the object stage, and can adjust the integral mass center of the object stage and the object to be measured through a leveling nut for the object with an irregular shape, so that the equivalent mass center is placed on a straight line where the suspension wire is positioned, and the stability of torsion pendulum is ensured. The invention realizes the magnetic characteristic measurement of samples with irregular shapes, inconvenient direct suspension and large mass and volume through the hollow objective table and the leveling nut. The invention can realize the measurement of two magnetic characteristics of remanence and magnetic susceptibility on the same device, and avoids the complexity of adopting different instruments for measuring different magnetic characteristics. Meanwhile, due to the design of the object stage of the device, other structures of the device do not need to be modified and reassembled when the sample is replaced, and the step of replacing the sample is greatly simplified.

Drawings

FIG. 1 is a schematic view of a stage structure provided in an embodiment of the present invention;

FIG. 2 is a schematic plan view of a magnetic property measuring apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a magnetic characteristic measuring apparatus according to an embodiment of the present invention;

the same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: the device comprises an object stage 1, a sample to be measured 2, a magnetic field modulation coil 3, a suspension mechanism 4, a leveling nut 5, sensing polar plates 6-13 which are respectively positioned at different positions, an object stage polar plate 14, a measurement and control system 15 and the whole sensing polar plate 16.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention aims to provide a device and a method for measuring the magnetic property of an object, which are used for realizing the research on the measurement of the magnetic property of the object which is inconvenient to hang and has irregular shape or large size.

In one embodiment, the magnetic characteristic device provided by the invention comprises an object stage, a sample to be measured, a magnetic field modulation coil, a suspension mechanism, a leveling nut, a sensing polar plate, an object stage polar plate and a measuring and controlling system. The objective table is made of low-magnetism and light materials. The magnetic field modulation coil can apply currents with different sizes and different directions, and the mounting position can be adjusted.

The technical effects of the invention are as follows: the invention adopts a high-precision torsion pendulum technology to suspend the objective table by using suspension wires with low torsional rigidity, so that the objective table can be freely twisted in the direction of twisting around the suspension wires (Z axis). The object stage and the suspension wire form a single-stage torsional pendulum structure, the structure is in a free state in the direction of twisting around the suspension wire, is extremely sensitive, and can quickly and accurately respond to the acting force applied by the outside in the direction. The objective table is designed by a hollow frame, and an object to be measured with a larger volume and a non-standard shape can be placed on the objective table. The magnetic effect is a bulk effect, and is particularly obvious in performance of a macroscopic object. When currents in different directions are applied to the magnetic field modulation coil, and when the two sides of an object to be detected are placed symmetrically and asymmetrically, different magnetic field environments can be generated in the middle area of the two coils, the object to be detected is in a magnetic field applied by the magnetic field modulation coil, the acting force generates magnetic torque due to the interaction of magnetic characteristics such as remanence and magnetic susceptibility of the object to be detected and the magnetic torque, the magnetic torque is reflected on a torsional pendulum formed by the suspension wire, the objective table and the object to be detected together, the torsional pendulum is stressed to be twisted, and the objective table are integrally and insulated, so that the change of the twisting angle is converted into the change of the capacitance of a polar plate pair formed by the objective table polar plate and the sensing polar plate together.

FIG. 1 is a schematic view of a stage structure provided in an embodiment of the present invention; as shown in fig. 1, the objective table 1 provided by the invention is made of a light and paramagnetic material through hollow processing, the light and hollow structure provides high sensitivity for a torsion pendulum system, and paramagnetism ensures that the objective table can hardly affect the surrounding magnetic field environment. The structure of the objective table provided in the embodiment mainly comprises an upper circular ring, a lower circular ring and four surrounding support rods, wherein the upper circular ring is additionally provided with four screw rods, and the screw rods are respectively and additionally provided with leveling nuts so as to adjust and adjust the equivalent mass center of a connecting object below the suspension mechanism 4, so that the equivalent mass center of the equivalent mass center is arranged on a straight line where suspension wires of the suspension mechanism 4 are arranged, and the stability of torsional pendulum is ensured. The number of the screw rods is more than 2, and the adjusting nut on each screw rod is at least 1, so that the purpose of adjustment can be realized.

The leveling nut 5 is arranged on the object stage 1 and connected with the object stage 1; the torsion pendulum further comprises a plurality of leveling nuts 5; the object table 1, the object to be measured and the leveling nuts 5 are used for adjusting the equivalent mass center of the object connected below the suspension mechanism 4, so that the equivalent mass center is arranged on a straight line where the suspension wire of the suspension mechanism 4 is located, and the stability of torsional pendulum is guaranteed.

Further, the number of the sensor pads is 8, 4 in the X-axis direction, and 4 in the Y-axis direction. The four polar plates on the X axis are arranged in pairs in an opposite mode to form 2 pairs of differential capacitors, the Y axis is the same as the X axis, and 2 pairs of differential capacitors are formed.

Furthermore, the objective plate and the sensing plates on two sides of the objective plate respectively form a plurality of pairs of parallel plate capacitors, and a plurality of pairs of differential capacitors are formed between the plurality of pairs of parallel plate capacitors.

The capacitance value is obtained by the capacitance displacement sensing and feedback system at the back end according to the capacitance and angle transfer function and the angle and force transfer function, and the torsion angle value and the magnetic force value can be calculated in sequence. The relationship between the magnitude of the magnetic force applied to the object in a certain magnetic field and its remanence and magnetic susceptibility can be calculated by the existing mature formula, and will not be described herein.

The measuring and controlling system can measure the torsion and control the translational freedom degree of the objective table, and the translational signal is expressed asAnd 2 pairs of capacitance plates of the Y axis change the capacitance, and the feedback system calculates the translation amount according to the capacitance change and outputs feedback voltage to pull the objective table plates back to the balance position. The feedback system can effectively reduce the disturbance caused by other environmental factors. The measurement of the remanence and the magnetic susceptibility of the sample to be measured in the above way can reach 10 respectively^-9Am²And 10^-7The level of (c).

Further, the feedback part in the capacitance displacement sensing and feedback system can be implemented by designing different types of controllers, such as PID control, embedded EMC control and the like.

Further, the kit is placed in a vacuum chamber.

FIG. 2 is a schematic plan view of a magnetic property measuring apparatus according to an embodiment of the present invention; FIG. 3 is a schematic diagram of a magnetic characteristic measuring apparatus according to an embodiment of the present invention; as shown in fig. 2 and 3, the magnetic characteristic apparatus of the present invention includes: the device comprises an object stage 1, a sample 2 to be measured, a magnetic field modulation coil 3, a suspension mechanism 4, a leveling nut 5, sensing polar plates 6-13, an object stage polar plate 14, a measurement and control system 15 and a whole sensing polar plate 16.

It should be noted that, in the embodiment of the present invention, a magnetic field modulation structure is taken as an example of a magnetic field modulation coil for illustration, and the magnetic field modulation structure used for generating a magnetic field environment for measurement in the present invention is not limited to the magnetic field modulation coil, and may also be other components or devices capable of generating a magnetic field environment, and the present invention does not limit any specific magnetic field modulation structure.

Wherein the displacement stage providing for movement of the magnetic field modulation coil is not shown for ease of illustration. For convenience of describing the embodiment of the present invention, a sample to be tested having a certain shape is placed as an example. But is not limited to this shape sample in practical application.

The invention can be used for researching the magnetic properties of macroscopic objects with different shapes, and the research of the remanence and the magnetic susceptibility of a sample to be tested is taken as an example for explaining the situation.

The lower end objective table 1 is suspended by the suspension mechanism 4, and the suspension mechanism and the lower end objective table 1 form a single-stage torsion pendulum system which is sensitive to the torsion freedom degree in the direction of a suspension wire, and the torsion of the objective table polar plate 14, namely the objective table 1, can be measured with high precision by matching with the sensing polar plate 16 and the measurement and control system 15. Wherein a leveling nut 5 is attached above the object table 1 to adjust the stability of the object table itself. And objective table 1 adopts light and in the same direction as magnetic material fretwork processing preparation, and light and hollow out construction provide high sensitivity for the torsion pendulum system, and paramagnetism has guaranteed that this objective table can accomplish hardly to influence the magnetic field environment on every side to when guaranteeing that magnetic field modulation coil 3 carries out magnetic field modulation, in general precision measurement, this objective table 1's influence can be ignored.

In this embodiment, to ensure high-precision measurement, the magnetic field may be modulated in the no-load state of the stage, and the obtained data is the background data of the apparatus. When an object to be measured is applied to the objective table, magnetic field modulation is carried out again, the obtained data is the response of the sample to be measured and the objective table to the magnetic field, and at the moment, the background data of the objective table is deducted, so that the magnetic characteristic data of the sample to be measured can be obtained.

The pair of magnetic field modulation coils 3 on both sides of the object stage 1 can modulate the magnetic field around the object stage 1, the modulation mode mainly includes a symmetric mode and an asymmetric mode, and three magnetic field configurations can be constructed by applying currents in different directions in the magnetic field modulation coils 3: an axisymmetric magnetic field, a gradient magnetic field, a centrosymmetric magnetic field.

Different magnetic field gradients can be generated around the sample on the objective table 1 through the magnetic field modulation mode, because of the remanence and the magnetic susceptibility of the sample to be detected, the sample to be detected is influenced by the magnetic field gradients, different magnetic acting forces can be generated, specifically, the sample to be detected is rotated by the acting forces, specifically, the sample to be detected is rotated on a single-stage torsion pendulum system formed by the objective table 1 and the suspension mechanism 4, specifically, the torsion pendulum system formed by the objective table 1 at the lower end suspended by the suspension mechanism 4 and the sample to be detected 2 is twisted, the torsion angle quantity is converted into the change of capacitance values between the objective table polar plate 14 at the lower end of the objective table 1 and the capacitance displacement sensing polar plates 6-13, the capacitance change quantity is measured through capacitance displacement sensing, and the position of the capacitance displacement sensing polar plate is controlled and the center of the objective table polar plate frame 14 through the feedback control 0, namely, the position where the differential capacitance is zero, at this time, the static feedback control moment is balanced with the magnetic moment borne by the whole frame, namely the measured magnetic moment of the whole frame in the magnetic field is combined with a magnetic moment calculation formula through the measured magnetic moment, so that the residual magnetism and the magnetic susceptibility of the sample to be measured can be obtained, wherein the magnetic moment calculation formula is a general formula and is not repeated herein.

In the embodiment of the present invention, the stage plate 14 and the plate 8 form a parallel plate capacitor, the stage plate 14 and the plate 9 form another parallel plate capacitor, the difference value of the two parallel plate capacitors is a differential capacitor, the differential capacitor can be measured by the measurement and control system 15, and the position of the stage plate 14 (i.e. the stage 1) between the sensing plates 8 and 9 can be obtained by the magnitude of the differential capacitor. Similarly, for plates 10 and 11, plates 6 and 7, and plates 12 and 13, the position of the stage plate can also be obtained by differential capacitance values. For the measurement of the torsion angle, the difference between the capacitance difference formed by the polar plate 8 and the polar plate 9, and the difference between the two capacitance differences can be converted to obtain the position of the polar plate 14 of the object stage in the four polar plates of 6, 7, 8 and 9, specifically, the position is caused by the torsion of the object stage around the suspension wire, so that the torsion angle value of the object stage can be obtained.

In the embodiment of the invention, a torsion pendulum system formed by suspending the lower end object stage 1 by the suspension mechanism 4 generates translation of two degrees of freedom in the horizontal direction due to environmental disturbance, and the information of the translation is noise information for the measurement, and we need to suppress the translation. Firstly, the translation value is measured, the translation information is represented as the change of capacitance values between the sensing electrode plates 6-13 and the objective table electrode plate 14, the variation is measured by a measurement and control system 15, specifically, the capacitance difference formed by the electrode plate 10 and the electrode plate 11, the capacitance difference formed by the electrode plate 12 and the electrode plate 13, and the sum of the two capacitance differences can be converted to obtain the positions of the objective table electrode plate 14 in the four electrode plates 10, 11, 12 and 13, specifically, the translation information of the objective table, the translation value is captured by the measurement and control system 15, and a response feedback voltage is calculated and applied to the objective table electrode plate 14, and the objective table electrode plate 14 is pulled back to a balance position through an electrostatic driving force generated by a voltage difference, so that the effect of inhibiting the translation of the objective table 1 is achieved.

Due to its extremely high sensitivity, the device needs to be placed in a high vacuum system to reduce the disturbance caused by atmospheric gas molecules and external ambient temperature changes.

In the embodiment of the invention, the sensing polar plate and the objective table polar plate can be made of glass, the sensing polar plate and the objective table polar plate are finely ground to ensure the flatness of the surface, and surface gold plating treatment is carried out to ensure good conductivity of the surface.

In the embodiment of the invention, the suspension wire of the suspension mechanism can be made of quartz wire or tungsten wire.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.