Underwater array AC electromagnetic field crack detection probe device and system

Abstract

The present invention provides an underwater array type AC electromagnetic field crack detection probe device and system, wherein the device comprises: a shell; the shell is filled with insulating oil; the shell has two vertical first and second ends; the first end of the shell is provided with a sensor cover; the sensor cover is provided with a detection module and a mounting seat, the detection module comprises a data acquisition module and an excitation module; the data acquisition module comprises an acquisition chip set; the excitation module comprises an I-type magnetic core and an excitation coil; the I-type magnetic core is placed in the groove of the mounting seat, and the excitation coil is wound around the I-type magnetic core; the acquisition chip is provided on one side of the lower end face of the mounting seat and on the end face facing away from the I-type magnetic core; the second end of the shell is provided with a connector. The present invention can realize crack detection of metal structures with coatings on the surface in a deep water environment, and can realize detection of cracks with complex orientations.

Description

Technical Field

[0001] The present invention relates to the technical field of alternating current electromagnetic field detection, and in particular to an underwater array type alternating current electromagnetic field crack detection probe device and system. Background Art

[0002] Alternating Current Field Measurement (ACFM) is an emerging electromagnetic nondestructive testing technology with unique advantages such as non-contact, little influence by workpiece material, and no need for calibration. Its principle is: the excitation probe induces a uniform alternating current on the surface of the workpiece to be tested. When there is a crack, the current bypasses the sides and bottom of the crack, causing surface electromagnetic field disturbances. The electromagnetic field signal is recorded and analyzed and processed to obtain the size information describing the crack state, thereby achieving the purpose of quantitative analysis.

[0003] At present, relevant research has been conducted in China on ACFM technology, but it is generally about the application of ACFM detection technology on land. There is relatively little research on ACFM technology underwater detection probes. In addition, due to the technical characteristics of electromagnetic signal acquisition of conventional single-channel ACFM detection probes, simple oblique cracks can be detected by changing the detection direction, but most other complex-shaped cracks are difficult to detect effectively.

[0004] Therefore, the prior art urgently needs an AC electromagnetic field crack detection probe device that can be used in an underwater environment, which can overcome the problems that the existing detection probe devices cannot be used for underwater detection and that cracks of complex shapes are difficult to detect. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide an underwater array type AC electromagnetic field crack detection probe device to solve the problem that the existing detection probes cannot be used for underwater detection and that cracks of complex shapes are difficult to detect.

[0006] The device includes:

[0007] A housing 1, wherein the housing 1 is filled with insulating oil; the housing 1 has two vertical first ends and a second end;

[0008] A sensor cover 7 is provided at the first end of the shell 1, and a detection module and a mounting seat 6 are built in the sensor cover 7. The detection module includes a data acquisition module and an excitation module; the data acquisition module includes an acquisition chip set 8; the excitation module includes an I-type magnetic core 11 and an excitation coil 10; the I-type magnetic core 11 is placed in the groove of the mounting seat 6, and the excitation coil 10 is wound around the I-type magnetic core 11; the acquisition chip set 8 is provided on a side surface of the lower end surface of the mounting seat 6 and on the end surface facing away from the I-type magnetic core 11; the mounting seat 6 is provided with a wire hole 9; and a connector 13 is provided at the second end of the shell 1.

[0009] In a preferred embodiment, the acquisition chip group 8 includes two groups of acquisition chips, each group of acquisition chips includes four acquisition chips, a total of eight acquisition chips, and the two groups of acquisition chips are vertically mounted on the mounting base 6.

[0010] In a preferred embodiment, the sensor cover 7 is made of zirconium oxide ceramics.

[0011] In a preferred embodiment, the sensor cover 7 is arranged on the first end of the housing 1 through a sealing ring 5 and screws 4 .

[0012] In a preferred embodiment, the sensor cover 7 is sealed with the housing 1 via a sealing ring 12 .

[0013] In a preferred embodiment, the housing is provided with an oil filling hole and is sealed by a screw plug 2 and an O-ring 3 .

[0014] In a preferred embodiment, the sensor cover 7 is a convex-shaped shell.

[0015] In a preferred embodiment, the connector 13 is fixed to the second end of the housing 1 .

[0016] In a preferred embodiment, the connector 13 is threadedly connected to the second end of the housing 1 .

[0017] In a preferred embodiment, the connector 13 is a deep water LEMO connector.

[0018] In a preferred embodiment, the I-type magnetic core 11 is an I-type magnetic core made of manganese-zinc ferrite material.

[0019] In a preferred embodiment, the excitation coil 10 is a double-layer coil.

[0020] The embodiment of the present invention further provides an underwater array AC electromagnetic field crack detection system to solve the problem that the existing detection probe cannot be used for underwater detection and that cracks of complex shapes are difficult to detect. The system comprises:

[0021] The above-mentioned underwater array type AC electromagnetic field crack detection probe device is used to generate an AC electromagnetic field; obtain the magnetic field signal generated by the metal to be tested underwater in the AC electromagnetic field; convert the magnetic field signal into a voltage signal; and output the voltage signal;

[0022] The underwater array type AC electromagnetic field crack detection system circuit is used to receive the voltage signal transmitted by the underwater array type AC electromagnetic field crack detection probe device; perform analog-to-digital conversion and signal amplification processing on the voltage signal; and output the voltage signal after analog-to-digital conversion and signal amplification processing.

[0023] It can be seen from the technical solution provided by an embodiment of an underwater array type AC electromagnetic field crack detection probe device that the embodiment of the present invention is provided with a shell, a sensor cover, a detection module and a connector. First, an AC electromagnetic field is generated by an excitation module in a detection module inside a sensor cover in the shell, and a data acquisition module in the detection module obtains a magnetic field signal generated by the metal to be tested in the AC electromagnetic field, and converts the magnetic field signal into a voltage signal; the voltage signal is output through a connector, so that the crack information can be detected by performing data processing on the voltage signal; compared with the prior art, the problem that the existing detection probe cannot be detected underwater and complex-shaped cracks are difficult to detect is overcome. By setting a detection module, a single effective scanning width can reach 50mm, which improves work efficiency, and can detect complex-shaped crack defects; taking advantage of the characteristics of insulating oil being non-conductive and low in compressibility, the shell of the underwater array type AC electromagnetic field crack detection probe device is filled with insulating oil, which can ensure that the probe works normally in a water depth of 200 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 It is a cross-sectional view of an underwater array type AC electromagnetic field crack detection probe device according to an embodiment of the present invention;

[0026] Figure 2 It is a three-dimensional cross-sectional diagram of an underwater array type AC electromagnetic field crack detection probe device according to an embodiment of the present invention;

[0027] Figure 3 It is a structural schematic diagram of an underwater array type AC electromagnetic field crack detection system according to an embodiment of the present invention;

[0028] Figure 4 It is a specific example diagram of an underwater array-type AC electromagnetic field crack detection system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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 creative work should fall within the scope of protection of the present invention.

[0030] The specific implementation of the embodiments of the present invention is described in detail below with several specific examples. However, it should be noted that the specific embodiments are only for better illustrating the present invention and do not constitute an improper limitation to the present invention.

[0031] The following first introduces an embodiment of an underwater array type AC electromagnetic field crack detection probe device according to an embodiment of the present invention. Figure 1 , Figure 1 : is a cross-sectional view of an underwater array type AC electromagnetic field crack detection probe device according to an embodiment of the present invention. The underwater array type AC electromagnetic field crack detection probe device may include:

[0032] Shell 1, screw plug 2, O-ring 3, screw 4, sealing pressure ring 5, mounting seat 6, sensor cover 7, acquisition chip set 8, wire hole 9, excitation coil 10, I-type magnetic core 11, sealing ring 12, connector 13. The functions of each component in the device and the connection relationship between them are described in detail below to better understand the embodiments of the present invention:

[0033] Reference Figure 1 It can be seen that the shell 1 is filled with insulating oil; the shell 1 has two vertical first and second ends; the first end of the shell 1 is provided with a sensor cover 7, and the sensor cover 7 has a detection module and a mounting seat 6 built in, the detection module includes a data acquisition module and an excitation module; the data acquisition module includes an acquisition chip set 8; the excitation module includes an I-type magnetic core 11 and an excitation coil 10; the I-type magnetic core 11 is placed in the groove of the mounting seat 6, and the excitation coil 10 is wound around the I-type magnetic core 11; the acquisition chip set 8 is arranged on a side surface of the lower end face of the mounting seat 6 and the end face facing away from the I-type magnetic core 11; the mounting seat 6 is provided with a wire hole 9; the sensor cover 7 is arranged on the first end of the shell 1 through a sealing pressure ring 5 and a screw 4; the sensor cover 7 is sealed with the shell 1 through a sealing ring 12; the shell is provided with an oil filling hole, and is sealed by a screw plug 2 and an O-ring 3; the second end of the shell 1 is provided with a connector 13.

[0034] The embodiment of the present invention is provided with a shell, a sensor cover, a detection module and a connector. First, an AC electromagnetic field is generated by an excitation module in the detection module inside the sensor cover in the shell, and a data acquisition module in the detection module obtains the magnetic field signal generated by the metal to be tested in the AC electromagnetic field, and converts the magnetic field signal into a voltage signal; the voltage signal is output through a connector, so that the crack information can be detected by data processing the voltage signal; compared with the prior art, the problem that the existing detection probe cannot be detected underwater and the complex-shaped cracks are difficult to detect is overcome. By setting up a detection module, the single effective scanning width can reach 50mm, which improves the work efficiency and can detect complex-shaped crack defects; taking advantage of the characteristics of insulating oil being non-conductive and low in compressibility, the shell of the underwater array-type AC electromagnetic field crack detection probe device is filled with insulating oil, which can ensure that the probe works normally in a water depth of 200 meters.

[0035] In the prior art, the difficulties faced by ACFM in underwater detection include: water is conductive, which may cause a short circuit in the circuit of the AC electromagnetic field detection probe device.

[0036] In order to solve the above problems, the underwater array type AC electromagnetic field crack detection probe device provided in the embodiment of the present invention is filled with insulating oil in the shell 1. Taking advantage of the characteristics of insulating oil that is non-conductive and has low compressibility, the shell of the underwater array type AC electromagnetic field detection probe is filled with insulating oil, which can ensure that the probe can work normally in a water depth of 200 meters.

[0037] In a preferred embodiment, the acquisition chip group 8 includes two groups of acquisition chips, each group of acquisition chips includes four acquisition chips, a total of eight acquisition chips, and the two groups of acquisition chips are vertically mounted on the mounting base 6.

[0038] In a preferred embodiment, the acquisition chip may be a TMR (Tunnel Magneto Resistance) sensor.

[0039] In the above embodiment, the underwater array type AC electromagnetic field crack detection probe device provided by the embodiment of the present invention has the following advantages: 1. High reliability. By using the above acquisition chip group to form an array type sensor group, the crack to be detected can be scanned and the signal can be picked up, and redundant information and complementary information of the crack object can be provided, which is superior to a single sensor in terms of the detection probability and false alarm probability judgment standards;

[0040] ②Easier operation and faster scanning speed. The above-mentioned acquisition chipset can form an array sensor group, and one scan can detect an area to be detected. In this way, the probe can be simply positioned around the defect, avoiding tracking and scanning the defect, thereby simplifying the operation; multiple sensors work simultaneously to achieve fast measurement;

[0041] ③ Richer defect information. Comprehensive analysis of multiple measurement signals can describe defects at more levels, which is particularly important in the detection of complex welding defects;

[0042] ④ The detection method is more scientific and simple. The array sensor performs surface detection, reducing the reliance on prior judgment of defect direction when measuring with a single sensor.

[0043] In the above embodiment, the detection module adopts an array arrangement of two groups of acquisition chips placed vertically, so that the single effective scanning width can reach 50mm, thereby improving work efficiency. At the same time, it can also detect complex-shaped crack defects, solving the problem that existing detection probes are difficult to detect complex-shaped cracks.

[0044] In the prior art, the difficulties faced by ACFM in underwater detection also include: 1. The generation of distorted magnetic field signals is excited by electromagnetic induction by the excitation circuit in the detection module of the detection probe, and the presence of the metal shell of the detection probe will produce an electromagnetic shielding effect. 2. Due to the influence of the lift-off effect during the electromagnetic induction process, the thickness of the probe cover that isolates the water and the detection module is greatly limited. If the probe cover is thick, it will seriously affect the detection effect of metal cracks, and the strength of thin shell non-metallic materials is difficult to resist deep water pressure alone.

[0045] The underwater array type AC electromagnetic field crack detection probe device provided by the embodiment of the present invention can be used to solve the above problems. In a preferred embodiment, a sensor cover 7 can be arranged between the detection module and the workpiece, and the sensor cover 7 can be made of non-metallic material zirconium oxide ceramics.

[0046] In the above embodiment, the sensor cover 7 may be a zirconia ceramic shell. Zirconia ceramic is a material with high strength, high hardness and good wear resistance. In the embodiment of the present invention, the shell 7 adopts a zirconia ceramic shell to extend the service life of the shell, and also avoids the problem of electromagnetic shielding caused by the metal shell of the detection probe in the prior art. Of course, in actual use, shells of other materials can also be selected as long as the performance of the shell is guaranteed. However, since the AC electromagnetic field detection can be affected by the electromagnetic lift-off effect and electromagnetic induction, in order to ensure the detection effect, the thickness of the part of the sensor cover that is in direct contact with the surface of the metal structure to be tested is set to 1mm, thereby avoiding the problem of the thick probe cover affecting the detection effect of metal cracks.

[0047] In a preferred embodiment, in order to facilitate disassembly, the sensor cover 7 and the housing 1 may be detachably connected. Figure 1 The underwater array type AC electromagnetic field crack detection probe device may include a screw 4 and a sealing pressure ring 5.

[0048] In the embodiment, by using sealing measures such as a sealing pressure ring and a sealing ring, the probe can be guaranteed to work normally in a water depth of 200 meters. Accordingly, the sensor cover 7 can be set at the first end of the housing 1 by means of a screw 4 and a sealing pressure ring 5. Specifically, the screw 4 can be a semi-countersunk cross-slot screw. Of course, in actual use, other ways can also be selected to connect the sensor cover 7 and the housing 1, as long as they can be detachable.

[0049] In practical applications, the shell 1 in the embodiment of the present invention may be a detection probe housing in an underwater array type AC electromagnetic field crack detection probe device, and the shell 1 may be a handle in an underwater array type AC electromagnetic field crack detection probe device.

[0050] In a preferred embodiment, in order to achieve sealing of the sensor cover 7 , the sensor cover 7 can be sealed with the housing 1 via a sealing ring 12 .

[0051] In a preferred embodiment, in order to realize the operation of injecting insulating oil into the sensor cover 7 , the housing is provided with an oil filling hole, which can be sealed by a screw plug 2 and an O-ring 3 .

[0052] In a preferred embodiment, in order to reduce the volume of the underwater array AC electromagnetic field crack detection probe device, the shell 1 can be set to a convex shell to form a shape that is compatible with the built-in acquisition chipset 8, chip seat 6, I-type magnetic core 11 and excitation coil 10.

[0053] In the above embodiment, the detection chip group 8 is arranged on a side surface of the lower end surface of the mounting seat 6 and the end surface facing away from the I-type magnetic core 11; the mounting seat 6 is provided with a wire hole 9, and by providing the wire hole 9, the sensor chips can be compactly installed side by side in a small space, and the sensor wire core passes through the wire hole 9, thereby solving the problem of inconvenience in wiring caused by a large number of wire cores.

[0054] In a preferred embodiment, the connector 13 can be fixed to the second end of the housing 1, and the connection between the connector 13 and the second end of the housing 1 is a threaded connection.

[0055] In the above embodiment, the connector 13 may be a LEMO connector. Furthermore, the connector of the LEMO connector may be EVG.3W.326.CLL. By setting the connector, the voltage signal generated by the detection module can be transmitted, and then the crack information can be detected by performing data processing on the voltage signal. Of course, in actual use, other connectors can also be selected as long as the detected voltage signal can communicate with the data processing module on the signal acquisition board.

[0056] The connector 13 may include a waterproof connector.

[0057] In a preferred embodiment, the I-type magnetic core 11 may be an I-type magnetic core made of manganese-zinc ferrite material. By providing the I-type magnetic core 11, a uniform and strong induced current can be efficiently excited on the surface of the workpiece.

[0058] In a preferred embodiment, in order to ensure the signal when cracks are detected, the excitation coil 10 may be a double-layer coil.

[0059] For example, Figure 2 This is a three-dimensional cross-sectional diagram of an underwater array type AC electromagnetic field crack detection probe device according to an embodiment of the present invention. Figure 1 To understand the various structures in the figure, the three-dimensional cross-sectional diagram of the underwater array AC electromagnetic field crack detection probe device shows the following structure:

[0060] Shell 1, screw plug 2, O-ring 3, screw 4, sealing pressure ring 5, mounting seat 6, sensor cover 7, detection chip set 8, wire hole 9, excitation coil 10, I-type magnetic core 11, sealing ring 12, connector 13.

[0061] The embodiment of the present invention is provided with a shell, a sensor cover, a detection module and a connector. First, an AC electromagnetic field is generated by an excitation module in the detection module inside the sensor cover in the shell, and a data acquisition module in the detection module obtains the magnetic field signal generated by the metal to be tested in the AC electromagnetic field, and converts the magnetic field signal into a voltage signal; the voltage signal is output through a connector, so that the crack information can be detected by data processing the voltage signal; compared with the prior art, the problem that the existing detection probe cannot be detected underwater and the complex-shaped cracks are difficult to detect is overcome. By setting up a detection module, the single effective scanning width can reach 50mm, which improves the work efficiency and can detect complex-shaped crack defects; taking advantage of the characteristics of insulating oil being non-conductive and low in compressibility, the shell of the underwater array AC electromagnetic field crack detection probe device is filled with insulating oil, which can ensure the normal operation of the probe in a water depth of 200 meters.

[0062] As described above, the embodiments of the present invention can realize crack detection of metal structures with coatings on the surface in deep water environment, and the effective width of each detection can reach 50mm, and it can realize the detection of complex cracks. Under laboratory conditions, using the underwater array AC electromagnetic field crack detection probe device provided by the embodiment of the present invention to scan the artificial complex crack defect test plate, the minimum crack defect length can be detected to be 8mm.

[0063] The embodiment of the present invention further provides an underwater array type AC electromagnetic field crack detection method, the method comprising the following steps:

[0064] 1. Generate an AC electromagnetic field through an excitation module in a detection module inside a sensor cover in a housing;

[0065] 2. The data acquisition module in the detection module obtains the magnetic field signal generated by the metal to be tested in the AC electromagnetic field, and converts the magnetic field signal into a voltage signal;

[0066] 3. Output the voltage signal through a connector.

[0067] The embodiment of the present invention can ultimately detect crack information by performing data processing on the voltage signal.

[0068] The embodiment of the present invention generates an AC electromagnetic field through an excitation module in a detection module inside a sensor cover in a shell, and a data acquisition module in the detection module obtains a magnetic field signal generated by the metal to be tested in the AC electromagnetic field, and converts the magnetic field signal into a voltage signal; the voltage signal is output through a connector, so that crack information can be detected by performing data processing on the voltage signal; compared with the prior art, the problem that the existing detection probe cannot perform underwater detection and that complex-shaped cracks are difficult to detect is overcome, and by setting a detection module, a single effective scanning width can reach 50 mm, thereby improving work efficiency, and at the same time, complex-shaped crack defects can be detected; utilizing the characteristics of insulating oil being non-conductive and having low compressibility, the shell of the underwater array-type AC electromagnetic field crack detection probe device is filled with insulating oil, which can ensure that the probe works normally in a water depth of 200 meters.

[0069] The embodiment of the present invention also provides an underwater array type AC electromagnetic field crack detection system, such as Figure 3 As shown, the system may include:

[0070] The above-mentioned underwater array type AC electromagnetic field crack detection probe device 01 is used to generate an AC electromagnetic field; obtain the magnetic field signal generated by the metal to be tested underwater in the AC electromagnetic field; convert the magnetic field signal into a voltage signal; and output the voltage signal;

[0071] The underwater array AC electromagnetic field crack detection system circuit 02 is used to receive the voltage signal transmitted by the underwater array AC electromagnetic field crack detection probe device; perform analog-to-digital conversion and signal amplification processing on the voltage signal; and output the voltage signal after analog-to-digital conversion and signal amplification processing.

[0072] When implementing it, Figure 4 As shown, the underwater array AC electromagnetic field crack detection system circuit provided by the embodiment of the present invention may include: a sinusoidal excitation signal circuit, a power amplifier circuit, a multi-op-amp signal conditioning circuit and a NI acquisition card data processing circuit;

[0073] The sinusoidal excitation signal circuit is used to provide a high-frequency sinusoidal excitation signal; the high-frequency sinusoidal excitation signal is transmitted to the power amplifier circuit;

[0074] The power amplifier circuit is used to drive the excitation module according to the high-frequency sinusoidal excitation signal; and transmit the high-frequency sinusoidal excitation signal to the acquisition module through the excitation module;

[0075] The acquisition module is used to convert the weak magnetic field disturbance caused by the existence of crack defects into a voltage signal according to the high-frequency sinusoidal excitation signal; the voltage signal is transmitted to the NI acquisition card data processing circuit through the multi-op-amp signal conditioning circuit;

[0076] The NI acquisition card data processing circuit is used to complete A / D conversion (analog-to-digital conversion) of the voltage signal; complete digital filtering, image smoothing and data storage of the acquired data.

[0077] In one embodiment, the sinusoidal excitation signal circuit is specifically used for: in AC electromagnetic field nondestructive testing, the frequency, amplitude and stability of the excitation signal have a significant impact on the detection results; in order to improve the sensitivity of crack detection, COMSOL multi-physics field simulation analysis software can be used as a tool to establish a numerical model of the electromagnetic field distribution in the AC electromagnetic field detection process, perform solution analysis, and finally obtain an optimal excitation frequency scheme. The sinusoidal excitation signal circuit generates an accurate and stable sine wave with an excitation frequency of 6kHz and a Vp-p (peak-to-peak) value of 2V.

[0078] The power amplifier circuit is specifically used for: the output power of the sinusoidal excitation signal circuit is relatively small, which is not enough to drive the array detection probe excitation module. Therefore, the power amplifier circuit can amplify the 6kHz, 2Vp-p sinusoidal signal to a 6kHz, 14.4Vp-p sinusoidal excitation signal for driving the excitation module.

[0079] The multi-op-amp signal conditioning circuit is specifically used for: the magnetic field change signal of the crack part collected by the acquisition chip is weak and has a large amount of dry noise signal, which needs to be amplified and filtered. Since the array probe is arranged with 8 acquisition chips, each acquisition chip needs to amplify the signal, so a multi-op-amp signal conditioning circuit needs to be designed.

[0080] The NI acquisition card data processing circuit is specifically used for: In order to enable the computer to collect the detected weak signals, the analog signal output by the multi-op amp conditioning circuit must be converted into a digital signal that can be accepted by the computer through the NI acquisition card data processing circuit. Finally, the computer software completes the digital filtering, image smoothing and data storage of the collected data.

[0081] 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.

[0082] Although the present invention has been described by way of embodiments, persons skilled in the art will appreciate that there are many modifications and variations of the present invention without departing from the spirit of the present invention. It is intended that the appended claims include these modifications and variations without departing from the spirit of the present invention.

Claims

1. An underwater array AC electromagnetic field crack detection system, characterized in that: include: An underwater array type AC electromagnetic field crack detection probe device is used to generate an AC electromagnetic field; obtain a magnetic field signal generated by the metal to be tested underwater in the AC electromagnetic field; Converting the magnetic field signal into a voltage signal; outputting the voltage signal; The underwater array AC electromagnetic field crack detection system circuit is used to receive the voltage signal transmitted by the underwater array AC electromagnetic field crack detection probe device; perform analog-to-digital conversion and signal amplification processing on the voltage signal; Output voltage signal after analog-to-digital conversion and signal amplification; The underwater array AC electromagnetic field crack detection system circuit includes: a sinusoidal excitation signal circuit, a power amplifier circuit, a multi-op-amp signal conditioning circuit and a NI acquisition card data processing circuit; The sinusoidal excitation signal circuit is used to provide a high-frequency sinusoidal excitation signal; the high-frequency sinusoidal excitation signal is transmitted to the power amplifier circuit; The power amplifier circuit is used to drive the excitation module according to the high-frequency sinusoidal excitation signal; and transmit the high-frequency sinusoidal excitation signal to the acquisition module through the excitation module; The acquisition module is used to convert the weak magnetic field disturbance caused by the existence of crack defects into a voltage signal according to the high-frequency sinusoidal excitation signal; the voltage signal is transmitted to the NI acquisition card data processing circuit through the multi-op-amp signal conditioning circuit; The NI acquisition card data processing circuit is used to complete analog-to-digital conversion of voltage signals; complete digital filtering, image smoothing and data storage of the acquired data; The sinusoidal excitation signal circuit is specifically used for: using COMSOL multi-physics field simulation analysis software as a tool, establishing a numerical model of electromagnetic field distribution in the process of AC electromagnetic field detection, performing solution analysis, and obtaining an optimal scheme for excitation frequency; the sinusoidal excitation signal circuit generates an accurate and stable sinusoidal wave with an excitation frequency of 6kHz and a peak-to-peak value of 2V; The power amplifier circuit is specifically used to: amplify the 6kHz, 2Vp-p sinusoidal signal into a 6kHz, 14.4Vp-p sinusoidal excitation signal for driving the excitation module; The multi-op-amp signal conditioning circuit is specifically used for: amplifying and filtering the magnetic field change signal of the crack part collected by the acquisition chip; The NI acquisition card data processing circuit is specifically used to: convert the analog signal output by the multi-op-amp conditioning circuit into a digital signal that can be accepted by the computer through the NI acquisition card data processing circuit; the computer software completes the digital filtering, image smoothing and data storage processing of the acquired data; The underwater array AC electromagnetic field crack detection probe device includes: A shell (1), wherein the shell (1) is filled with insulating oil; the shell (1) has two perpendicular first and second ends; a sensor cover (7) is provided at the first end of the shell (1), wherein the sensor cover (7) has a detection module and a mounting seat (6) built therein, wherein the detection module comprises a data acquisition module and an excitation module; the data acquisition module comprises an acquisition chipset (8); the excitation module comprises an I-type magnetic core (11) and an excitation coil (10); the I-type magnetic core (11) is placed in a groove of the mounting seat (6), and the excitation coil (10) is wound around the outside of the I-type magnetic core (11); the acquisition chipset (8) is provided on a side surface of the lower end surface of the mounting seat (6) and on an end surface facing away from the I-type magnetic core (11); the mounting seat (6) is provided with a wire through hole (9); the second end of the shell (1) is provided with a connector (13); The acquisition chip group (8) includes two groups of acquisition chips, each group of acquisition chips includes four acquisition chips, a total of eight acquisition chips, and the two groups of acquisition chips are vertically mounted on the mounting base (6); the acquisition chip is a tunnel magnetoresistance sensor; The I-type magnetic core (11) is an I-type magnetic core made of manganese-zinc ferrite material; the excitation coil (10) is a double-layer coil; The sensor cover (7) is made of zirconium oxide ceramic; the sensor cover (7) is arranged on the first end of the shell (1) through a sealing pressure ring (5) and a screw (4); the sensor cover (7) is sealed with the shell (1) through a sealing ring (12); the shell is provided with an oil filling hole and is sealed by a screw plug (2) and an O-ring (3); the sensor cover (7) is a convex shell; the connector (13) is fixed to the second end of the shell (1); the connector (13) and the second end of the shell (1) are threadedly connected; the connector (13) is a deep water Lemo connector.

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