A support positioning device for zero magnetic device performance evaluation

Abstract

The present invention discloses a support and positioning device for zero magnetic device performance evaluation, characterized in that it includes a magnetic shielding room floor, a sliding bracket base, and a sliding bracket. The magnetic shielding room floor is provided with four groups of centrally symmetrical threaded holes. The four corners of the sliding bracket base are provided with legs, and the four legs are fixedly mounted on a central positioning mounting plate. The four central positioning mounting plates are fixed on the magnetic shielding room floor by bolts and threaded holes, so that the four central positioning mounting plates are centrally symmetrical. The support device is fixed to the reserved mounting hole on the magnetic shielding room floor by the central positioning mounting plate, so that the support device can be accurately placed in the central area of ​​the magnetic shielding room. Compared with the original scheme, there is an accurate positioning standard; (2) The support device can realize the integrated function of sensor calibration and measurement.

Description

Technical Field

[0001] The invention relates to the field of zero-magnetic device performance evaluation, and more specifically to a supporting and positioning device used for zero-magnetic device performance evaluation. Background Art

[0002] The shielding layer of the passive magnetic shielding device, i.e. the magnetic shielding room, is mainly made of Permalloy, a highly magnetically conductive material. Permalloy, as a soft magnetic material, is easily magnetized under the action of an external magnetic field. The residual static magnetic field of the external interference magnetic field after being shielded by the shielding room and the magnetization magnetic field of the soft magnetic material together constitute the residual static magnetic field inside the magnetic shielding room. The residual static magnetic field is one of the important evaluation indicators of the performance of the magnetic shielding room, and its precise measurement is of great significance to the construction of the shielding room and the construction of the evaluation system.

[0003] When performing distributed measurement of the static magnetic field in the central area of ​​a magnetic shielding room, we need a device to carry the magnetic sensor and achieve precise positioning in space. The existing carrying device has the following disadvantages:

[0004] (1) The zero bias calibration function of the magnetic sensor cannot be realized;

[0005] (2) The bracket cannot be accurately placed in the center area of ​​the zero magnetic chamber;

[0006] (3) The clamping fixture is fixed in position and can only collect magnetic field signals at specific points;

[0007] (4) The clamping tool uses 6 bolts to clamp the sensor. Each installation and removal is very cumbersome and time-consuming. In the process of tightening the sensor with 6 bolts, it is difficult to ensure the consistency of the screw-in length of the bolts, thus making it difficult to ensure the consistency of the sensor's direction and posture. Summary of the invention

[0008] In view of the shortcomings of the existing technology, we proposed a multifunctional evaluation device that can realize arbitrary positioning, facilitate sensor installation and disassembly, and integrate calibration and measurement.

[0009] The technical solution of the present invention is as follows:

[0010] A supporting positioning device for zero magnetic device performance evaluation, comprising a magnetic shielding room floor, a sliding bracket base, and a sliding bracket, wherein the magnetic shielding room floor is provided with four groups of centrally symmetrical threaded hole positions, the four corners of the sliding bracket base are provided with supporting feet, the four supporting feet are fixedly mounted on a central positioning mounting plate, and the four central positioning mounting plates are fixed on the magnetic shielding room floor by bolts and threaded hole positions, so that the four central positioning mounting plates are centrally symmetrical;

[0011] The sliding bracket base includes an upper and lower layer, a calibration fixture installation platform is installed at the middle position of the lower layer of the sliding bracket base, and a sensor zero bias calibration fixture is installed on the calibration fixture installation platform; slide grooves are provided on both sides of the sliding bracket base, and the sliding bracket is slidably matched with the slide grooves, a center guide rail is provided at the middle position of the upper layer of the sliding bracket base, and a pulley is provided at the bottom in the middle of the sliding bracket, and the pulley is slidably matched with the center guide rail; a scale label ruler and a main measurement point positioning hole are provided on the upper surface of the upper layer of the sliding bracket base, and the main measurement point positioning hole matches the positioning angle piece installed on the side of the sliding bracket, and is locked by a positioning locking bolt;

[0012] The sliding bracket is provided with multiple sensor quick loading and unloading mechanisms, which are used to install fluxgate sensors. The multiple sensor quick loading and unloading mechanisms are arranged in a 3x3 array on one side of the sliding bracket; the sensor quick loading and unloading mechanisms include a clamping tool, a pin, and a slot. The slot is fixed to the side of the sliding bracket. The pin is Z-shaped, one end of the pin is embedded in the hole corresponding to the slot, and the other end of the pin is embedded in the side of the clamping tool and fixed by bolts.

[0013] The inner wall of the sliding bracket is provided with a raised sliding support convex strip, and the support convex strip is embedded in the sliding grooves provided on the two sides of the sliding bracket base;

[0014] The positions of the main measuring point positioning holes are located at the following positions of the scale label ruler: 0 point, 1 / 4 point, 1 / 2 point, 3 / 4 point, and 1 point.

[0015] A locking bolt is provided on the side of the slot. When the bayonet is inserted into the slot, the locking bolt is turned to achieve locking.

[0016] The clamping tool has an opening on the top for inserting the fluxgate sensor. The clamping tool also includes a side limit surface, a lower limit surface and a front limit surface.

[0017] An atomic magnetic clamping tool is installed on the other side of the sliding bracket.

[0018] The sliding brackets can be provided in three numbers, and are slidably provided at the left, middle and right positions on the sliding bracket base.

[0019] The whole body is made of engineering plastics and resin materials, and the bolts are made of nylon materials. These are non-magnetic materials to avoid introducing interfering magnetic fields.

[0020] Technical effects and advantages of the present invention:

[0021] (1) This bracket device is fixed to the reserved mounting hole on the floor of the magnetic shielding room through the central positioning mounting plate, so that the bracket device can be accurately placed in the center area of ​​the magnetic shielding room. (Compared with the original solution, there is a precise positioning standard)

[0022] (2) This bracket device can realize the integrated functions of sensor calibration and measurement.

[0023] (3) This bracket device adopts a linear guide structure with a slider and a slide slot, equipped with a scale ruler, which can realize positioning measurement at any position in the x direction; (the original solution can only measure fixed points)

[0024] (4) The sensor's quick loading and unloading mechanism saves installation time and process, enables quick loading and unloading of the sensor, and the clamping tool can well ensure the direction and posture of the sensor.

[0025] (5) This bracket is a multifunctional bracket with abundant reserved mounting holes. It can measure the residual static magnetic field by installing a fluxgate sensor, measure the noise index of the magnetic shielding room by installing an atomic magnetometer, and measure the shielding coefficient by using an external coil. In short, this bracket can play a role in the test of the three indicators of the residual static magnetic field, magnetic noise and shielding coefficient of the shielding room.

[0026] (6) It can greatly improve the test efficiency. When there are enough sensors, if 9 sets of sensors are used at the same time, the sliding bracket can be moved as a whole to measure 9 points at a time. Compared with the sensors moving one by one, the measurement efficiency can be greatly improved.

[0027] (7) If there are enough sensors, for example, if there are 27 sets of sensors working at the same time, 3 sliding brackets can be set, which can accurately measure and evaluate the uniformity of the magnetic field in the three directions of x, y, and z in the central area, and can also evaluate the magnetic field gradient index in the central area. Even if there are not so many sensors, if there are 9 (for example), they can be moved from the left to the middle and then to the right, and the magnetic field uniformity and gradient index can still be evaluated, but there is no standard for simultaneous evaluation of 27 sets of sensors, because the time factor changes during the movement, and the magnetic field will also change. However, the magnetic field inside the magnetic shielding room is very stable, that is, the change in a short period of time is extremely small, so when the number of sensors is small, it is also possible to ignore the time factor and evaluate the magnetic field uniformity and gradient.

[0028] (8) The base of the sliding bracket adopts a solid wooden structure, and the sliding bracket adopts hollow engineering plastics and resin, with the center of gravity at the bottom, which is more stable. The bolts are made of nylon. The above materials are all non-magnetic materials, which can avoid the introduction of interfering magnetic fields.

[0029] (9) Advantage of quick installation: The existing technology uses six bolts to lock the transposition installation of the sensor. The locking process takes a long time, and the length of the bolts screwed in is different, which affects the direction and posture of the sensor. This solution uses a quick-release Z-shaped pin inserted into the slot to achieve transposition installation, which can improve the efficiency by more than 3 times, and the direction and posture of the sensor remain consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the sliding bracket base and the sliding bracket structure;

[0032] Figure 3 This is a schematic diagram of the structure of the magnetic shielding room floor;

[0033] Figure 4 This is a schematic diagram of the structure of the calibration fixture installation platform;

[0034] Figure 5 for Figure 1 Schematic diagram of the structure inside the middle and large circle;

[0035] Figure 6 It is a schematic diagram of the structure of the sliding bracket base;

[0036] Figure 7 for Figure 1 Schematic diagram of the structure inside the small and medium circles;

[0037] Figure 8 and Fig. 9 It is a partial schematic diagram of the sensor quick loading and unloading mechanism;

[0038] Fig.10 Schematic diagram of the card slot structure;

[0039] Fig.11 This is a schematic diagram of the sliding bracket structure. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Embodiment 1

[0042] like Figure 1-11As shown, a supporting positioning device for zero magnetic device performance evaluation includes a magnetic shielding room floor 1, a sliding bracket base 2, and a sliding bracket 3. The magnetic shielding room floor is provided with 4 groups of centrally symmetrical threaded hole positions 11, each group of threaded hole positions includes 5 threaded holes, and the four corners of the sliding bracket base are provided with supporting legs 21, and the four supporting legs are fixedly mounted on a central positioning mounting plate 22. The four central positioning mounting plates are fixed on the magnetic shielding room floor by bolts and threaded hole positions, so that the four central positioning mounting plates are centrally symmetrical;

[0043] The sliding bracket base 2 includes two layers, an upper layer and an lower layer, a calibration fixture installation platform 4 is installed in the middle of the lower layer of the sliding bracket base, and a sensor zero bias calibration fixture 5 is installed on the calibration fixture installation platform 4; the two side surfaces of the sliding bracket base 2 are provided with slide grooves 23, and the sliding bracket is slidably matched with the slide grooves, and a central guide rail 24 is provided in the middle of the upper layer of the sliding bracket base, and a pulley is provided at the bottom in the middle of the sliding bracket, and the pulley is slidably matched with the central guide rail; the upper surface of the upper layer of the sliding bracket base is provided with a scale label ruler 25 and a main measurement point positioning hole 26, and the main measurement point positioning hole matches the positioning angle piece 33 installed on the side of the sliding bracket, and is locked by a positioning locking bolt;

[0044] The sliding bracket is provided with a plurality of sensor quick loading and unloading mechanisms 6, which are used to install a fluxgate sensor 61, and the plurality of sensor quick loading and unloading mechanisms are arranged in a 3x3 array on one side of the sliding bracket; the sensor quick loading and unloading mechanism includes a clamping tool 62, a bayonet 63, and a slot 64, wherein the slot 64 is fixed to the side of the sliding bracket 3, and the bayonet is Z-shaped, with one end of the bayonet 63 embedded in a hole a corresponding to the slot, and the other end of the bayonet is embedded in the side of the clamping tool and fixed by bolts.

[0045] The inner wall 3 of the sliding bracket is provided with a raised sliding support ridge 34, and the support ridge is embedded in the sliding grooves 23 provided on the two sides of the sliding bracket base;

[0046] The positions of the main measuring point positioning holes are located at the following positions of the scale label ruler: 0 point, 1 / 4 point, 1 / 2 point, 3 / 4 point, and 1 point.

[0047] A locking bolt 65 is provided on the side of the slot. When the bayonet is inserted into the slot, the locking bolt is screwed to achieve locking.

[0048] The clamping tool 62 has an opening on its top for inserting the fluxgate sensor. The clamping tool also includes a side limit surface 621 , a lower limit surface 622 and a front limit surface 623 .

[0049] An atomic magnetic clamping tool 7 is installed on the other side of the sliding bracket, and the atomic magnetic clamping tool 7 is arranged in a 3x3 array.

[0050] Implementation column 2

[0051] Main functional details and innovations

[0052] (1) Detail 1: Design of center positioning function

[0053] 1) In order to make the measuring points accurately distributed in the central area of ​​the internal space of the magnetic shielding room, make full use of the four pairs of reserved threaded holes symmetrically on the floor of the magnetic shielding room, and fix the four center positioning mounting plates on the floor of the magnetic shielding room by bolts, so that the four center positioning mounting plates are symmetrical.

[0054] 2) Place the four legs of the bracket base in the square holes reserved on the center positioning mounting plate, and then securely connect them using the bracket base fixings.

[0055] Through the above two-step design, the measuring bracket can be located in the center area of ​​the magnetic shielding room in the horizontal direction.

[0056] 3) In the vertical direction, the measurement point can be located in the center of the magnetic shielding room by designing the height of the sliding bracket base, the height of the sliding bracket, and the size of the mounting hole position.

[0057] Problem to be solved: The existing bracket cannot be accurately located in the central area of ​​the magnetic shielding room in the horizontal direction (the existing bracket is placed in the center of the shielding room by visual inspection in the experiment).

[0058] (2) Detail 2: Integrated design of sensor calibration and magnetic field measurement

[0059] A magnetic sensor calibration platform is designed using the space below the sliding bracket, which can realize the integrated functions of magnetic sensor calibration and data acquisition. That is, after the magnetic sensor is calibrated at the bottom of the sliding bracket base, it can be installed on the sliding bracket to carry out the work of the residual static magnetic field.

[0060] Problem solved: When there is no calibration platform, the bracket needs to be moved to the shielding room after calibration, which is a complicated process. The integrated design of calibration and measurement facilitates the operation process of residual static magnetic field evaluation.

[0061] (3) Detail 3: Positioning function at any position

[0062] 1) The sliding bracket slides in the guide rail (slide groove) using its own sliding support structure. It can slide to any measuring position according to the value of the scale label and be locked in place by tightening the positioning locking bolts on both sides.

[0063] 2) For the key measuring points in the center area: 0 point, 1 / 4 point, 1 / 2 point, 3 / 4 point, 1 point, during the machining process, the position accuracy of the threaded holes can reach ±0.2mm; bolt connections are used to connect the angle pieces to achieve precise positioning and locking of the sliding bracket at the key measuring points (main measuring points).

[0064] Problem solved: The original device can only fix the clamping tool in a limited specified position and cannot realize the positioning measurement at any position. This solution can realize the positioning and locking at any position, as well as the precise positioning and locking of the key measurement points of concern, and realize the precise measurement of the magnetic field at any position and key positions.

[0065] (4) Detail 4: Sensor quick loading and unloading mechanism

[0066] The function of the quick loading and unloading mechanism is realized in the following ways: 1) Install the card slot on the sliding bracket; 2) Install the sensor on the clamping tool; 3) Use the card pin to clamp the sensor clamping tool together with the sensor into the card slot. The card slot and the card pin are closely matched in size, and the fixed locking function is basically realized; 4) When the sensor needs to be repositioned, pull out the card pin, and switch it from card slot 1 to card slot 2 (or other corresponding card slots) to achieve quick loading and unloading; 5) The locking threaded hole is used to lock the card pin and the card slot with bolts, which is used when the sensor does not need to be repositioned or requires tightening.

[0067] In addition, the five limit surfaces limit the six degrees of freedom of the sensor through processing precision and the threaded fixation of the threaded mounting hole of the touch sensor, ensuring that it is horizontal and vertical after installation, and the position and posture remain unchanged.

[0068] Note: This device is very useful when there are a small number of sensors that need to be constantly repositioned for measurement, saving a lot of loading and unloading time.

[0069] Problems solved: 1) In the original measuring device, when the sensor needs to be repositioned, the sensor needs to be moved and the touch sensor needs to be fastened with 6 bolts, which is time-consuming and labor-intensive. This solution can achieve rapid repositioning through the plug-in installation of the bayonet and the slot. 2) In the original design, the clamping and positioning of the sensor relies on the tightening of 6 bolts, and during the tightening process, it is difficult to ensure that the position and posture of the sensor remain unchanged (the tightening lengths of the 6 bolts are different, and the direction and posture of the sensor will be skewed). This solution can ensure that the orientation and posture of the sensor remain unchanged through the limiting surface, the positioning of the sensor mounting bolts, and the tight positioning of the slot and the bayonet, greatly reducing the error caused by the sensor direction and posture to the measurement result.

[0070] (5) Other beneficial functions

[0071] 1) A large number of slot installation holes are reserved on the horizontal and vertical beams of the sliding bracket, which can realize the magnetic field measurement of more measurement points in the y and z directions.

[0072] 2) One side of the sliding bracket is reserved for the installation hole of the fluxgate sensor clamping tool, and the other side is reserved for the installation hole of the atomic magnetic force clamping tool. The fluxgate sensor can measure the residual static magnetic field, which is a performance evaluation index of the magnetic shielding room, while the atomic magnetism can measure another performance evaluation index of the magnetic shielding room, the magnetic field noise. In conjunction with the coil outside the magnetic shielding room (this is more complicated to explain, and there is no detailed explanation without drawing a picture), the "shielding coefficient" index can also be measured. So this bracket is actually a multi-functional bracket.

[0073] 3) Since the bracket device is relatively high, in order to ensure the stability of the device, the center of gravity needs to be moved downward; therefore, the sliding bracket base adopts a solid structure, and the sliding bracket as a whole adopts a hollow (weight-removing) structure to achieve the overall downward shift of the center of gravity to ensure its stability.

[0074] 4) The vertical rod of the sliding bracket adopts a slot structure, which has two advantages: first, it is easy to assemble; second, the four limiting surfaces of the slot can realize the limiting of two degrees of freedom, making the sliding bracket more stable.

[0075] 5) The design of the wheel is mainly to play a certain supporting role. Since the span of the bracket is large, it prevents the bracket from bending and deformation. The friction between the wheel and the base of the sliding bracket is rolling friction, and the friction force is small; if the vertical beam support is directly used, the friction is sliding friction, and the friction force is large.

[0076] 6) The base of the sliding bracket adopts a solid wooden structure, and the sliding bracket adopts hollow engineering plastics and resin, with the center of gravity at the bottom, which is more stable.

[0077] Embodiment 3

[0078] Related technical knowledge:

[0079] (I) Magnetic shielding room and shielding principle (popular science background knowledge)

[0080] (1) Zero magnetic environment: refers to an environment where the magnetic field strength is zero.

[0081] (2) (Passive) magnetic shielding device: A device that can shield the interference of the environmental magnetic field, thereby forming a near-zero magnetic field environment in its internal space. Large (passive) magnetic shielding devices are often called "magnetic shielding rooms", and small (passive) magnetic shielding devices are often called "magnetic shielding cylinders".

[0082] (3) Passive magnetic shielding principle:

[0083] 1) Ferromagnetic shielding: Utilize the magnetic circuit shunting effect of highly permeable materials to shield static magnetic fields. When the shielding material is in a static magnetic field, according to the "Ampere's circuit theorem" and the "magnetic flux continuity theorem", the magnetic field strength and magnetic induction strength need to suddenly change direction at the interface between two different media. This shielding structure allows the magnetic induction strength outside the shielding body to be transferred to the shielding surface, and then is shunted one by one inside the shielding material in a direction parallel to its surface, and finally flows out of the shielding material without entering the inside of the shielding body.

[0084] 2) Eddy current shielding. The induced eddy current effect of highly conductive materials is used to shield the alternating magnetic field. When the shielding material is in a time-varying magnetic field, according to "Faraday's law of electromagnetic induction", the electric field generated by the time-varying magnetic field will generate a changing induced current inside the conductive material, and then generate a changing induced magnetic field. The induced magnetic field and the external magnetic field repel each other, preventing the external magnetic field from entering the shielded area.

[0085] (II) Performance evaluation indicators of magnetic shielding rooms (popular science background knowledge)

[0086] The main evaluation indicators of the magnetic shielding room are: shielding coefficient, residual static magnetic field and magnetic noise.

[0087] (1) Magnetic shielding coefficient. It is expressed as the ratio of the magnetic field strength at the center of the magnetic shielding room to the strength of the magnetic field at the center of the magnetic shielding room when there is a magnetic shielding room or not.

[0088] (2) Residual static magnetic field: Residual static magnetic field refers to the residual magnetic induction intensity or magnetic field intensity value inside the magnetic shielding room after being shielded by the magnetic shielding room.

[0089] (3) Magnetic field noise. After the interference signal is shielded in a magnetic shielding room, the value of the residual magnetic field interference signal distributed with frequency is usually expressed by power spectrum density or amplitude spectrum density in a specific frequency domain.

[0090] (III) Evaluation method of residual static magnetic field

[0091] (1) Evaluation method

[0092] The residual static magnetic field of the magnetic shielding room is generally evaluated by the static magnetic field in the central area of ​​a certain range of the magnetic shielding room. The side length of the central area of ​​the cube is about 1 / 3 of the side length of the magnetic shielding room space.

[0093] (2) Test operation method

[0094] The central area of ​​the cube is divided into an array of n×n×n measuring points. A magnetic sensor is used to collect the residual static magnetic field at each measuring point. 3 The maximum value of each point is the residual static magnetic field value of the magnetic shielding room, that is:

[0095] B static =max(Bi )

[0096] In the formula, i=1…n.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A support and positioning device for zero magnetic device performance evaluation, Features: It includes a magnetic shielding room floor, a sliding bracket base and a sliding bracket, wherein the magnetic shielding room floor is provided with four groups of centrally symmetrical threaded holes, the four corners of the sliding bracket base are provided with legs, the four legs are fixedly mounted on a central positioning mounting plate, and the four central positioning mounting plates are fixed on the magnetic shielding room floor by bolts and threaded holes, so that the four central positioning mounting plates are centrally symmetrical; The sliding bracket base includes an upper and lower layer, a calibration fixture installation platform is installed at the middle position of the lower layer of the sliding bracket base, and a sensor zero bias calibration fixture is installed on the calibration fixture installation platform; slide grooves are provided on both side surfaces of the sliding bracket base, and the sliding bracket is slidably matched with the slide grooves; a center guide rail is provided at the middle position of the upper layer of the sliding bracket base, and a pulley is provided at the bottom in the middle of the sliding bracket, and the pulley is slidably matched with the center guide rail; a scale label ruler and a main measurement point positioning hole are provided on the upper surface of the upper layer of the sliding bracket base, and the main measurement point positioning hole matches the positioning angle piece installed on the inner side of the sliding bracket, and is locked by a positioning locking bolt; The sliding bracket is provided with multiple sensor quick loading and unloading mechanisms, which are used to install fluxgate sensors. The multiple sensor quick loading and unloading mechanisms are arranged in a 3x3 array on the back of the sliding bracket; the sensor quick loading and unloading mechanisms include a clamping tool, a pin, and a slot. The slot is fixed to the back of the sliding bracket. The pin is Z-shaped, one end of the pin is embedded in the hole corresponding to the slot, and the other end of the pin is embedded in the side of the clamping tool and fixed by bolts.

2. A supporting and positioning device for zero magnetic device performance evaluation according to claim 1, Features: The inner wall of the sliding bracket is provided with a raised sliding support convex strip, and the support convex strip is embedded in the sliding grooves provided on the two side surfaces of the sliding bracket base.

3. A supporting and positioning device for zero magnetic device performance evaluation according to claim 1, Features: The positions of the main measuring point positioning holes are located at the following positions of the scale label ruler: 0 point, 1 / 4 point, 1 / 2 point, 3 / 4 point, and 1 point.

4. A supporting and positioning device for zero magnetic device performance evaluation according to claim 1, Features: A locking bolt is provided on the side of the slot. When the bayonet is inserted into the slot, the locking bolt is turned to achieve locking.

5. A supporting and positioning device for zero magnetic device performance evaluation according to claim 1, Features: The clamping tool has an opening on the top for inserting the fluxgate sensor. The clamping tool also includes a side limit surface, a lower limit surface and a front limit surface.

6. A supporting and positioning device for zero magnetic device performance evaluation according to claim 1, Features: An atomic magnetic clamping tool is installed on the other side of the sliding bracket.

7. A supporting and positioning device for zero magnetic device performance evaluation according to claim 1, Features: The sliding brackets are provided in three numbers, and are slidably provided at the left, middle and right positions on the sliding bracket base.

8. A supporting and positioning device for zero magnetic device performance evaluation according to claim 1, Features: The base of the sliding bracket adopts a solid wooden structure, and the sliding bracket adopts hollow engineering plastics and resin, with the center of gravity at the bottom, which is more stable.

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