Permanent magnet steel magnetism monitoring system

Abstract

The invention discloses a permanent magnet steel magnetism monitoring system, belongs to the technical field of magnetism monitoring devices, and particularly relates to a permanent magnet steel magnetism monitoring system. The device comprises a speed sensor, magnetic steel and a magnetic monitoring module. The magnetic monitoring module is sleeved outside the magnetic steel, a clamping spring for limiting is arranged outside the magnetic monitoring module, and a limiting clamping groove for mounting the clamping spring is formed in the surface of the mounting groove; a mounting groove is formed in the end part of the speed sensor, and the magnetic steel is arranged in the mounting groove and upwards forms a convex part; and the magnetic monitoring module is mounted in the mounting groove, sleeves the magnetic steel, and is limited and fixed by matching a snap spring with a limiting clamping groove in the surface of the mounting groove. The magnetic monitoring module is composed of a shell, a Hall detector and the like, the Hall detector measures magnetism of magnetic steel, an iron-nickel alloy cover shields an external magnetic field, a temperature sensor measures temperature, and a controller controls heating to prevent low-temperature errors. The module is installed on a speed sensor through a snap spring and a limiting clamping groove, magnetic steel can be directly detected, and disassembly-free detection is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic monitoring devices, and in particular relates to a permanent magnetic steel magnetic monitoring system. Background Art

[0002] In the field of modern electromagnetism, magnetic field strength, as a key physical quantity that describes the strength of a magnetic field, plays an extremely important role in various electromagnetic experiments. However, the magnetic field is a special substance that is invisible and intangible, which poses a great challenge to the accurate measurement of magnetic field strength and is difficult to measure directly.

[0003] In many practical application scenarios, magnets play an irreplaceable role. Taking speed sensors as an example, magnets play a core role in such sensors. Its primary function is to provide a stable and reliable magnetic field environment, work closely with the sensor, detect the dynamic changes of the magnetic field, and accurately output the speed signal. In this process, the presence of magnets not only significantly improves the accuracy of the sensor, making the speed measurement more accurate, but also greatly enhances the reliability of the sensor, reduces the measurement errors caused by various interference factors, and effectively extends the durability of the sensor and reduces the maintenance cost of the equipment. Based on these advantages, magnets in speed sensors are widely used in the automotive industry to provide key data support for vehicle speed monitoring and control systems; in the industrial field, they help the precise operation and automatic control of various mechanical equipment; in the energy industry, they ensure the stable operation of power generation equipment, power transmission and distribution equipment, etc.

[0004] However, it cannot be ignored that with the increase of usage time and the complexity and changeability of the working environment, the magnetic steel in the speed sensor will inevitably experience magnetic degradation. Magnetic degradation will seriously affect the accuracy of the speed sensor, and thus have a negative impact on the normal operation of the entire system. Therefore, in order to ensure that the speed sensor always maintains high-precision operation, long-term and effective monitoring of the magnetic steel is particularly necessary.

[0005] At present, traditional equipment has obvious drawbacks when monitoring magnetic steel. The monitoring process often requires repeated clamping operations on the magnetic steel. Every time the magnetic steel is disassembled and reinstalled, due to human factors in the operation process and the limitations of the mechanical structure, it is very easy to cause deviations in the installation angle of the magnetic steel. Even a slight deviation in the installation angle will cause the position of the magnetic steel to change, and the change in the position of the magnetic steel will directly introduce measurement errors, which greatly reduces the accuracy of the monitoring data. This measurement error not only affects the accurate evaluation of the actual performance of the magnetic steel, but may also lead to a series of subsequent problems caused by misjudgment. Therefore, the development of a permanent magnetic steel magnetic monitoring system that can avoid measurement errors caused by repeated clamping has become an important issue that needs to be solved urgently. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention provides a permanent magnet magnetic monitoring system.

[0007] A permanent magnet magnetic monitoring system includes a speed sensor, a magnet, and a magnetic monitoring module; the magnetic monitoring module is sleeved outside the magnet, a snap ring for limiting is arranged outside the magnetic monitoring module, and a limiting groove for installing the snap ring is opened on the surface of the installation groove; an installation groove is provided at the end of the speed sensor, the magnet is placed in the installation groove and forms a convex part upward; the magnetic monitoring module is installed in the installation groove and sleeved outside the magnet, and is limited and fixed by the cooperation of the snap ring and the limiting groove on the surface of the installation groove;

[0008] The magnetic monitoring module is composed of a housing, a Hall detector, an iron-nickel alloy cover, a temperature sensor, a controller, and an electric heating carbon fiber mesh; the Hall detector is installed in the housing, the iron-nickel alloy cover is arranged outside the housing, the temperature sensor is also arranged in the housing, the controller and the electric heating carbon fiber mesh are installed in the housing, and the electric heating carbon fiber mesh is located between the Hall detector and the iron-nickel alloy cover.

[0009] Further, the snap ring is located at the end of the housing.

[0010] Further, the installation depth error of the snap ring is controlled within ±0.1 mm.

[0011] Further, the measurement range of the Hall detector is 0 - 30 kGs, and the accuracy is ±0.5%.

[0012] Further, the shielding effectiveness of the iron-nickel alloy cover is not less than 60 dB.

[0013] Further, the housing is concentric with the magnet.

[0014] Further, a processing module and a digital-to-analog conversion module are installed in the housing, the digital-to-analog conversion module is electrically connected to the Hall detector, and the processing module is electrically connected to the digital-to-analog conversion module, the temperature sensor, and the controller.

[0015] Further, the housing is composed of a hollow ring and a hollow circular plate, the middle parts of the iron-nickel alloy cover and the electric heating carbon fiber mesh are both located in the hollow circular plate of the housing, and the edges of the iron-nickel alloy cover and the electric heating carbon fiber mesh are both located in the hollow ring of the housing.

[0016] Further, the electric heating carbon fiber mesh is located between the Hall detector and the iron-nickel alloy cover, and its middle part is located in the hollow circular plate and the edge is located in the hollow ring.

[0017] Further, the temperature sensors are distributed in a circular array in the housing.

[0018] Advantages of the present invention:

[0019] The present invention relates to a magnetic monitoring module composed of a housing, a Hall detector, a Fe-Ni alloy cover, a temperature sensor, a controller, and an electrically heated carbon fiber mesh. The Hall detector is used to monitor the magnetism of the permanent magnet, and the Fe-Ni alloy cover is used to shield the external magnetic field, reducing the external influence on the Hall detector when monitoring the magnetism of the permanent magnet. The temperature sensor is used to monitor the temperature of the magnetic monitoring module, and the controller is used to control the electrically heated carbon fiber mesh to heat the magnetic monitoring module, thereby avoiding the problem of errors in the magnetic monitoring of the permanent magnet due to low temperature in winter. The magnetic monitoring module is clamped in the installation groove provided at the end of the speed sensor through the cooperation of a snap ring and a limit card slot, and the magnetic monitoring module is sleeved outside the permanent magnet, facilitating the magnetic monitoring module to monitor the magnetism of the permanent magnet, enabling the magnetic monitoring module to directly monitor the magnetism of the permanent magnet on the speed sensor, and solving the problem that the permanent magnet needs to be disassembled for magnetic detection. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a permanent magnet magnetic monitoring system;

[0021] Figure 2 It is an exploded structural diagram of a permanent magnet magnetic monitoring system;

[0022] Figure 3 It is a three-dimensional sectional schematic diagram of a permanent magnet magnetic monitoring system;

[0023] Figure 4 It is a front sectional schematic diagram of a permanent magnet magnetic monitoring system;

[0024] Figure 5 It is Figure 4 The enlarged view at position A in

[0025] Figure 6 It is the change curve of the magnetic properties of the NdFeB magnet over time;

[0026] Figure 7 It is the change curve of the magnetic properties of the SmCo magnet over time;

[0027] Figure 8 It is the change curve of the magnetic properties of the NdFeB magnet over temperature;

[0028] Figure 9 It is the change curve of the magnetic properties of the SmCo magnet over time. Detailed Embodiments

[0029] Specific Embodiment 1: This embodiment will be described in conjunction with the accompanying drawings. A permanent magnet magnetic monitoring system in this embodiment includes a speed sensor 1, a magnet 3, and a magnetic monitoring module 6. The magnetic monitoring module 6 is sleeved outside the magnet 3, and a circlip 7 for limiting is arranged outside the magnetic monitoring module 6. A limiting card slot 5 for installing the circlip 7 is opened on the surface of the installation groove 2. An installation groove 2 is provided at the end of the speed sensor 1, the magnet 3 is placed in the installation groove 2, and a convex part 4 is formed upward. The magnetic monitoring module 6 is installed in the installation groove 2, sleeved outside the magnet 3, and is limited and fixed by the cooperation of the circlip 7 and the limiting card slot 5 on the surface of the installation groove 2.

[0030] The magnetic monitoring module 6 is composed of a housing 61, a Hall detector 62, an iron-nickel alloy cover 63, a temperature sensor 66, a controller 67, and an electric heating carbon fiber mesh 68. The Hall detector 62 is installed inside the housing 61, an iron-nickel alloy cover 63 is arranged outside the housing 61, the temperature sensor 66 is also arranged inside the housing 61, the controller 67 and the electric heating carbon fiber mesh 68 are installed inside the housing 61, and the electric heating carbon fiber mesh 68 is located between the Hall detector 62 and the iron-nickel alloy cover 63.

[0031] In this embodiment, the speed sensor 1, the magnet 3, the magnetic monitoring module 6, the circlip 7, and the limiting card slot 5 form a stable assembly structure. Through the cooperation of the circlip 7 and the limiting card slot 5, the magnetic monitoring module 6 is firmly sleeved outside the magnet 3 and installed in the installation groove 2 of the speed sensor 1, ensuring the relative position between the monitoring module and the magnet 3 is fixed, and guaranteeing the monitoring stability and accuracy. The structure of the housing 61 and the layout of each internal component are reasonable. For example, the positional relationship between the iron-nickel alloy cover 63 and the electric heating carbon fiber mesh 68 and the housing 61 not only ensures the realization of the magnetic shielding and heating functions but also makes each component compact and orderly, reducing mutual interference and ensuring the stable operation of the system.

[0032] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that the circlip 7 is located at the end of the housing 61. Others are the same as Specific Embodiment 1.

[0033] Specific Embodiment 3: The difference between this embodiment and Specific Embodiment 1 is that the installation depth error of the circlip 7 is controlled within ±0.1 mm. Others are the same as Specific Embodiment 1.

[0034] Specific Embodiment 4: The difference between this embodiment and Specific Embodiment 1 is that the measurement range of the Hall detector 62 is 0 - 30 kGs, and the accuracy is ±0.5%. Others are the same as Specific Embodiment 1.

[0035] Specific Embodiment 5: The difference between this embodiment and Specific Embodiment 1 is that the shielding effectiveness of the iron-nickel alloy cover 63 is 60 dB. Others are the same as Specific Embodiment 1.

[0036] In this embodiment, the iron-nickel alloy cover 63 has a magnetic shielding function, which can reduce the interference of the external magnetic field on the Hall detector 62. When there is a complex magnetic field in the external environment, the iron-nickel alloy cover 63 shields the interfering magnetic field outside, enabling the Hall detector 62 to more accurately sense the magnetic field of the magnet 3 itself and improving the monitoring accuracy.

[0037] Specific Embodiment Six: The difference between this embodiment and Specific Embodiment One is that the housing 61 is concentric with the magnet 3. Others are the same as Specific Embodiment One.

[0038] Specific Embodiment Seven: The difference between this embodiment and Specific Embodiment One is that a processing module 64 and a digital-to-analog conversion module 65 are installed in the housing 61. The digital-to-analog conversion module 65 is electrically connected to the Hall detector 62, and the processing module 64 is electrically connected to the digital-to-analog conversion module 65, the temperature sensor 66, and the controller 67. Others are the same as Specific Embodiment One.

[0039] In this embodiment, the Hall detector 62 monitors the magnetism of the magnet 3 and works in coordination with the digital-to-analog conversion module 65 and the processing module 64. The Hall detector 62 obtains the magnetic data of the magnet 3, the digital-to-analog conversion module 65 converts it into a digital signal, and the processing module 64 can output accurate magnetic monitoring results after processing, realizing the effective monitoring of the magnetism of the magnet 3.

[0040] Specific Embodiment Eight: The difference between this embodiment and Specific Embodiment One is that the housing 61 is composed of a hollow ring and a hollow circular plate. The middle parts of the iron-nickel alloy cover 63 and the electrically heated carbon fiber mesh 68 are both located within the hollow circular plate of the housing 61, and the edges of the iron-nickel alloy cover 63 and the electrically heated carbon fiber mesh 68 are both located within the hollow ring of the housing 61. Others are the same as Specific Embodiment One.

[0041] Specific Embodiment Nine: The difference between this embodiment and Specific Embodiment One is that the electrically heated carbon fiber mesh 68 is located between the Hall detector 62 and the iron-nickel alloy cover 63, with its middle part within the hollow circular plate and its edge within the hollow ring. Others are the same as Specific Embodiment One.

[0042] Specific Embodiment Ten: The difference between this embodiment and Specific Embodiment One is that the temperature sensors 66 are distributed in a circular array within the housing 61. Others are the same as Specific Embodiment One.

[0043] In this embodiment, the temperature sensor 66, the controller 67, and the electrically heated carbon fiber mesh 68 work together to deal with low temperatures. The temperature sensor 66 monitors the temperature of the magnetic monitoring module 6 in real time. When the temperature drops to the set threshold, it transmits a signal to the processing module 64, and the processing module 64 controls the controller 67 to start heating the electrically heated carbon fiber mesh 68 to avoid magnetic monitoring errors caused by low temperatures.

[0044] The following embodiments are used to verify the technical effects of the present invention:

[0045] A permanent magnet magnetic monitoring system includes a speed sensor 1, a magnet 3, and a magnetic monitoring module 6; the magnetic monitoring module 6 is sleeved outside the magnet 3, a snap ring 7 for limiting is arranged outside the magnetic monitoring module 6, and a limiting slot 5 for installing the snap ring 7 is opened on the surface of the installation groove 2; an installation groove 2 is provided at the end of the speed sensor 1, the magnet 3 is placed in the installation groove 2 and forms a convex part 4 upward; the magnetic monitoring module 6 is installed in the installation groove 2, sleeved outside the magnet 3, and is limited and fixed by the cooperation of the snap ring 7 and the limiting slot 5 on the surface of the installation groove 2;

[0046] The magnetic monitoring module 6 is composed of a housing 61, a Hall detector 62, an iron-nickel alloy cover 63, a temperature sensor 66, a controller 67, and an electrothermal carbon fiber net 68; the Hall detector 62 is installed in the housing 61, an iron-nickel alloy cover 63 is arranged on the outside of the housing 61, the temperature sensor 66 is also arranged in the housing 61, the controller 67 and the electrothermal carbon fiber net 68 are installed in the housing 61, and the electrothermal carbon fiber net 68 is located between the Hall detector 62 and the iron-nickel alloy cover 63;

[0047] The snap ring 7 is located at the end of the housing 61; the installation depth error of the snap ring 7 is controlled within ±0.1 mm; the measurement range of the Hall detector 62 is 0 - 30 kGs, and the accuracy is ±0.5%; the shielding effectiveness of the iron-nickel alloy cover 63 is 60 dB; the housing 61 is concentric with the magnet 3; a processing module 64 and a digital-to-analog conversion module 65 are installed in the housing 61, the digital-to-analog conversion module 65 is electrically connected to the Hall detector 62, and the processing module 64 is electrically connected to the digital-to-analog conversion module 65, the temperature sensor 66, and the controller 67; the housing 61 is composed of a hollow ring and a hollow circular plate, the middle parts of the iron-nickel alloy cover 63 and the electrothermal carbon fiber net 68 are both located in the hollow circular plate of the housing 61, and the edges of the iron-nickel alloy cover 63 and the electrothermal carbon fiber net 68 are both located in the hollow ring of the housing 61; the electrothermal carbon fiber net 68 is located between the Hall detector 62 and the iron-nickel alloy cover 63, with its middle part located in the hollow circular plate and its edge located in the hollow ring; the temperature sensors 66 are distributed in a circular array in the housing 61.

[0048] Embodiment 1: I. The test steps for the evolution law of magnetic properties over time are as follows:

[0049] Magnet preparation: The NdFeB magnet is cut into a cylinder with a diameter of φ10 * 10 mm by wire electrical discharge machining, and the surface of the magnet is polished with sandpaper to remove the oxide layer and make the magnet surface bright;

[0050] Pre-installation Preparation: Before installation, prepare the magnetic monitoring module, snap ring 7, special tools (such as snap ring pliers) and supporting cables, and check whether the installation groove 2 and the limit card slot 5 of the speed sensor 1 are clean and free of deformation. Ensure that the operating environment is free of strong magnetic field interference to avoid affecting the initial calibration of the Hall detector 62. At the same time, verify whether the protruding part 4 of the magnet 3 is centered in the installation groove 2 to provide basic conditions for subsequent installation;

[0051] Installation of Magnetic Monitoring Module: Align the housing 61 of the magnetic monitoring module 6 with the installation groove 2 so that its hollow ring completely covers the protruding part 4 of the magnet 3, and gently press the housing 61 so that its bottom surface fits with the installation groove 2. Use snap ring pliers to embed the snap ring 7 into the limit card slot 5 to ensure that the housing 61 is fixed and concentric with the magnet 3, avoiding measurement errors caused by installation angle deviation;

[0052] Electrical Connection and System Startup: Connect the power supply lines of the processing module 64 and the controller 67 to an external power supply system (such as a 12V DC power supply), and connect the output end of the digital-to-analog conversion module 65 to an external monitoring device. After power-on, the processing module 64 automatically executes a self-check program: check whether the signal of the Hall detector 62 is normal and whether the initial temperature value of the temperature sensor 66 is reasonable. If the self-check passes, the system enters the standby mode; if it is abnormal, the circuit needs to be checked or the module needs to be recalibrated.

[0053] Magnetic Monitoring and Temperature Regulation: The Hall detector 62 continuously collects the analog signal of the magnetic field intensity of the magnet 3. After being converted into a digital signal by the digital-to-analog conversion module 65, the processing module 64 performs filtering and compensation calculations and outputs magnetic state parameters. The temperature sensor 66 continuously monitors the internal temperature of the housing 61. Set the housing temperature to 25°C. If the detected temperature is 1°C lower than the preset temperature, the processing module 64 starts the electric heating carbon fiber mesh 68 to heat through the controller 67 until the temperature returns to the normal range.

[0054] Embodiment 2: The difference between this embodiment and Embodiment 1 is that an SmCo magnet is used in Step 1. Others are the same as Embodiment 1.

[0055] From Figure 6 and Figure 7 it can be seen that the surface magnetic fields of both the NdFeB magnet and the SmCo magnet gradually decrease with the passage of time, and the rate of decrease in magnetic field strength gradually slows down with the passage of time. Comparing the magnetic property attenuation amounts of the two magnets, the attenuation rate of the NdFeB magnet is higher than that of the SmCo, and its magnetic stability is relatively poor.

[0056] Embodiment 3: The test steps for the evolution law of magnetic properties with temperature are as follows:

[0057] Magnet Preparation: Cut the NdFeB magnet into a cylinder of φ10*10mm by wire electrical discharge machining, and use sandpaper to polish the magnet surface to remove the oxide layer, making the magnet surface shiny;

[0058] Preparation before Installation: Before installation, it is necessary to prepare a magnetic monitoring module, a circlip 7, special tools (such as a circlip pliers) and supporting cables, and check whether the installation groove 2 and the limit card slot 5 of the speed sensor 1 are clean and free of deformation. Ensure that the operating environment is free from strong magnetic field interference to avoid affecting the initial calibration of the Hall detector 62. At the same time, verify whether the protruding part 4 of the magnet 3 is centered in the installation groove 2 to provide the basic conditions for subsequent installation:

[0059] Installation of Magnetic Monitoring Module: Align the housing 61 of the magnetic monitoring module 6 with the installation groove 2 so that its hollow ring completely covers the protruding part 4 of the magnet 3, and gently press the housing 61 so that its bottom surface fits with the installation groove 2. Use a circlip pliers to embed the circlip 7 into the limit card slot 5 to ensure that the housing 61 is fixed and concentric with the magnet 3, avoiding measurement errors caused by installation angle deviation;

[0060] Electrical Connection and System Startup: Connect the power supply lines of the processing module 64 and the controller 67 to an external power supply system (such as a 12V DC power supply), and connect the output end of the digital-to-analog conversion module 65 to an external monitoring device. After power-on, the processing module 64 automatically executes a self-check program: check whether the signal of the Hall detector 62 is normal and whether the initial temperature value of the temperature sensor 66 is reasonable. If the self-check passes, the system enters the standby mode; if it is abnormal, it is necessary to check the circuit or recalibrate the module;

[0061] Magnetic Monitoring and Temperature Regulation: The Hall detector 62 continuously collects the analog signal of the magnetic field intensity of the magnet 3. After being converted into a digital signal by the digital-to-analog conversion module 65, the processing module 64 performs filtering and compensation calculations and outputs the magnetic state parameters. Set the housing temperature to 30°C, read the magnetic field intensity value after the temperature stabilizes, raise the temperature to 40°C, and read the value after the temperature stabilizes, and so on until the temperature reaches 100°C to obtain the variation law of the magnetic field intensity at different temperatures.

[0062] Example 4: The difference between this example and Example 3 is that in step one, a SmCo magnet is used. Others are the same as in Example 1.

[0063] From Figure 8 and Figure 9 it can be seen that as the ambient temperature rises, the magnetic field on the magnet surface gradually decreases, and there is an approximately linear relationship between the magnetic field intensity and the temperature. Comparing the surface magnetic field decay rates of the two magnets, it can be seen that the SmCo magnet has better thermal stability than the NdFeB magnet.

Claims

1. A permanent magnet magnetic steel magnetic monitoring system, characterized in that The permanent magnetic steel magnetic monitoring system comprises a speed sensor (1), a magnetic steel (3) and a magnetic monitoring module (6); the magnetic monitoring module (6) is sleeved on the outside of the magnetic steel (3), a retaining spring (7) for limiting is arranged on the outside of the magnetic monitoring module (6), and a limiting clamping groove (5) for installing the retaining spring (7) is opened on the surface of the mounting groove (2); the speed sensor (1) is provided with a mounting groove (2) at the end, the magnetic steel (3) is placed in the mounting groove (2), and a protrusion (4) is formed upward; the magnetic monitoring module (6) is installed in the mounting groove (2), sleeved on the outside of the magnetic steel (3), and the retaining spring (7) cooperates with the limiting clamping groove (5) on the surface of the mounting groove (2) to limit and fix; The magnetic monitoring module (6) is composed of a shell (61), a Hall detector (62), an iron-nickel alloy cover (63), a temperature sensor (66), a controller (67) and an electrically heated carbon fiber net (68); the shell (61) is provided with a Hall detector (62), the outer side of the shell (61) is provided with an iron-nickel alloy cover (63), the shell (61) is further provided with a temperature sensor (66), the shell (61) is provided with a controller (67) and an electrically heated carbon fiber net (68), and the electrically heated carbon fiber net (68) is located between the Hall detector (62) and the iron-nickel alloy cover (63).

2. A permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The clamping spring (7) is located at the end of the housing (61).

3. A permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The installation depth error of the clamping spring (7) is controlled within ±0.1 mm.

4. A permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The measurement range of the Hall sensor (62) is 0-30 kGs, and the accuracy is ±0.5%.

5. The permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The shielding effectiveness of the iron-nickel alloy cover (63) is not less than 60 dB.

6. A permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The housing (61) is concentric with the magnetic steel (3).

7. A permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that A processing module (64) and a digital-to-analog conversion module (65) are installed in the housing (61); the digital-to-analog conversion module (65) is electrically connected to the Hall detector (62); and the processing module (64) is electrically connected to the digital-to-analog conversion module (65), a temperature sensor (66) and a controller (67).

8. The permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The shell (61) is composed of a hollow circular ring and a hollow circular plate, the middle parts of the iron-nickel alloy cover (63) and the electrically heated carbon fiber net (68) are both located in the hollow circular plate of the shell (61), and the edges of the iron-nickel alloy cover (63) and the electrically heated carbon fiber net (68) are both located in the hollow circular ring of the shell (61).

9. A permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The electrically heated carbon fiber mesh (68) is located between the Hall sensor (62) and the iron-nickel alloy cover (63), with the middle portion located in the hollow circular plate and the edge located in the hollow circular ring.

10. A permanent magnet magnetic steel magnetic monitoring system according to claim 1, characterized in that The temperature sensors (66) are distributed in a ring array inside the housing (61).

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