A device and method for automatically detecting residual magnetic field strength of concrete materials

Abstract

The invention relates to the field of magnetic field strength detection technology, and in particular to an automatic detection device and method for residual magnetic field strength of concrete materials; the device comprises: a conveying mechanism, a magnetic shielding mechanism, and a magnetizing mechanism; a plurality of magnetic detection devices are evenly distributed in the magnetic shielding cylinder, the magnetic detection device detects the residual magnetic field strength of a concrete material sample, and a magnetizing component magnetizes the concrete material sample; a control system is used to control the magnetic detection device and the magnetizing mechanism, and calculate the data measured by the magnetic detection device to obtain the residual magnetic field strength of the sample before and after magnetization, and judge whether the detection result exceeds the standard, and display the residual magnetic field strength calculation result on a display; the assembly line type and cyclic automatic detection of the residual magnetic field strength of the concrete material is realized, and the problem of large workload and low detection efficiency of manual detection of a large number of concrete materials is solved; the conveying mechanism adopts non-magnetic material to avoid interference of ferromagnetic material on the detection process.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic field strength detection, and in particular to an automatic detection device and method for residual magnetic field strength of concrete materials. Background Art

[0002] In the fields of astronomical observation, geomagnetic monitoring, precision measurement, geological exploration, etc., it is often necessary to create a non-magnetic or low-magnetic environment to avoid the interference of the environmental magnetic field on precision instruments and measurement results. It is necessary to use non-magnetic or low-magnetic building materials to ensure that the magnetic field interference of the surrounding environment is minimized.

[0003] In actual engineering construction, how to conveniently and accurately detect the magnetism of building raw materials is of great significance to project construction. However, the existing detection methods are rarely used in the measurement of residual magnetic field strength of concrete materials. As a commonly used building material, concrete has a complex composition, including cement, sand, stone, fly ash, mineral powder, silica powder, admixtures, metal materials and components, and the magnetic characteristics of different raw materials are also different. This makes it difficult to quickly and accurately screen and control the magnetism of concrete materials in the production and use process.

[0004] According to the requirements of the engineering project, the residual magnetic field strength of the building materials needs to be controlled within the range of several nT to tens of nT, while the magnetic field strength of the background geomagnetic field is as high as 50,000 nT, which is thousands of times higher than the target magnetic field strength of the building materials. In addition, the electromagnetic interference in the production environment will also have a significant impact on the measurement accuracy, resulting in the inability to accurately distinguish the inherent magnetism of the material and the superposition effect of the external environmental magnetic field during the detection process;

[0005] The industry usually adopts the "secondary detection method", that is, after the first measurement of the residual magnetism of the building material, the material is magnetized by applying an artificial magnetic field, and then its residual magnetic field is tested a second time to evaluate the level of magnetic change of the material. However, there are many types of raw materials involved in concrete structures, including cement, sand, stone, mineral powder and metal components of different grades. The residual magnetic characteristics of each material are different, the detection is difficult, and the screening process is cumbersome. The existing detection method relies on manual detection, with low detection efficiency, and cannot meet the needs of efficient screening and large-scale detection in large-scale projects.

[0006] Therefore, in order to solve the above problems, it is necessary to build an efficient and automated detection system that can accurately detect the residual magnetic field strength of building materials, shield the influence of background geomagnetic field and electromagnetic interference, and support large-scale material screening and efficient detection. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned prior art, the present invention provides a device and method for automatically detecting the residual magnetic field strength of concrete materials, which is capable of performing full-process, assembly-line continuous detection on large quantities of concrete materials in a stable and efficient manner.

[0008] The present invention provides an automatic detection device for residual magnetic field strength of concrete materials, comprising:

[0009] The conveying mechanism comprises a non-magnetic endless conveyor belt, non-magnetic sliding vehicles uniformly arranged on the non-magnetic endless conveyor belt, and a power member driving the non-magnetic endless conveyor belt to rotate, a non-magnetic sample box is placed on the non-magnetic sliding vehicle, a concrete material sample is placed in the non-magnetic sample box, the power member drives the non-magnetic endless conveyor belt to rotate, and the non-magnetic sliding vehicle rotates synchronously with the non-magnetic endless conveyor belt;

[0010] The magnetic shielding mechanism comprises a first support seat and a magnetic shielding cylinder fixed above the first support seat, the magnetic shielding cylinder is open at both ends and is placed horizontally, the non-magnetic annular conveyor belt passes through the magnetic shielding cylinder, and the non-magnetic sliding vehicle and the non-magnetic sample box pass through the magnetic shielding cylinder as the non-magnetic annular conveyor belt rotates;

[0011] A magnetizing mechanism is spaced apart from the magnetic shielding mechanism, comprising a second support seat and a magnetizing assembly fixed above the second support seat, wherein the magnetizing assembly can generate magnetic fields in horizontal and vertical directions, the non-magnetic annular conveyor belt passes through the magnetizing assembly, and the non-magnetic sliding vehicle and the non-magnetic sample box pass through the magnetizing assembly as the non-magnetic annular conveyor belt rotates;

[0012] A plurality of magnetic detection devices are evenly distributed in the magnetic shielding cylinder, the magnetic detection devices detect the magnetic field strength of the concrete material sample, and the magnetizing component magnetizes the concrete material sample;

[0013] A control cabinet includes a display and an internally arranged control system, wherein the control system is used to control the magnetic detection device and the magnetization mechanism, and calculate the data measured by the magnetic detection device to obtain the residual magnetic field strength of the sample before and after magnetization, and judge whether the magnetic field strength detection result exceeds the standard, and display the calculation result of the residual magnetic field strength on the display; and transmit the judgment result to the warning device, and perform corresponding manual disposal according to the signal sent by the warning device.

[0014] In this technical solution, the magnetic shielding mechanism and the magnetizing mechanism are both arranged on a non-magnetic circular conveyor belt. The detection process does not require human intervention, and the streamlined and cyclic automatic detection of the residual magnetic field strength of concrete materials is realized, which solves the problem of large workload and low detection efficiency of manual detection of large quantities of concrete materials, greatly improves work efficiency, and the conveying mechanism uses non-magnetic materials to avoid interference of ferromagnetic materials in the detection process.

[0015] In some embodiments of the present application, the magnetic shielding tube includes a multi-layer shielding layer structure, and a demagnetization coil and a compensation coil are wound between two shielding layers. When the shielding effect of the magnetic shielding tube is weakened, the magnetic shielding tube is demagnetized by the alternating magnetic field generated by the demagnetization coil, and the compensation coil generates a counteracting magnetic field based on the environmental fluctuating magnetic field monitored by the magnetic detection device.

[0016] In some embodiments of the present application, the magnetic shielding tube is a cylindrical structure with a length-to-diameter ratio greater than 2.5:1, the length direction of the magnetic shielding tube is consistent with the length direction of the non-magnetic circular conveyor belt, and the opening of the magnetic shielding tube is placed in the east-west direction, which can not only achieve efficient shielding of the geomagnetic field, but also enable the non-magnetic circular conveyor belt, non-magnetic sliding vehicle, and non-magnetic sample box to pass continuously through the magnetic shielding tube.

[0017] In some embodiments of the present application, the magnetic detection devices are evenly distributed in an annular manner inside the magnetic shielding cylinder, and each of the magnetic detection devices is installed at an equal distance from the surface of the detection sample, so that the multi-axis magnetic field strength of the detection sample can be measured simultaneously to determine the maximum value of the magnetic field strength;

[0018] An environmental magnetic field sensor for measuring the intensity of the environmental magnetic field far away from the sample is also arranged in the magnetic shielding cylinder.

[0019] In some embodiments of the present application, the magnetization assembly includes two groups of horizontal magnetization coils and two groups of vertical magnetization coils, the two groups of vertical magnetization coils are respectively located at the upper end and the lower end of the non-magnetic endless conveyor belt, and are placed parallel to each other in the horizontal direction, and can generate a vertical magnetic field perpendicular to the vertical direction of the non-magnetic endless conveyor belt when energized;

[0020] The two groups of horizontal magnetization coils are respectively located on the left and right sides of the non-magnetic annular conveyor belt, and are placed parallel to each other in the vertical direction. When energized, they can generate a horizontal magnetic field in the horizontal direction perpendicular to the non-magnetic annular conveyor belt;

[0021] The horizontal magnetizing coil and the vertical magnetizing coil can generate a magnetic field required for actual detection by inputting different currents to meet detection requirements.

[0022] In some embodiments of the present application, the horizontal magnetization coil and the vertical magnetization coil are both annular double-beam coils, which use DC pulse magnetization current to generate horizontal magnetic field and vertical magnetic field respectively, with good uniformity, fully simulating the magnetic field environment of the sample.

[0023] In some embodiments of the present application, at least two sample identification systems are provided on the non-magnetic endless conveyor belt, an information identification code containing sample information is affixed to the non-magnetic sample box, and the sample identification system can identify the information identification code and transmit the sample information to the control system;

[0024] The warning device is arranged close to the sample identification system.

[0025] The method for detecting residual magnetic field strength using the above-mentioned automatic detection device for residual magnetic field strength of concrete materials specifically comprises the following steps:

[0026] The concrete material samples are placed in non-magnetic sample boxes, and the information identification codes are respectively attached to the non-magnetic sample boxes;

[0027] The power part drives the non-magnetic annular conveyor belt to rotate at a constant speed, and the non-magnetic sample box rotates synchronously. The sample identification system scans the information identification code on the non-magnetic sample box in turn. Before the non-magnetic sample box enters the magnetic shielding cylinder, each magnetic detection device measures the initial magnetic field strength B of the magnetic shielding cylinder. 0i At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境0 , transmitting it to the control system;

[0028] After the non-magnetic sample box continues to move forward and enters the detection area of ​​the magnetic detection device in the magnetic shielding tube, the non-magnetic annular conveyor belt stops rotating, and each magnetic detection device detects the non-magnetic sample box to obtain the magnetic field strength B of the concrete material sample in different axial directions. 1i At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境1 , transmitting it to the control system;

[0029] The non-magnetic sample box continues to move forward and passes through the magnetic shielding tube, enters the magnetizing mechanism and stops, and the control system controls the magnetizing mechanism to generate a horizontal magnetic field and a vertical magnetic field in turn, and the non-magnetic sample box is magnetized, and then continues to move forward. Before entering the magnetic shielding tube for the second time, each magnetic detection device measures the initial magnetic field strength B of the magnetic shielding tube again. 0i ’ At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境0 ’ , and transmit it to the control system;

[0030] After the non-magnetic sample box continues to move forward and enters the detection area of ​​the magnetic detection device in the magnetic shielding tube, the non-magnetic annular conveyor belt stops rotating, and each magnetic detection device detects the non-magnetic sample box to obtain the magnetic field intensity B of the concrete material sample in different axial directions after magnetization. 1i ’ At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境1 ’ , and transmitted to the control system;

[0031] The non-magnetic sample box continues to move forward, and the control system transmits the residual magnetic field strength result after magnetization to the warning device. When the first non-magnetic sample box continues to move forward to another sample identification system, the warning device displays the test result, and if it is qualified, it will be ready for use; if it is unqualified, it will enter the unqualified product processing process; if the test result is abnormal, manual intervention will be carried out to find out the cause;

[0032] The remaining non-magnetic sample boxes and the above non-magnetic sample box complete the above detection in sequence.

[0033] In some embodiments of the present application, the control system calculates the residual magnetic field strength ΔB before magnetization of the concrete material sample in different axial directions. i , ΔB i =(B 1i -B 环境1 )-(B 0i -B 环境0 );

[0034] Among them, B 1i B is the magnetic field strength of different axial directions of the concrete material sample before magnetization measured by each magnetic detection device; 0i B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the first time; 环境1 The environmental magnetic field sensor and B 1i The ambient magnetic field strength measured at the same time, B 环境0 The environmental magnetic field sensor and B 0i The ambient magnetic field strength measured at the same time;

[0035] Record the maximum value ΔB max , display it on the display and judge whether its value exceeds the standard, wait for the non-magnetic sample box to move to another sample identification system to read the sample information, the control system will judge ΔB i Whether the test result exceeds the standard is warned through the warning device, and the corresponding manual disposal procedure is entered;

[0036] The magnetic field strength B of the concrete material sample in different axial directions after magnetization is obtained. 1i, and transmitted to the control system, the control system calculates the residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions. i ’ , ΔB i ’ =(B 1i ’ -B 环境1 ’ )-(B 0i ’ -B 环境0 ’ );

[0037] Among them, B 1i ’ B is the magnetic field strength of different axial directions of the concrete material sample after magnetization measured by each magnetic detection device; 0i ’ B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the second time; 环境1 ’ The environmental magnetic field sensor and B 1i ’ The ambient magnetic field strength measured at the same time, B 环境0 ’ The environmental magnetic field sensor and B 0i ’ The ambient magnetic field strength measured at the same time.

[0038] Record the maximum value ΔB max ’ , display it on the display and judge whether its value exceeds the standard, wait for the non-magnetic sample box to move to another sample identification system again to read the sample information, the control system will judge ΔB i ’ Whether the test result exceeds the standard, the warning device will issue an alarm again and enter the corresponding manual disposal procedure.

[0039] In some embodiments of the present application, when the magnetic shielding tube completely shields the external environmental magnetic field, the environmental magnetic field intensity measured by the environmental magnetic field sensor is less than or equal to 1nT. At this time, B 环境0 =0,B 环境1 =0,

[0040] The residual magnetic field intensity ΔB of the concrete material sample before magnetization in different axial directions i for

[0041] ΔB i =B 1i -B 0i ,

[0042] The residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for

[0043] ΔB i ’ =B 1i ’ -B 0i ’ ;

[0044] When the ambient magnetic field intensity measured by the ambient magnetic field sensor is greater than 1 nT and less than or equal to 2 nT, at this time,

[0045] The residual magnetic field intensity ΔB of the concrete material sample before magnetization in different axial directions i for

[0046] ΔB i =(B 1i -B 环境1 )-(B 0i -B 环境0 )

[0047] The residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for

[0048] ΔB i ’ =(B 1i ’ -B 环境1 ’ )-(B 0i ’ -B 环境0 ’ );

[0049] When the ambient magnetic field strength measured by the ambient magnetic field sensor is greater than 2 nT, the compensation coil is energized to generate a counteracting magnetic field to eliminate the influence of the ambient magnetic field, so that the ambient magnetic field strength measured by the ambient magnetic field sensor is equal to 0 nT. At this time, B 环境0 =0,B 环境1 =0,

[0050] The residual magnetic field intensity ΔB of the concrete material sample before magnetization in different axial directions i for

[0051] ΔB i =B 1i -B 0i ,

[0052] The residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’for

[0053] ΔB i ’ =B 1i ’ -B 0i ’ ,

[0054] Among them, B 1i B is the magnetic field strength of different axial directions of the concrete material sample before magnetization measured by each magnetic detection device; 0i B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the first time; 环境1 The environmental magnetic field sensor and B 1i The ambient magnetic field strength measured at the same time, B 环境0 The environmental magnetic field sensor and B 0i The ambient magnetic field strength measured at the same time;

[0055] B 1i ’ B is the magnetic field strength of different axial directions of the concrete material sample after magnetization measured by each magnetic detection device; 0i ’ B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the second time; 环境1 ’ The environmental magnetic field sensor and B 1i ’ The ambient magnetic field strength measured at the same time, B 环境0 ’ The environmental magnetic field sensor and B 0i ’ The ambient magnetic field strength measured at the same time.

[0056] Based on the above technical solution, the magnetic shielding mechanism and the magnetizing mechanism are both arranged on the non-magnetic circular conveyor belt. The detection process does not require manual participation, and the streamlining and cyclic automatic detection of the residual magnetic field strength of concrete materials is realized, which solves the problem of large workload and low detection efficiency of manual detection of large quantities of concrete materials, greatly improves the work efficiency, and the conveying mechanism is made of non-magnetic materials to avoid interference of ferromagnetic materials on the detection process;

[0057] The magnetic shielding tube adopts a tunnel-type structure with a high aspect ratio, which can not only effectively shield the interference of the environmental magnetic field, but also realize the continuous conveyance of the samples to be tested by the transmission belt, and apply material magnetic detection in the field of engineering detection, while realizing detection automation;

[0058] The horizontal magnetizing coil and the vertical magnetizing coil are both annular double-beam coils, which use DC pulse magnetizing current to generate horizontal magnetic field and vertical magnetic field respectively. They have good uniformity and fully simulate the magnetic field environment of the sample. Different magnetic field intensities can be generated by adjusting the size of the DC pulse current. The experiment studies the changes in the residual magnetic field strength of the material under different detection parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0060] Figure 1 It is a structural schematic diagram of a device for automatically detecting residual magnetic field strength of concrete materials according to an embodiment of the present invention;

[0061] Figure 2 It is a structural schematic diagram of a magnetic shielding mechanism according to an embodiment of the present invention;

[0062] Figure 3 Schematic diagram of the structure of the magnetization mechanism according to an embodiment of the present invention.

[0063] In the figure:

[0064] 10. Conveying mechanism; 11. Non-magnetic circular conveyor belt; 12. Non-magnetic sliding vehicle; 13. Pneumatic motor; 131. Transmission gear; 14. Non-magnetic sample box; 15. Non-magnetic circular guide rail; 16. Aluminum alloy bracket; 20. Magnetic shielding mechanism; 21. First support seat; 22. Magnetic shielding cylinder; 23. Vector fluxgate sensor; 24. Environmental magnetic field sensor; 30. Magnetization mechanism; 31. Second support seat; 32. Horizontal magnetization coil; 33. Vertical magnetization coil; 40. Control cabinet; 41. Three-color warning light; 42. Scanner for samples to be tested; 43. Scanner for tested samples. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0066] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0067] The terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Thus, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0068] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] As attached Figure 1-Figure 3 As shown in the figure, a concrete material residual magnetic field strength automatic detection device of this embodiment includes:

[0070] The conveying mechanism 10 includes a non-magnetic endless conveyor belt 11, non-magnetic sliding vehicles 12 evenly arranged on the non-magnetic endless conveyor belt 11, and a power member driving the non-magnetic endless conveyor belt 11 to rotate. A non-magnetic sample box 14 is placed on the non-magnetic sliding vehicle 12, and a concrete material sample is placed in the non-magnetic sample box 14. The power member drives the non-magnetic endless conveyor belt 11 to rotate, and the non-magnetic sliding vehicle 12 rotates synchronously with the non-magnetic endless conveyor belt 11. In this embodiment, as Figure 2 As shown, the non-magnetic annular conveyor belt 11 is arranged on the inner side of the non-magnetic annular guide rail 15, and an aluminum alloy bracket 16 is evenly arranged below the non-magnetic annular guide rail 15 for support. The non-magnetic annular conveyor belt 11 is a toothed synchronous transmission belt, and the power part is a pneumatic motor 13 to avoid magnetic interference of ferromagnetic objects and motors on the detection process. In this embodiment, four pneumatic motors 13 are evenly arranged to achieve smooth transmission; the pulley at the bottom of the non-magnetic sliding vehicle 12 moves on the non-magnetic annular guide rail 15;

[0071] The output shaft of the pneumatic motor 13 is connected to the transmission gear 131, the transmission gear 131 is meshed with the non-magnetic annular conveyor belt 11, the pneumatic motor 13 drives the transmission gear 131 to rotate, the transmission gear 131 drives the non-magnetic annular conveyor belt 11 to rotate, and the non-magnetic annular conveyor belt 11 drives the non-magnetic sliding vehicle 12 to move synchronously on the non-magnetic annular guide rail 15;

[0072] The magnetic shielding mechanism 20 includes a first support seat 21 and a magnetic shielding tube 22 fixed above the first support seat 21. The magnetic shielding tube 22 is open at both ends and is placed horizontally in the east-west direction when in use. The non-magnetic annular conveyor belt 11 and the non-magnetic annular guide rail 15 pass through the magnetic shielding tube 22. The non-magnetic sliding vehicle 12 and the non-magnetic sample box 14 pass through the magnetic shielding tube 22 as the non-magnetic annular conveyor belt 11 rotates. Four magnetic detection devices are evenly distributed in the magnetic shielding tube 22. In this embodiment, the magnetic detection device is a vector fluxgate sensor 23 with an accuracy of 0.1nT, which meets the detection requirements of the magnetism of concrete materials. Four vector fluxgate sensors 23 are installed in a surrounding manner in the middle position of the magnetic shielding tube 22. This position has a good magnetic field shielding effect and can effectively shield interfering magnetic fields such as the earth's magnetic field and fluctuating magnetic fields. Each vector fluxgate sensor 23 is 5 cm away from the surface of the non-magnetic sample box 14, and is respectively located above, below, on the left and on the right of the non-magnetic sample box 14. The vector fluxgate sensor 23 located below Figure 2 Not shown in the figure, the multi-axis magnetic field strength of the sample can be detected at one time.

[0073] In addition, an environmental magnetic field sensor 24 for measuring the intensity of the environmental magnetic field away from the sample is also disposed in the magnetic shielding tube 22 of the present embodiment. The environmental magnetic field sensor 24 is also a vector fluxgate sensor.

[0074] In order to accurately determine the position of the non-magnetic sample box 14 in the magnetic shielding tube 22, a position sensing sensor is also provided in the magnetic shielding tube 22; at the same time, in order to accurately measure the magnetic field strength of the concrete material sample, four laser rangefinders are also provided in the magnetic shielding tube 22. The laser rangefinders and the vector fluxgate sensors 23 are arranged one by one, and the laser rangefinder detects the distance between the vector fluxgate sensor 23 and the surface of the non-magnetic sample box 14; when the position sensor detects that the non-magnetic sliding vehicle 12 runs to the detection area of ​​the vector fluxgate sensor 23, the non-magnetic circular conveyor belt 11 stops rotating, and the laser rangefinder detects the distance between the vector fluxgate sensor 23 and the surface of the non-magnetic sample box 14. When the distance is detected to be greater than 5 cm or less than 5 cm, it is necessary to manually adjust the position of the non-magnetic sample box 14 so that the distance between each vector fluxgate sensor 23 and the surface of the non-magnetic sample box 14 is 5 cm.

[0075] In this embodiment, the magnetic shielding tube 22 includes multiple layers of high magnetic permeability Permalloy material as a shielding layer structure. The grade of Permalloy is preferably but not limited to 1J85. The thickness of the Permalloy sheet is 0.5-4mm, preferably 0.8-2mm. The sheet is required to have no obvious defects, and is subjected to demagnetization heat treatment after processing and forming, and has no stress concentration. In order to improve the lightweight and performance, a cylindrical structure is adopted, and the shielding layer has at least three layers, which can effectively shield the external magnetic field; a demagnetization coil and a compensation coil (not shown in the figure) are wound between the two middle shielding layers. When it is detected that the shielding effect of the magnetic shielding tube 22 is weakened, the demagnetization coil is energized to generate an alternating magnetic field to demagnetize the magnetic shielding tube 22, and the compensation coil generates a counteracting magnetic field according to the environmental fluctuation magnetic field passing through the vector fluxgate sensor.

[0076] Furthermore, in this embodiment, the magnetic shielding tube 22 is a cylindrical structure with a length-to-diameter ratio greater than 2.5:1. The length direction of the magnetic shielding tube 22 is consistent with the length direction of the non-magnetic annular conveyor belt 11. The opening of the magnetic shielding tube 22 is placed in the east-west direction, which can not only achieve efficient shielding of the geomagnetic field, but also enable the non-magnetic annular conveyor belt 11, the non-magnetic sliding vehicle 12, and the non-magnetic sample box 14 to pass through the magnetic shielding tube 22 continuously.

[0077] It also includes a magnetizing mechanism 30, which is spaced apart from the magnetic shielding tube 22. In this embodiment, the magnetizing mechanism 30 and the magnetic shielding tube 22 are located at the diagonal position of the non-magnetic annular guide rail 15, and the distance is greater than 10 meters to reduce the influence of the magnetizing mechanism 30 on the magnetic shielding tube 22; Figure 1 As shown, the magnetization mechanism 30 includes a second support seat 31 and a magnetization assembly fixed above the second support seat 31, the non-magnetic annular conveyor belt 11 passes through the magnetization assembly, and the non-magnetic sliding vehicle 12 and the non-magnetic sample box 14 pass through the magnetization assembly as the non-magnetic annular conveyor belt rotates;

[0078] Specifically, Figure 3 As shown, the magnetization assembly includes two groups of horizontal magnetization coils 32 and two groups of vertical magnetization coils 33. The two groups of vertical magnetization coils 33 are respectively located at the upper end and the lower end of the non-magnetic circular conveyor belt 11, and are placed parallel to each other in the horizontal direction. When energized, they can generate a vertical magnetic field in the vertical direction perpendicular to the non-magnetic circular conveyor belt 11; the two groups of horizontal magnetization coils 32 are respectively located on the left and right sides of the non-magnetic circular conveyor belt 11, and are placed parallel to each other in the vertical direction. When energized, they can generate a horizontal magnetic field in the horizontal direction perpendicular to the non-magnetic circular conveyor belt 11;

[0079] The horizontal magnetizing coil 32 and the vertical magnetizing coil 33 are both annular double-beam coils, which use DC pulse magnetizing current to generate horizontal magnetic field and vertical magnetic field respectively, with good uniformity. Compared with the steady magnetic field, they have the advantages of low power consumption, strong magnetic field and less coil heating. By inputting different currents, the magnetizing magnetic field of the required size can be generated, which can be adjusted arbitrarily within 2mT-30mT to meet the detection needs.

[0080] The automated detection device of the present embodiment further comprises a control cabinet 40, on which a display is arranged, and a control system is arranged inside the control cabinet 40, the control system being used to control the magnetic detection device, the magnetization mechanism 30, and calculating the data measured by the four vector fluxgate sensors 23, obtaining the residual magnetic field strength of the sample before and after magnetization, and judging whether the magnetic field strength detection result exceeds the standard, and displaying the calculation result of the residual magnetic field strength on the display; and transmitting the judgment result to the warning device, and performing corresponding manual disposal according to the signal emitted by the warning device; the warning device of the present embodiment is a three-color warning light 41, if the green light of the three-color warning light 41 is on, it indicates that the inspection has been completed and qualified, all inspection work is completed, the non-magnetic sliding vehicle stops moving, and the non-magnetic sample box is manually removed for sample retention; if the red light of the three-color warning light 41 is on, it indicates that the inspection has been completed and unqualified, the non-magnetic sample box is manually removed, and disposed of according to the unqualified product handling procedure; if the yellow light of the three-color warning light 41 is on, it indicates that an abnormal condition has occurred, which cannot be correctly interpreted, and manual intervention is required for investigation.

[0081] In order to improve the automation of the detection process and the efficiency of information transmission, the non-magnetic endless conveyor belt 11 of this embodiment is relatively provided with two QR code scanners for identifying the QR code label containing sample information on the non-magnetic sample box 14, and transmitting the sample information to the control cabinet 40; one of the two QR code scanners is a sample scanner 42 to be tested, which scans and identifies the information of the concrete material sample to be tested that has not passed through the magnetic shielding tube 22, and the other is a tested sample scanner 43, which scans and identifies the sample information that has been measured for magnetic field strength after coming out of the magnetic shielding tube 22. In this embodiment, there are two three-color warning lights 41, which are respectively arranged near the sample scanner 42 to be tested and the tested sample scanner 43.

[0082] On the other hand, the present invention provides a method for detecting residual magnetic field strength using the above-mentioned automatic detection device for residual magnetic field strength of concrete materials, wherein the residual magnetic field strength of the sample is determined by detecting the difference before and after the concrete material sample enters the magnetic shielding tube 22 through four vector fluxgate sensors 23, and the method specifically includes the following steps:

[0083] The concrete material sample is placed in a non-magnetic sample box 14, a QR code label is attached to the non-magnetic sample box 14, and the non-magnetic sample box 14 is placed on a non-magnetic sliding vehicle 12 close to the sample scanner 42 to be tested.

[0084] The pneumatic motor 13 drives the non-magnetic circular conveyor belt 11 to rotate at a constant speed, and the non-magnetic sample box 14 rotates synchronously, and the sample identification system approaches the sample identification system to scan the information identification code on the non-magnetic sample box in sequence. When the first sample to be tested is located at the position sensing sensor of the position sensing sensor, after the position sensing sensor senses the position of the first non-magnetic sample box 14, the sample to be tested scanner 42 automatically scans the QR code identification on the non-magnetic sample box 14, and transmits the concrete material sample information to the control cabinet 40, and the control cabinet 40 determines to perform residual magnetic field strength detection before magnetization;

[0085] The non-magnetic sliding vehicle 12 continues to move clockwise to transport the concrete material sample into the magnetic shielding cylinder 22. Before entering the magnetic shielding cylinder 22, each vector fluxgate sensor 23 measures the initial magnetic field strength B of the magnetic shielding cylinder. 0i (i=1, 2, 3), and the ambient magnetic field intensity measured by the ambient magnetic field sensor 24 is B 环境0 , the measurement results are transmitted to the control system;

[0086] The non-magnetic sliding vehicle 12 continues to move. When the position sensing sensor in the magnetic shielding tube 22 detects that the first non-magnetic sample box has arrived at the detection area, the non-magnetic sliding vehicle 12 and the non-magnetic sample box 14 immediately stop moving. The laser rangefinder records the detection distance between each vector fluxgate sensor 23 and the non-magnetic sample box 14 to ensure that the four vector fluxgate sensors 23 are at the same distance from the sample surface, which is 5 cm in this embodiment. The magnetic field strength B of the concrete material sample in different axes is measured. 1i (i=1, 2, 3), the ambient magnetic field intensity measured by the ambient magnetic field sensor 24 is B 环境1 , the measurement results are transmitted to the control system;

[0087] The control system calculates the residual magnetic field strength ΔB of the concrete material sample before magnetization in different axial directions i , ΔB i =(B 1i -B 环境1 )-(B 0i -B 环境0 ), where i = 1, 2, 3, which is the residual magnetic field strength of the sample before magnetization in different axial directions, where B 1i B is the magnetic field strength of different axial directions of the concrete material sample before magnetization measured by each magnetic detection device; 0i B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the first time; 环境1 The environmental magnetic field sensor and B 1i The ambient magnetic field strength measured at the same time, B 环境0 The environmental magnetic field sensor and B 0iThe ambient magnetic field strength measured at the same time;

[0088] The maximum value of the three sets of data is recorded as ΔB max , display its value on the display and judge whether its value exceeds the standard. When the non-magnetic sample box moves to the position of the measured sample scanner 43, the measured sample scanner 43 reads the QR code sample information, and the control system judges ΔB max Whether the test result exceeds the standard is warned by the three-color warning light 41, and the corresponding manual disposal procedure is entered; if the green light is on, it means that the residual magnetic field strength index before magnetization is qualified, and the non-magnetic sliding vehicle 12 continues to move to the magnetization mechanism 30; if the red light is on, it means that the residual magnetic field strength index before magnetization is unqualified, and the non-magnetic sample box is manually removed and disposed of according to the unqualified product handling procedure; if the yellow light is on, it means that an abnormal situation has occurred and it cannot be correctly interpreted, and manual intervention is required for investigation.

[0089] When the magnetic shielding tube 22 completely shields the external environmental magnetic field, the environmental magnetic field intensity measured by the environmental magnetic field sensor 24 is less than or equal to 1nT. At this time, the environmental magnetic field intensity is negligible, that is, B 环境0 =0,B 环境1 =0, the residual magnetic field intensity ΔB of the concrete material sample before magnetization in different axial directions i for

[0090] ΔB i =B 1i -B 0i ,

[0091] When the ambient magnetic field intensity measured by the ambient magnetic field sensor 24 is greater than 1 nT and less than or equal to 2 nT, at this time, the residual magnetic field intensity ΔB before magnetization of the concrete material sample in different axial directions i for

[0092] ΔB i =(B 1i -B 环境1 )-(B 0i -B 环境0 )

[0093] When the ambient magnetic field intensity measured by the ambient magnetic field sensor 24 is greater than 2 nT, the compensation coil is energized to generate a counteracting magnetic field to eliminate the influence of the ambient magnetic field, so that the ambient magnetic field intensity measured by the ambient magnetic field sensor is equal to 0 nT, that is, B 环境0 =0,B 环境1 =0, at this time, the residual magnetic field intensity ΔB before magnetization of the concrete material sample in different axial directions i for

[0094] ΔB i =B 1i -B 0i

[0095] Among them, B 1i B is the magnetic field strength of different axial directions of the concrete material sample before magnetization measured by each magnetic detection device; 0i B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the first time; 环境1 The environmental magnetic field sensor and B 1i The ambient magnetic field strength measured at the same time, B 环境0 The environmental magnetic field sensor and B 0i The ambient magnetic field strength measured at the same time.

[0096] When the non-magnetic sample box 14 with qualified residual magnetic field strength index before magnetization continues to run until it stops in the magnetization mechanism 30, the control system controls the horizontal magnetization coil 32 to be energized first to generate a horizontal magnetic field, and the vertical magnetization coil 33 to be energized later to generate a vertical magnetic field, with an interval of about 5s, to simulate the magnetic field environment of actual working conditions. After the sample is magnetized, it continues to move forward, and after passing through the sample scanner 42 to be tested, before entering the magnetic shielding tube 22 for the second time, each vector fluxgate sensor 23 measures the magnetic field strength B of the magnetic shielding tube 22 again. 0i ’ (i=1, 2, 3), the ambient magnetic field intensity measured by the ambient magnetic field sensor 24 is B 环境0 ’ , transmitting the measurement results to the control system;

[0097] The non-magnetic sample box 14 continues to move forward and enters the magnetic shielding tube 22. When the position sensing sensor in the magnetic shielding tube 22 detects that the non-magnetic sample box 14 has reached the detection area, the non-magnetic sliding vehicle 12 and the non-magnetic sample box 14 immediately stop moving. The laser rangefinder records that the detection distance between each vector fluxgate sensor 23 and the non-magnetic sample box 14 is the same and is 5 cm. The vector fluxgate sensor 23 detects the non-magnetic sample box to obtain the magnetic field strength B of the concrete material sample in different axes after magnetization. 1i ’ (i=1, 2, 3), the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境1 ’ , transmit the measurement results to the control system;

[0098] The control system calculates the residual magnetic field strength ΔB of the concrete material sample after magnetization in different axial directions i ’ , ΔB i ’ =(B 1i ’ -B 环境1 ’ )-(B 0i’ -B 环境0 ’ ), where i=1, 2, 3, which is the residual magnetic field strength of the sample after magnetization in different axial directions, where B 1i ’ B is the magnetic field strength of different axial directions of the concrete material sample after magnetization measured by each magnetic detection device; 0i ’ B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the second time; 环境1 ’ The environmental magnetic field sensor and B 1i ’ The ambient magnetic field strength measured at the same time, B 环境0 ’ The environmental magnetic field sensor and B 0i ’ The ambient magnetic field strength measured at the same time.

[0099] Record the maximum value of three sets of data ΔB max ’ , and display its value on the display and judge whether its value exceeds the standard. When the non-magnetic sample box 14 moves to the position of the measured sample scanner 43 again, the measured sample scanner 43 reads the QR code sample information, and the control system judges ΔB i ’ Whether the test result exceeds the standard is warned again by the three-color warning light 41, and the corresponding manual disposal procedure is entered; if the green light is on, it means that the test has been completed and qualified, all test work is completed, the non-magnetic sliding car 12 stops moving, and the non-magnetic sample box 14 is manually removed for sampling; if the red light is on, it means that the test has been completed and unqualified, the non-magnetic sample box 14 is manually removed and disposed of according to the unqualified product handling procedure; if the yellow light is on, it means that an abnormal situation has occurred and it cannot be correctly interpreted, and manual intervention is required for investigation.

[0100] When the magnetic shielding tube 22 completely shields the external environmental magnetic field, the environmental magnetic field intensity measured by the environmental magnetic field sensor 24 is less than or equal to 1nT. At this time, the environmental magnetic field intensity is negligible, that is, B 环境0 =0,B 环境1 =0, the residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for

[0101] ΔB i ’ =B 1i ’ -B 0i ’ ;

[0102] When the ambient magnetic field intensity measured by the ambient magnetic field sensor 24 is greater than 1 nT and less than or equal to 2 nT, at this time, the residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for

[0103] ΔB i ’ =(B 1i ’ -B 环境1 ’ )-(B 0i ’ -B 环境0 ’ );

[0104] When the ambient magnetic field intensity measured by the ambient magnetic field sensor 24 is greater than 2 nT, the compensation coil is energized to generate a counteracting magnetic field to eliminate the influence of the ambient magnetic field, so that the ambient magnetic field intensity measured by the ambient magnetic field sensor is equal to 0 nT, that is, B 环境0 =0,B 环境1 =0, at this time, the residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for

[0105] ΔB i ’ =B 1i ’ -B 0i ’ ,

[0106] Among them, B 1i ’ B is the magnetic field strength of different axial directions of the concrete material sample after magnetization measured by each magnetic detection device; 0i ’ B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the second time; 环境1 ’ The environmental magnetic field sensor and B 1i ’ The ambient magnetic field strength measured at the same time, B 环境0 ’ The environmental magnetic field sensor and B 0i ’ The ambient magnetic field strength measured at the same time.

[0107] The remaining non-magnetic sample boxes 14 on the non-magnetic circular conveyor belt 11 and the first non-magnetic sample box complete the above-mentioned detection in sequence.

[0108] Based on the above technical solution, the magnetic shielding mechanism 20 and the magnetizing mechanism 30 are both arranged on the non-magnetic circular conveyor belt 11. The detection process does not require manual participation. Except for the manual labor required for sample handling, other links such as sample transportation, magnetic detection, sample magnetization, and data analysis can be completed automatically, realizing the streamlined and cyclic automatic detection of the residual magnetic field strength of concrete materials, solving the problem of large workload and low detection efficiency of manual detection of large quantities of concrete materials, greatly improving work efficiency, and the conveying mechanism is made of non-magnetic material to avoid interference of ferromagnetic materials on the detection process;

[0109] The magnetic shielding tube 22 adopts a tunnel-type structure with a high aspect ratio, which can effectively shield the interference of the environmental magnetic field and realize the continuous conveyance of the samples to be tested by the transmission belt, and apply material magnetic detection in the field of engineering detection, while realizing detection automation;

[0110] The horizontal magnetizing coil 32 and the vertical magnetizing coil 33 are both annular double-beam coils, which use DC pulse magnetizing current to generate horizontal magnetic field and vertical magnetic field respectively. They have good uniformity and fully simulate the magnetic field environment of the sample. By adjusting the size of the DC pulse current, different magnetic field intensities can be generated. The experiment studies the changes in the residual magnetic field strength of the material under different detection parameters.

[0111] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0112] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. An automatic detection device for residual magnetic field strength of concrete material, characterized by: include: The conveying mechanism comprises a non-magnetic endless conveyor belt, non-magnetic sliding vehicles uniformly arranged on the non-magnetic endless conveyor belt, and a power member driving the non-magnetic endless conveyor belt to rotate, a non-magnetic sample box is placed on the non-magnetic sliding vehicle, a concrete material sample is placed in the non-magnetic sample box, the power member drives the non-magnetic endless conveyor belt to rotate, and the non-magnetic sliding vehicle rotates synchronously with the non-magnetic endless conveyor belt; The magnetic shielding mechanism comprises a first support seat and a magnetic shielding cylinder fixed above the first support seat, the magnetic shielding cylinder is open at both ends and is placed horizontally, the non-magnetic annular conveyor belt passes through the magnetic shielding cylinder, and the non-magnetic sliding vehicle and the non-magnetic sample box pass through the magnetic shielding cylinder as the non-magnetic annular conveyor belt rotates; A magnetizing mechanism is spaced apart from the magnetic shielding mechanism, comprising a second support seat and a magnetizing assembly fixed above the second support seat, wherein the magnetizing assembly can generate magnetic fields in horizontal and vertical directions, the non-magnetic annular conveyor belt passes through the magnetizing assembly, and the non-magnetic sliding vehicle and the non-magnetic sample box pass through the magnetizing assembly as the non-magnetic annular conveyor belt rotates; A plurality of magnetic detection devices are evenly distributed in the magnetic shielding cylinder, the magnetic detection devices detect the magnetic field strength of the concrete material sample, and the magnetizing component magnetizes the concrete material sample; A control cabinet includes a display and an internally arranged control system, wherein the control system is used to control the magnetic detection device and the magnetization mechanism, and calculate the data measured by the magnetic detection device to obtain the residual magnetic field strength of the sample before and after magnetization, and judge whether the magnetic field strength detection result exceeds the standard, and display the calculation result of the residual magnetic field strength on the display; and transmit the judgment result to the warning device, and perform corresponding manual disposal according to the signal sent by the warning device.

2. The automatic detection device for residual magnetic field strength of concrete material according to claim 1 is characterized in that: The magnetic shielding tube includes a multi-layer shielding layer structure, with a demagnetization coil and a compensation coil wound between two shielding layers. When the shielding effect of the magnetic shielding tube is weakened, the magnetic shielding tube is demagnetized by the alternating magnetic field generated by the demagnetization coil, and the compensation coil generates a counteracting magnetic field based on the environmental fluctuating magnetic field monitored by the magnetic detection device.

3. The automatic detection device for residual magnetic field strength of concrete material according to claim 2 is characterized in that: The magnetic shielding tube is a cylindrical structure with a length-to-diameter ratio greater than 2.5:

1. The length direction of the magnetic shielding tube is consistent with the length direction of the non-magnetic circular conveyor belt. The opening of the magnetic shielding tube is placed in the east-west direction, which can not only achieve efficient shielding of the geomagnetic field, but also enable the non-magnetic circular conveyor belt, non-magnetic sliding vehicle, and non-magnetic sample box to pass through the magnetic shielding tube continuously.

4. The automatic detection device for residual magnetic field strength of concrete material according to claim 1, characterized in that: The magnetic detection devices are evenly distributed in an annular manner inside the magnetic shielding cylinder, and each of the magnetic detection devices is installed at an equal distance from the surface of the detection sample, and the multi-axis magnetic field strength of the detection sample is measured at the same time to determine the maximum value of the magnetic field strength; An environmental magnetic field sensor for measuring the intensity of the environmental magnetic field far away from the sample is also arranged in the magnetic shielding cylinder.

5. The automatic detection device for residual magnetic field strength of concrete material according to claim 1, characterized in that: The magnetization assembly includes two groups of horizontal magnetization coils and two groups of vertical magnetization coils. The two groups of vertical magnetization coils are respectively located at the upper end and the lower end of the non-magnetic endless conveyor belt, and are placed parallel to each other in the horizontal direction. When energized, they can generate a vertical magnetic field perpendicular to the vertical direction of the non-magnetic endless conveyor belt. The two groups of horizontal magnetization coils are respectively located on the left and right sides of the non-magnetic annular conveyor belt, and are placed parallel to each other in the vertical direction. When energized, they can generate a horizontal magnetic field in the horizontal direction perpendicular to the non-magnetic annular conveyor belt; The horizontal magnetization coil and the vertical magnetization coil can generate magnetic fields required for actual detection by inputting different currents.

6. The automatic detection device for residual magnetic field strength of concrete material according to claim 5, characterized in that: The horizontal magnetizing coil and the vertical magnetizing coil are both annular double-beam coils, which use DC pulse magnetizing current to generate horizontal magnetic field and vertical magnetic field respectively, have good uniformity, and fully simulate the magnetic field environment of the sample.

7. The automatic detection device for residual magnetic field strength of concrete material according to claim 1, characterized in that: At least two sample identification systems are arranged on the non-magnetic endless conveyor belt, an information identification code containing sample information is affixed to the non-magnetic sample box, and the sample identification system can identify the information identification code and transmit the sample information to the control system; The warning device is arranged close to the sample identification system.

8. A method for automatically detecting residual magnetic field strength of concrete material, implemented using the device according to any one of claims 1 to 7, characterized in that: The specific steps include: The concrete material samples are placed in non-magnetic sample boxes, and the information identification codes are respectively attached to the non-magnetic sample boxes; The power part drives the non-magnetic annular conveyor belt to rotate at a constant speed, and the non-magnetic sample box rotates synchronously. The sample identification system scans the information identification code on the non-magnetic sample box in turn. Before the first non-magnetic sample box enters the magnetic shielding cylinder, each magnetic detection device measures the initial magnetic field strength B of the magnetic shielding cylinder. 0i At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境0 , transmitting it to the control system; After the non-magnetic sample box continues to move forward and enters the detection area of ​​the magnetic detection device in the magnetic shielding tube, the non-magnetic annular conveyor belt stops rotating, and each magnetic detection device detects the non-magnetic sample box to obtain the magnetic field strength B of the concrete material sample in different axial directions. 1i At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境1 , transmitting it to the control system; The non-magnetic sample box continues to move forward and passes through the magnetic shielding tube, enters the magnetizing mechanism and stops, and the control system controls the magnetizing mechanism to generate a horizontal magnetic field and a vertical magnetic field in turn, and the non-magnetic sample box is magnetized, and then continues to move forward. Before entering the magnetic shielding tube for the second time, each magnetic detection device measures the initial magnetic field strength B of the magnetic shielding tube again. 0i ’ At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境0 ’ , and transmit it to the control system; After the non-magnetic sample box continues to move forward and enters the detection area of ​​the magnetic detection device in the magnetic shielding tube, the non-magnetic annular conveyor belt stops rotating, and each magnetic detection device detects the non-magnetic sample box to obtain the magnetic field intensity B of the concrete material sample in different axial directions after magnetization. 1i ’ At this time, the ambient magnetic field intensity measured by the ambient magnetic field sensor is B 环境1 ’ , and transmitted to the control system; The non-magnetic sample box continues to move forward, and the control system transmits the residual magnetic field strength result after magnetization to the warning device. When the non-magnetic sample box continues to move forward to another sample identification system, the warning device displays the test result and is qualified for use; If it is unqualified, it will enter the unqualified product processing process; If the test result is abnormal, manual intervention is required to investigate the cause; The remaining non-magnetic sample boxes and the above non-magnetic sample box complete the above detection in sequence.

9. The method for automatically detecting residual magnetic field strength of concrete material according to claim 8, characterized in that: The control system calculates the residual magnetic field strength ΔB before magnetization of the concrete material sample in different axial directions i , ΔB i =(B 1i -B 环境1 )-(B 0i -B 环境0 ); Among them, B 1i B is the magnetic field strength of different axial directions of the concrete material sample before magnetization measured by each magnetic detection device; 0i B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the first time; 环境1 The environmental magnetic field sensor and B 1i The ambient magnetic field strength measured at the same time, B 环境0 The environmental magnetic field sensor and B 0i The ambient magnetic field strength measured at the same time; Record the maximum value ΔB max , display it on the display and judge whether its value exceeds the standard, wait for the non-magnetic sample box to move to another sample identification system to read the sample information, the control system will judge ΔB i Whether the test result exceeds the standard is warned through the warning device, and the corresponding manual disposal procedure is entered; The magnetic field strength B of the concrete material sample in different axial directions after magnetization is obtained. 1i , and transmitted to the control system, the control system calculates the residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions. i ’ , ΔB i ’ =(B 1i ’ -B 环境1 ’ )-(B 0i ’ -B 环境0 ’ ); Among them, B 1i ’ B is the magnetic field strength of different axial directions of the concrete material sample after magnetization measured by each magnetic detection device; 0i ’ B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the second time; 环境1 ’ The environmental magnetic field sensor and B 1i ’ The ambient magnetic field strength measured at the same time, B 环境0 ’ The environmental magnetic field sensor and B 0i ’ The ambient magnetic field strength measured at the same time; Record the maximum value ΔB max ’ , display it on the display and judge whether its value exceeds the standard, wait for the non-magnetic sample box to move to another sample identification system again to read the sample information, the control system will judge ΔB i ’ Whether the test result exceeds the standard, the warning device will issue an alarm again and enter the corresponding manual disposal procedure.

10. The method for automatic detection of residual magnetic field strength of concrete material according to claim 9, characterized in that: When the magnetic shielding tube completely shields the external environmental magnetic field, the environmental magnetic field intensity measured by the environmental magnetic field sensor is less than or equal to 1nT. 环境0 =0,B 环境1 =0, The residual magnetic field intensity ΔB of the concrete material sample before magnetization in different axial directions i for: ΔB i =B 1i -B 0i , The residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for ΔB i ’ =B 1i ’ -B 0i ’ ; When the ambient magnetic field intensity measured by the ambient magnetic field sensor is greater than 1 nT and less than or equal to 2 nT, at this time, The residual magnetic field intensity ΔB of the concrete material sample before magnetization in different axial directions i for ΔB i =(B 1i -B 环境1 )-(B 0i -B 环境0 ) The residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for ΔB i ’ =(B 1i ’ -B 环境1 ’ )-(B 0i ’ -B 环境0 ’ ); When the ambient magnetic field strength measured by the ambient magnetic field sensor is greater than 2 nT, the compensation coil is energized to generate a counteracting magnetic field to eliminate the influence of the ambient magnetic field, so that the ambient magnetic field strength measured by the ambient magnetic field sensor is equal to 0 nT. At this time, B 环境0 =0,B 环境1 =0, The residual magnetic field intensity ΔB of the concrete material sample before magnetization in different axial directions i for ΔB i =B 1i -B 0i , The residual magnetic field intensity ΔB of the concrete material sample after magnetization in different axial directions i ’ for ΔB i ’ =B 1i ’ -B 0i ’ , Among them, B 1i B is the magnetic field strength of different axial directions of the concrete material sample before magnetization measured by each magnetic detection device; 0i The initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the first time; B 环境1 The environmental magnetic field sensor and B 1i The ambient magnetic field strength measured at the same time, B 环境0 The environmental magnetic field sensor and B 0i The ambient magnetic field strength measured at the same time; B 1i ’ B is the magnetic field strength of different axial directions of the concrete material sample after magnetization measured by each magnetic detection device; 0i ’ B is the initial magnetic field strength of the magnetic shielding cylinder measured by each magnetic detection device before the concrete material sample enters the magnetic shielding cylinder for the second time; 环境1 ’ The environmental magnetic field sensor and B 1i ’ The ambient magnetic field strength measured at the same time, B 环境0 ’ The environmental magnetic field sensor and B 0i ’ The ambient magnetic field strength measured at the same time.

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