Automatic noise reduction type magnetostrictive guided wave monitoring transducer

Abstract

The utility model discloses an automatic noise reduction type magnetostrictive guided wave monitoring transducer. The sensor shell is placed on a to-be-tested sample, the electromagnetic noise receiving sensor, the excitation sensor, the phase inverter, the summator and the damping spring are all located in the sensor shell, and the electromagnetic noise receiving sensor and the excitation sensor are both fixedly connected to the upper surface of the to-be-tested sample. Damping springs are arranged above the electromagnetic noise receiving sensor and the excitation sensor, the excitation sensor is connected with the adder through a phase inverter, the electromagnetic noise receiving sensor is connected with the adder through a cable, the electromagnetic noise receiving sensor and the excitation sensor are respectively provided with an enameled wire and a backing layer, and the enameled wires are wound on the backing layers. According to the noise reduction type transducer, electromagnetic noise is effectively filtered, guided wave signals are amplified, the accuracy of guided wave monitoring data is improved, the influence of interference signals on monitoring results is avoided, the interference signals can be effectively restrained, and the service life of the transducer is prolonged.

Description

Technical Field

[0001] This utility model belongs to the interdisciplinary field of magnetostrictive sensors and guided wave monitoring, and specifically relates to an automatic noise reduction type magnetostrictive guided wave monitoring transducer. Background Technology

[0002] In long-term guided wave monitoring, magnetostrictive sensors are commonly used to excite and receive guided wave signals. However, in harsh electromagnetic environments, sensors are susceptible to electromagnetic interference, leading to signal contamination and interference. These interference signals may originate from electromagnetic fields, power supplies, cables, or other electronic devices, and their frequencies and amplitudes are similar to guided wave signals, making them difficult to distinguish. Magnetostrictive sensor technology utilizes the magnetostrictive effect to measure physical quantities. The magnetostrictive effect refers to the minute length changes that occur when ferromagnetic materials are magnetized under the influence of a magnetic field. Such materials can be used as sensors to obtain information about the measured physical quantity by measuring the changes in the magnetostrictive sheet. Ultrasonic guided wave nondestructive testing technology, with its advantages of long distance, wide range, and single-end transmission and reception, is widely used in various fields. Ultrasonic guided wave technology possesses numerous advantages: 1. High sensitivity: Guided wave monitoring exhibits high sensitivity, capable of detecting signals in structures far from sensors; 2. Wide bandwidth: Guided wave monitoring can monitor across a wide frequency range, suitable for guided wave signals in different frequency bands; 3. Real-time capability: Guided wave monitoring can record and analyze guided wave signals in real time, promptly detecting structural health conditions and effectively preventing accidents; 4. Non-contact long-distance propagation: Guided wave monitoring technology is a non-destructive testing method. Guided waves can propagate over long distances and over a wide area, avoiding destructive testing and the possibility of personnel injury. This single-end transmission and reception characteristic, enabling long-distance propagation, provides unique advantages for detecting and monitoring objects with cladding layers or those difficult to access. Guided wave technology is widely used in structural health monitoring, such as in bridges, buildings, and aircraft. By monitoring and analyzing the propagation characteristics and changes of guided wave signals, the health condition, damage, or defects of structures can be detected and assessed, thereby preventing accidents.

[0003] Traditional magnetostrictive sensors often employ filters to remove interference signals when encountering electromagnetic noise. However, traditional filters have several drawbacks: 1. Signal distortion: Filters frequently introduce phase delay and amplitude distortion, leading to errors in monitoring results; 2. Inability to adapt quickly: Traditional methods require manual adjustment of filter parameters, making it difficult to adapt quickly to different electromagnetic interference environments, reducing real-time performance and applicability; 3. Increased energy consumption: Traditional filters consume additional energy to process interference signals, increasing the sensor's energy consumption and maintenance costs. Therefore, a new technology is urgently needed to address the problem of electromagnetic noise pollution and interference in long-term guided wave monitoring of traditional magnetostrictive sensors. This new technology will automatically filter out electromagnetic noise, improving the accuracy and reliability of monitoring results. Utility Model Content

[0004] In order to solve the problems existing in the background technology, the purpose of this utility model is to provide an automatic noise reduction type magnetostrictive guided wave monitoring transducer.

[0005] The technical solution adopted in this utility model is as follows:

[0006] The guided wave monitoring transducer includes an electromagnetic noise receiving sensor, a sensor housing, an excitation sensor, an inverter, an adder, and a damping spring. The sensor housing is placed on the sample to be tested. The electromagnetic noise receiving sensor, the excitation sensor, the inverter, the adder, and the damping spring are all located inside the sensor housing. The electromagnetic noise receiving sensor and the excitation sensor are both fixedly connected to the upper surface of the sample to be tested, and a damping spring is placed above both the electromagnetic noise receiving sensor and the excitation sensor. The excitation sensor is connected to the adder through the inverter, and the electromagnetic noise receiving sensor is connected to the adder through a cable.

[0007] The electromagnetic noise receiving sensor includes an electromagnetic enameled wire, an electromagnetic backing layer, and a padding layer. The electromagnetic enameled wire is wound around the outer periphery of the electromagnetic backing layer, and the electromagnetic backing layer with the electromagnetic enameled wire wound on it is placed on the padding layer. The padding layer is bonded to the sample under test by a waveguide coupling agent. The excitation sensor includes an excitation enameled wire, an excitation backing layer, and a magnetostrictive tape. The excitation enameled wire is wound around the outer periphery of the excitation backing layer, and the excitation backing layer with the excitation enameled wire wound on it is placed on the magnetostrictive tape. The magnetostrictive tape is bonded to the sample under test by a waveguide coupling agent. The electromagnetic noise receiving sensor and the excitation sensor are arranged at intervals.

[0008] The adder includes an operational amplifier, a first input resistor R1, a second input resistor R2, a balancing resistor R3, and a feedback resistor R. f One end of the first input resistor R1 is led out as the first input port of the adder, and one end of the second input resistor R2 is led out as the second input port of the adder. The other ends of the first input resistor R1 and the second input resistor R2 are connected in parallel. The circuit after the first input resistor R1 and the second input resistor R2 are connected to the feedback resistor R. f One end is connected to one input port of the operational amplifier, and the feedback resistor R f The other end of the resistor is connected to the output port of the operational amplifier and serves as the output port of the adder. One end of the balancing resistor R3 is connected to the other input port of the operational amplifier, and the other end of the balancing resistor R3 is grounded.

[0009] Among them, the second input resistor R2 and the feedback resistor R fThe resistance values ​​are all fixed. The first input resistor R1 and the balancing resistor R3 are sliding rheostats, and their resistance values ​​can be adjusted as needed. The resistance value of the balancing resistor R3 is equal to the first input resistor R1, the second input resistor R2, and the feedback resistor R... f And, that is

[0010] R3=1 / ((1 / R1)+(1 / R2)+(1 / R f ))

[0011] Where R1 represents the resistance value of the first input resistor, R2 represents the resistance value of the second input resistor, and R... f R1 represents the resistance value of the feedback resistor, and R2 represents the resistance value of the balancing resistor.

[0012] The transducer is equipped with two sets of damping springs. One set of damping springs is placed on the electromagnetic backing layer of the electromagnetic noise receiving sensor, and the other set of damping springs is placed on the excitation backing layer of the excitation sensor. The sensor housing is placed on the damping springs.

[0013] The excitation sensor is connected to one end of the inverter, the other end of the inverter is connected to the first input port of the adder, the electromagnetic noise receiving sensor is connected to the second input port of the adder, and the output port of the adder is connected to an external waveguide detection device via a cable.

[0014] The resistance value of the balancing resistor R3 is obtained by the following method:

[0015] R3=1 / ((1 / R1)+(1 / R2)+(1 / R f ))

[0016] Where R1 represents the resistance value of the first input resistor, R2 represents the resistance value of the second input resistor, and R... f R1 represents the resistance value of the feedback resistor, and R2 represents the resistance value of the balancing resistor.

[0017] The electromagnetic backing layer and the excitation backing layer are made of non-ferromagnetic materials with a thickness of 0.8 mm to 1.2 mm.

[0018] The magnetostrictive tape is made of iron-cobalt-nickel alloy material with a thickness of 1mm to 2mm, and the pad is made of aluminum alloy material. The thickness of the pad is the same as that of the magnetostrictive tape.

[0019] The operational amplifier is an integrated operational amplifier.

[0020] The adder uses an inverting addition circuit.

[0021] Preferably, the inverter is a CMOS inverter composed of two enhancement-mode MOSFETs.

[0022] Preferably, the operational amplifier is an integrated operational amplifier.

[0023] Preferably, the excitation sensor and the electromagnetic noise receiving sensor are respectively closely attached to the sample under test through a waveguide coupling agent, thereby improving the waveguide acoustic energy conversion efficiency.

[0024] Preferably, the waveguide coupling agent is an epoxy coupling agent.

[0025] Preferably, the adder is an inverting adder circuit.

[0026] This invention utilizes a cleverly designed excitation sensor and electromagnetic noise receiving sensor, coupled with corresponding inverters and adders, to effectively filter electromagnetic noise and amplify the guided wave signal. This improves the accuracy of guided wave monitoring data, avoids the influence of interference signals on the monitoring results, and makes the monitoring results more reliable. Furthermore, traditional guided wave transducers are easily damaged by interference signals in poor electromagnetic environments, which can shorten their lifespan. This noise-reducing transducer effectively suppresses interference signals and extends the sensor's lifespan.

[0027] The beneficial effects of this utility model are:

[0028] 1. This utility model uses an inverter to invert the phase of the electromagnetic noise signal without changing the signal amplitude. This can better remove electromagnetic noise without affecting the guided wave signal itself, thereby improving the signal-to-noise ratio and stability of the guided wave signal.

[0029] 2. This utility model can not only eliminate electromagnetic noise, but also amplify the guided wave signal by using an inverting addition circuit. This noise-reducing transducer can effectively suppress interference signals and extend the service life of the sensor. Attached Figure Description

[0030] Figure 1 This is a block diagram of the connection structure between the magnetostrictive guided wave monitoring transducer and the guided wave detection equipment of this utility model.

[0031] Figure 2 This is a block diagram of the automatic noise reduction magnetostrictive guided wave monitoring transducer and the sample to be tested according to this utility model.

[0032] Figure 3 This is a schematic diagram of the enameled wire wound around the backing layer of the magnetostrictive guided wave monitoring transducer of this utility model.

[0033] Figure 4 This is the circuit diagram of the adder of the automatic noise reduction magnetostrictive guided wave monitoring transducer of this utility model.

[0034] Figure 5This is a waveform diagram before noise reduction obtained from an embodiment of the magnetostrictive guided wave monitoring transducer of this utility model.

[0035] Figure 6 This is a waveform diagram after noise reduction obtained from an embodiment of the magnetostrictive guided wave monitoring transducer of this utility model.

[0036] Figure 7 This is a waveform diagram showing the waveforms before and after noise reduction obtained from an embodiment of the transducer of this utility model.

[0037] In the figure: 1-Sample to be tested; 2-Insulation layer; 3-Electromagnetic noise receiving sensor; 4-Sensor housing; 5-Excitation sensor; 6-Magnetostrictive strip; 7-Inverter; 8-Adder; 9-Waveguide testing equipment; 10-Cable; 11-Backing layer; 12-Enameled wire; 13-Damping spring; 14-Operative amplifier; 15-Ground. Detailed Implementation

[0038] The present invention will be described in detail below with reference to specific implementation examples. The following implementation examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way.

[0039] like Figure 1 and Figure 2 As shown, the transducer includes an electromagnetic noise receiving sensor 3, a sensor housing 4, an excitation sensor 5, an inverter 7, an adder 8, and a damping spring 13. The sensor housing 4 is placed on the sample 1 to be tested. The electromagnetic noise receiving sensor 3, the excitation sensor 5, the inverter 7, the adder 8, and the damping spring 13 are all located inside the sensor housing 4. The electromagnetic noise receiving sensor 3 and the excitation sensor 5 are both fixedly connected to the upper surface of the sample 1 to be tested, and a damping spring 13 is placed above both the electromagnetic noise receiving sensor 3 and the excitation sensor 5. The excitation sensor 5 is connected to the adder 8 through the inverter 7, and the electromagnetic noise receiving sensor 3 is connected to the adder 8 through a cable.

[0040] like Figure 3 As shown, the electromagnetic noise receiving sensor 3 includes an electromagnetic enameled wire, an electromagnetic backing layer, and a pad 2. The electromagnetic enameled wire is wound around the outer periphery of the electromagnetic backing layer, and the electromagnetic backing layer with the electromagnetic enameled wire wound on it is placed on the pad 2. The pad 2 is bonded to the sample 1 under test by a waveguide coupling agent. The excitation sensor 5 includes an excitation enameled wire, an excitation backing layer, and a magnetostrictive tape 6. The excitation enameled wire is wound around the outer periphery of the excitation backing layer, and the excitation backing layer with the excitation enameled wire wound on it is placed on the magnetostrictive tape 6. The magnetostrictive tape 6 is bonded to the sample 1 under test by a waveguide coupling agent. The electromagnetic noise receiving sensor 3 and the excitation sensor 5 are arranged side by side with a gap between them, and there is no contact between them.

[0041] Both the electromagnetic enameled wire and the excitation enameled wire are enameled wire 12, and the electromagnetic enameled wire and the excitation enameled wire are made of the same material. Both the electromagnetic backing layer and the excitation backing layer are backing layer 11, and the electromagnetic backing layer and the excitation backing layer are made of the same material. The electromagnetic noise receiving sensor 3 and the excitation sensor 5 are placed side by side and close to each other.

[0042] like Figure 4 As shown, the adder 8 includes an operational amplifier 14, a first input resistor R1, a second input resistor R2, a balancing resistor R3, and a feedback resistor R. f One end of the first input resistor R1 is led out as the first input port of the adder 8, and one end of the second input resistor R2 is led out as the second input port of the adder 8. The other ends of the first input resistor R1 and the second input resistor R2 are connected in parallel, that is, the other ends of the first input resistor R1 and the other ends of the second input resistor R2 are connected together. The circuit after the first input resistor R1 and the second input resistor R2 are connected to the feedback resistor R through the cable 10. f One end is connected to one input port of operational amplifier 14, and the feedback resistor R f The other end is connected to the output port of operational amplifier 14 and serves as the output port of adder 8. One end of balancing resistor R3 is connected to another input port of operational amplifier 14 via cable 10, and the other end of balancing resistor R3 is connected to ground 15.

[0043] Among them, the second input resistor R2 and the feedback resistor R f The resistance values ​​are all fixed. The first input resistor R1 and the balancing resistor R3 are sliding rheostats, and their resistance values ​​can be adjusted as needed. The resistance value of the balancing resistor R3 is equal to the first input resistor R1, the second input resistor R2, and the feedback resistor R... f And, that is

[0044] R3=1 / ((1 / R1)+(1 / R2)+(1 / R f ))

[0045] Where R1 represents the resistance value of the first input resistor, R2 represents the resistance value of the second input resistor, and R... f R1 represents the resistance value of the feedback resistor, and R2 represents the resistance value of the balancing resistor.

[0046] Specifically, the positive input terminal of operational amplifier 14 is connected to the first input resistor R1, the second input resistor R2, and the feedback resistor R1, respectively. f The negative input terminal of operational amplifier 14 is connected to the balancing resistor R3.

[0047] The transducer is equipped with two sets of damping springs 13. One set of damping springs 13 is placed on the electromagnetic backing layer of the electromagnetic noise receiving sensor 3, and the other set of damping springs 13 is placed on the excitation backing layer of the excitation sensor 5. The sensor housing 4 is placed on the damping springs 13 to fix the waveguide transducer of this utility model.

[0048] In the specific implementation, there are a total of 12 damping springs 13. One group of 6 springs is evenly placed on the electromagnetic noise receiving sensor 3, and the other group of 6 springs is evenly placed on the excitation sensor 5.

[0049] Excitation sensor 5 is connected to one end of inverter 7, and the other end of inverter 7 is connected to the first input port of adder 8. Electromagnetic noise receiving sensor 3 is connected to the second input port of adder 8. The output port of adder 8 is connected to waveguide detection device 9 via cable 10.

[0050] Specifically, inverter 7 is electrically connected to the first input resistor R1, electromagnetic noise receiving sensor 3 is electrically connected to the second input resistor R2, and feedback resistor R... f Both operational amplifier 14 and waveguide detection device 9 are connected.

[0051] The resistance value of the balancing resistor R3 is obtained by processing it as follows:

[0052] R3=1 / ((1 / R1)+(1 / R2)+(1 / R f ))

[0053] Where R1 represents the resistance value of the first input resistor, R2 represents the resistance value of the second input resistor, and R... f R1 represents the resistance value of the feedback resistor, and R2 represents the resistance value of the balancing resistor.

[0054] The electromagnetic backing layer and the excitation backing layer are made of non-ferromagnetic materials with a thickness of 0.8 mm to 1.2 mm.

[0055] The magnetostrictive tape 6 is made of iron-cobalt-nickel alloy material with a thickness of 1mm to 2mm. This material has a flexible sheet structure. The pad 2 is made of aluminum alloy material, and the thickness of the pad 2 is the same as that of the magnetostrictive tape 6.

[0056] Operational amplifier 14 is an integrated operational amplifier. The adder uses an inverting adder circuit.

[0057] Let the output signals of the excitation sensor and the electromagnetic noise receiving sensor be Ps and Pn, respectively, where Ps = S1 + noise and Pn = noise, where S1 is the guided wave signal and noise is the electromagnetic noise signal; Figure 1 As shown, the signal obtained after passing through inverter 7 is set as Pf = -Ps = -(S1 + noise).

[0058] Furthermore, by Figure 4 We know that the output signal of adder 8 is set as Pj, and the expression of the output signal Pj is as follows:

[0059] Pj=-((R f / R1)×Pf+(R f / R2)×Pn)=-((R f / R1)×(-(S1+noise))+(R f / R2)×noise)

[0060] As can be seen, by adjusting the sliding rheostat R1 so that the input resistance R1 equals the input resistance R2, assuming R1 = R2 = R, the above equation can be simplified to:

[0061] Pj=-((R f / R1)×(-(S1+noise))+(R f / R2)×noise)=(R f / R)×S1

[0062] It can be seen that the electromagnetic noise signal is eliminated while the guided wave signal S1 is preserved, and the amplification of R is achieved. f / R times.

[0063] Therefore, as a beneficial effect, this invention can not only eliminate electromagnetic noise, but also amplify guided wave signals by different factors.

[0064] In this embodiment, a turnout switch rail, approximately 22 meters long, is used as the object under test. The guided wave operation mode is single-transmitter, single-receiver mode, and the transducer proposed in this invention serves as the receiving sensor in the single-transmitter, single-receiver guided wave mode. First, according to... Figure 1 Connect the detection equipment as shown; secondly, without providing a guided wave excitation signal, adjust the sliding rheostat (i.e., input resistor R1) to make the output of adder 8 zero. Then, adjust the sliding rheostat-balancing resistor R3 so that the resistance of the balancing resistor R3 is equal to the first input resistor R1, the second input resistor R2, and the feedback resistor R... f And, that is

[0065] R3=1 / ((1 / R1)+(1 / R2)+(1 / R f ))

[0066] Where R1 represents the resistance value of the first input resistor, R2 represents the resistance value of the second input resistor, and R... f R1 represents the resistance value of the feedback resistor, and R2 represents the resistance value of the balancing resistor.

[0067] Secondly, in single-transmitter, single-receiver mode, a guided wave excitation signal is applied, and the received guided wave signal is as follows: Figure 6 The red waveform in the diagram (i.e., the noise-reduced signal); next, inverter 7 is removed, meaning no inversion is performed, so the electromagnetic noise signals received by the excitation sensor and the electromagnetic noise receiving sensor are in phase, and then added by an adder. Since they are in phase, the electromagnetic noise signals will not cancel each other out; next, the guided wave signal is excited, and the received signal is as follows... Figure 5 The blue waveform in the image (i.e., the signal before noise reduction); for comparison, Figure 5 and Figure 6 Display them together, such as Figure 7 As shown in the waveforms before and after noise reduction, it can be seen that the design structure of this invention with noise reduction function can effectively filter out electromagnetic noise in the environment and improve the signal-to-noise ratio of the guided wave signal. In actual long-term guided wave monitoring, it has important engineering application value and significance for ensuring the stability and signal-to-noise ratio of the guided wave signal.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An automatic noise reduction magnetostrictive guided wave monitoring transducer, characterized in that: The device includes an electromagnetic noise receiving sensor (3), a sensor housing (4), an excitation sensor (5), an inverter (7), an adder (8), and a damping spring (13). The sensor housing (4) is placed on the sample to be tested (1). The electromagnetic noise receiving sensor (3), the excitation sensor (5), the inverter (7), the adder (8), and the damping spring (13) are all located inside the sensor housing (4). The electromagnetic noise receiving sensor (3) and the excitation sensor (5) are both fixedly connected to the upper surface of the sample to be tested (1). A damping spring (13) is placed above both the electromagnetic noise receiving sensor (3) and the excitation sensor (5). The excitation sensor (5) is connected to the adder (8) through the inverter (7). The electromagnetic noise receiving sensor (3) is connected to the adder (8) through a cable.

2. The automatic noise reduction magnetostrictive guided wave monitoring transducer according to claim 1, characterized in that: The electromagnetic noise receiving sensor (3) includes an electromagnetic enameled wire, an electromagnetic backing layer, and a pad (2). The electromagnetic enameled wire is wound around the outer periphery of the electromagnetic backing layer. The electromagnetic backing layer with the electromagnetic enameled wire is placed on the pad (2). The pad (2) is bonded to the sample (1) to be tested. The excitation sensor (5) includes an excitation enameled wire, an excitation backing layer, and a magnetostrictive tape (6). The excitation enameled wire is wound around the outer periphery of the excitation backing layer. The excitation backing layer with the excitation enameled wire is placed on the magnetostrictive tape (6). The magnetostrictive tape (6) is bonded to the sample (1) to be tested. The electromagnetic noise receiving sensor (3) and the excitation sensor (5) are arranged at intervals.

3. The automatic noise reduction magnetostrictive guided wave monitoring transducer according to claim 1, characterized in that: The adder (8) includes an operational amplifier (14), a first input resistor R1, a second input resistor R2, a balancing resistor R3, and a feedback resistor R. f One end of the first input resistor R1 is led out as the first input port of the adder (8), and one end of the second input resistor R2 is led out as the second input port of the adder (8). The other ends of the first input resistor R1 and the second input resistor R2 are connected in parallel. The circuit after the first input resistor R1 and the second input resistor R2 are connected to the feedback resistor R. f One end is connected to one input port of the operational amplifier (14), and the feedback resistor R f The other end is connected to the output port of the operational amplifier (14) and serves as the output port of the adder (8). One end of the balancing resistor R3 is connected to the other input port of the operational amplifier (14), and the other end of the balancing resistor R3 is grounded.

4. The automatic noise reduction magnetostrictive guided wave monitoring transducer according to claim 2, characterized in that: The transducer is provided with two sets of damping springs (13). One set of damping springs (13) is placed on the electromagnetic backing layer of the electromagnetic noise receiving sensor (3), and the other set of damping springs (13) is placed on the excitation backing layer of the excitation sensor (5). The sensor housing (4) is placed on the damping springs (13).

5. The automatic noise reduction magnetostrictive guided wave monitoring transducer according to claim 3, characterized in that: The excitation sensor (5) is connected to one end of the inverter (7), the other end of the inverter (7) is connected to the first input port of the adder (8), the electromagnetic noise receiving sensor (3) is connected to the second input port of the adder (8), and the output port of the adder (8) is connected to the external waveguide detection device (9) through the cable (10).

6. The automatic noise reduction magnetostrictive guided wave monitoring transducer according to claim 3, characterized in that: The resistance value of the balancing resistor R3 is obtained by the following method: R3=1 / ((1 / R1)+(1 / R2)+(1 / R f )) Where R1 represents the resistance value of the first input resistor, R2 represents the resistance value of the second input resistor, and R... f R1 represents the resistance value of the feedback resistor, and R2 represents the resistance value of the balancing resistor.

7. The automatic noise reduction magnetostrictive guided wave monitoring transducer according to claim 2, characterized in that: The electromagnetic backing layer and the excitation backing layer are made of non-ferromagnetic materials with a thickness of 0.8 mm to 1.2 mm.

8. The automatic noise reduction magnetostrictive guided wave monitoring transducer according to claim 2, characterized in that: The magnetostrictive tape (6) is made of iron-cobalt-nickel alloy material with a thickness of 1mm to 2mm. The pad (2) is made of aluminum alloy material. The thickness of the pad (2) is the same as the thickness of the magnetostrictive tape (6).

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