Galvanic corrosion monitoring fiber bragg grating sensor based on electromagnetic induction, production process and use method

Abstract

The invention relates to the technical field of natural environment testing and monitoring, in particular to a galvanic corrosion monitoring fiber bragg grating sensor based on electromagnetic induction, a production process and a use method, the surface of a strain gauge is connected with a strain fiber bragg grating, and a temperature compensation fiber bragg grating is fixed on the side wall in a base. The production process of the galvanic corrosion monitoring fiber bragg grating sensor based on electromagnetic induction comprises the following steps: mounting the strain fiber bragg grating on the strain gauge, connecting the magnetic induction coil with the galvanic corrosion probe, and fixing the strain gauge with the base. The use method of the galvanic corrosion monitoring fiber bragg grating sensor based on electromagnetic induction comprises the following steps: compensating the sensor by using a temperature value to obtain a wavelength variation generated by strain of a strain gauge, and carrying out corrosion rate calibration in a laboratory environment by combining with standard metal to obtain the corrosion rate of the fiber bragg grating sensor. The relation between the corrosion rate and the wavelength variation of the strain fiber grating can be obtained, so that the metal corrosion rate can be obtained, the sensor precision is high, the monitoring difficulty is low, and distributed detection can be realized.

Description

TECHNICAL FIELD

[0001] The application relates to the field of natural environment testing and monitoring, and particularly relates to an electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor, a production process and a use method. BACKGROUND

[0002] A large number of dissimilar metal connections exist in the connecting structures of ships, aircrafts, vehicles and the like, and galvanic corrosion occurs, especially in hidden parts and positions difficult to maintain, and the galvanic corrosion is serious, and the galvanic corrosion is a slow and continuous process, and the galvanic corrosion is a long-term cumulative effect, and the commonly used corrosion monitoring technologies mainly include a coupon weight loss method, an electric resistance probe, an alternating current impedance monitoring technology and the like; the coupon weight loss method needs to be detected in a laboratory, is low in efficiency, and therefore electric signal monitoring methods are usually used for monitoring.

[0003] The existing technologies usually adopt an electric signal monitoring method to monitor the corrosion rate, but the electric signal detection method is difficult to implement multi-point distributed monitoring, and the reliability and safety are difficult to guarantee, especially in an aircraft, a live equipment is generally not allowed to be installed, and the live equipment has an influence on the equipment itself, and it is difficult to implement distributed monitoring. SUMMARY

[0004] In view of the problems in the background art, the application aims to provide an electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor, a production process and a use method.

[0005] The application adopts the following technical scheme.

[0006] The application adopts the following technical scheme.

[0007] In order to guarantee the accuracy of strain monitoring, the distance between the strain gauge and the magnetic induction coil is 1.5 mm.

[0008] In order to avoid the mutual interference of the strain fiber grating and the temperature compensation fiber grating in physical action and signal sensing, the distance between the strain fiber grating and the temperature compensation fiber grating is 80-100 mm.

[0009] In order to avoid signal crosstalk and ensure the stability of distributed detection, the wavelength of the strain fiber grating and the temperature compensation fiber grating is between 1528nm and 1568nm, and the wavelength of the strain fiber grating and the temperature compensation fiber grating in the same optical fiber channel is not repeated, and the wavelength interval is more than 2nm.

[0010] A production process step of an electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor includes: Step 1, place the strain gauge on the horizontal workbench, place the strain fiber grating in the groove of the strain gauge, and drop the glue to fix the strain fiber grating with the right point of the strain gauge; Step 2, after dropping the glue, place the strain gauge on the heating table for heating to complete the fixation of one end of the strain fiber grating; Step 3, use M3 screws to vertically fix the strain gauge on the tool, use a 200g weight under the optical fiber connected to the strain fiber grating, ensure that the weight is suspended during loading, and then use glue on the left point of the strain gauge to fix the other end of the strain fiber grating; Step 4, after waiting for 10 hours for natural curing, remove the strain gauge; Step 5, install the magnetic induction coil inside the base, and connect the two ends of the magnetic induction coil to the two poles of the galvanic corrosion probe through wires; Step 6, install the strain gauge on the M3 threaded hole of the base; Step 7, install the upper cover on the base.

[0011] Preferably, the temperature of the heating table during heating is 100℃, and the heating time is 20min.

[0012] A use method step of an electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor includes: Step 1, calibrate the sensor using temperature values to obtain the relationship between the corresponding temperature compensation fiber grating wavelength change and the temperature change value, and record the temperature compensation fiber grating wavelength change as ; Step 2, connect or connect different electromagnetic induction-based galvanic corrosion monitoring fiber grating sensors in series or parallel, and install them to the position to be monitored, integrate the data through an optical splitter, and access a demodulator; Step 3, monitor the strain fiber grating wavelength change and the temperature compensation fiber grating wavelength change in real time, and record the strain fiber grating wavelength change as ; Step 4, by obtain the wavelength change caused by strain ; Step 5, the corrosion rate can be obtained by calibrating the current value and the wavelength.

[0013] In order to facilitate the determination of the relationship between the temperature compensation fiber grating wavelength variation and the temperature variation value, the functional relationship between the temperature compensation fiber grating wavelength variation and the temperature variation value is Wherein x is the temperature compensation fiber grating wavelength variation, unit: nm; The temperature variation value is ℃.

[0014] Beneficial effects: compared with the prior art, the core problem of data deviation caused by temperature fluctuation in traditional corrosion monitoring is solved, the basic data error of corrosion rate calculation is significantly reduced, the stability of long-term monitoring is ensured, and the interference of the electromagnetic environment of the equipment itself such as ship and aircraft on the monitoring signal is fundamentally avoided; At the same time, the signal crosstalk between multiple sensors is avoided, the monitoring demand of multiple points and no dead angle of large equipment is met, and the defects of single-point monitoring and low efficiency of traditional coupon weight loss method are made up. The production process of the sensor does not need complex laboratory post-processing (such as sampling and weighing of coupon weight loss method), which greatly reduces the difficulty of on-site monitoring, improves the detection efficiency, standardizes the process, and is simple to operate, which reduces the application threshold. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0016] Figure 1 is a top view of the electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor of the present application.

[0017] Figure 2 is a A-A line structure sectional view of Figure 1 of the present application.

[0018] Figure 3 is a top view of the strain gauge of the electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor of the present application.

[0019] Figure 4 is a side view of the strain fiber grating and strain gauge connection of the electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor of the present application.

[0020] Figure 5 is a relationship diagram of the temperature compensation fiber grating wavelength variation and the temperature variation value when the temperature value is used to calibrate the sensor in embodiment 4 of the present application.

[0021] 1 - upper cover, 2 - base, 3 - galvanic corrosion probe, 4 - magnetic induction coil, 5 - wire, 6 - strain gauge, 7 - strain fiber grating, 8 - fiber joint, 9 - temperature compensation fiber grating, 10 - tooling, 11 - M3 screw, 12 - weight loading, 13 - optical fiber, 14 - glue fixing point. DETAILED DESCRIPTION

[0022] The technical solutions in the application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application. Embodiment 1

[0023] In combination Figures 1-3 As shown in the figure, an electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor includes an upper cover 1 and a base 2, the upper cover 1 is fixed above the base 2, characterized in that: the outer side of the upper cover 1 is connected with a galvanic corrosion probe 3, the base 2 is internally provided with a magnetic induction coil 4, both poles of the galvanic corrosion probe 3 are connected with wires 5, both ends of the magnetic induction coil 4 are connected with the two poles of the galvanic corrosion probe 3 through the wires 5, the upper side of the magnetic induction coil 4 is provided with a strain gauge 6, the surface of the strain gauge 6 is connected with a strain fiber grating 7, one end of the strain fiber grating 7 is connected with a fiber joint 8, the sidewall inside the base 2 is fixed with a temperature compensation fiber grating 9, and the strain fiber grating 7 is connected with the temperature compensation fiber grating 9 through an optical fiber 13.

[0024] The distance between the strain gauge 6 and the magnetic induction coil 4 is 1.5 mm.

[0025] The distance between the strain fiber grating 7 and the temperature compensation fiber grating 9 is 80-100 mm.

[0026] The wavelength of the strain fiber grating 7 and the temperature compensation fiber grating 9 is between 1528 nm and 1568 nm, the wavelength of the strain fiber grating 7 and the temperature compensation fiber grating 9 in the same fiber channel is not repeated, and the wavelength interval is above 2 nm. Embodiment 2

[0027] In combination Figures 3-4 As shown in the figure, the production process steps of the electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor include: Step 1: Place the strain gauge 6 on a horizontal workbench, place the strain fiber grating 7 in the groove of the strain gauge 6, and drop glue to fix the strain fiber grating 7 and the right point of the strain gauge 6; Step 2, after dropping the glue, place the strain gauge 6 on the heating table for heating to complete the fixation of one end of the strain fiber grating 7; Step 3, use M3 screws 11 to vertically fix the strain gauge 6 on the tool 10, and use a 200g weight load 12 under the optical fiber 13 connected to the strain fiber grating 7, and ensure that the weight is suspended during loading, and then use glue on the left point of the strain gauge 6 to fix the other end of the strain fiber grating 7; Step 4, after waiting for 10 hours for natural curing, remove the strain gauge 6; Step 5, install the magnetic induction coil 4 inside the base 2, and connect the two ends of the magnetic induction coil 4 to the two poles of the galvanic corrosion probe 3 through the wires 5; Step 6, install the strain gauge 6 on the M3 threaded hole of the base 2; Step 7, install the upper cover 1 on the base 2.

[0028] Wherein, the temperature of the heating table during heating is 100℃, and the heating time is 20min. Example 3

[0029] A method for using an electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor includes the following steps: Step 1, calibrate the sensor using temperature values to obtain the relationship between the corresponding temperature compensation fiber grating 9 wavelength change and the temperature change value, and record the temperature compensation fiber grating 9 wavelength change as ; Step 2, connect or connect different electromagnetic induction-based galvanic corrosion monitoring fiber grating sensors in series or parallel, and install them to the position to be monitored, integrate the data through an optical splitter, and access a demodulator; Step 3, monitor the strain fiber grating 7 wavelength change and the temperature compensation fiber grating 9 wavelength change in real time, and record the strain fiber grating 7 wavelength change as ; Step 4, by get the wavelength change caused by strain ; Step 5, by calibrating the relationship between current value and wavelength, the size of the corrosion rate can be obtained.

[0030] Wherein, the functional relationship between the temperature compensation fiber grating 9 wavelength change and the temperature change value is , wherein x is the temperature compensation fiber grating 9 wavelength change, unit: nm; is the temperature change value, unit: ℃.

[0031] Using the scheme described in this embodiment, when the galvanic corrosion probe 3 comes into contact with the current generated by galvanic corrosion, the current is conducted to the magnetic induction coil 4 through the wire 5. At this time, the magnetic induction coil 4 generates an induced magnetic field, causing strain in the strain gauge 6, thereby changing the wavelength within the strained fiber grating 7 (the amount of wavelength change within the strained fiber grating 7 during this process is...). Temperature changes can also cause wavelength changes within the strain fiber grating 7, which can affect measurements during actual use. To improve stability and accuracy, the relationship between the wavelength change of the temperature-compensated fiber grating 9 and the temperature change was obtained by calibrating the sensor using temperature values. The wavelength change of the temperature-compensated fiber grating 9 was then recorded as... During the actual monitoring process, the measured wavelength changes of the strain fiber grating were recorded as follows: ,pass The wavelength change caused by strain can then be obtained. By eliminating the influence of temperature on accurate values, the corrosion rate can be accurately obtained by calibrating the relationship between the current value and the wavelength. The sensor of this invention effectively eliminates the influence of ambient temperature changes on the monitoring results, improves the stability and reliability of the data, and improves the accuracy of corrosion rate monitoring. In addition, the sensor uses optical fiber 13 and does not rely on electrical signals for data transmission, which can completely avoid the influence of electromagnetic interference on the monitoring results.

[0032] When connecting the strain fiber grating 7 and the strain gauge 6, first place the strain gauge 6 on a horizontal workbench and place the strain fiber grating 7 in the groove of the strain gauge 6. Fix it with 353ND glue (a special glue for fiber curing) at the glue fixing point 14 on the right side of the strain gauge 6. Then, place the strain gauge 6 and the strain fiber grating 7 in the groove together on a heating table and heat it to 100℃ for 20 minutes. After fixing one end of the strain fiber grating 7 (the end near the glue fixing point 14 on the right side), use M3 screws 11 to vertically fix the strain gauge 6 on the fixture 10. Use a 200g weight 12 to load 12 below the fiber optic cable 13 connected to the strain fiber grating 7, and ensure that the weight is suspended during loading. Then, drip 353ND glue into the glue fixing point 14 on the left side of the strain gauge 6. After 10 hours of natural curing, remove the strain gauge 6 from the fixture 10 to complete the connection between the strain fiber grating 7 and the strain gauge 6. Example 4

[0033] Combination Figure 5When calibrating the sensor for temperature, the calibration can be performed according to the actual temperature value used. In this embodiment, six points are selected for the temperature compensation sensor calibration: 25℃, 30℃, 35℃, 40℃, 45℃, and 50℃. After calibration, the corresponding wavelength change is obtained, and the correlation between the wavelength change and the temperature change value of the temperature compensation fiber grating 9 is fitted in Origin (i.e.,...). Where x represents the wavelength change of the temperature-compensated fiber grating in nm; (This is the temperature change value, in °C).

[0034] The fiber Bragg grating sensor for galvanic corrosion monitoring based on electromagnetic induction of this invention not only solves the core problem of data deviation caused by temperature fluctuations in traditional corrosion monitoring, significantly reducing the error of the basic data for corrosion rate calculation and ensuring the stability of long-term monitoring, but also fundamentally avoids interference from the electromagnetic environment of equipment such as ships and aircraft on the monitoring signal. Simultaneously, it avoids signal crosstalk between multiple sensors, meeting the monitoring needs of large equipment at multiple points without blind spots, and overcoming the shortcomings of traditional single-point monitoring and low efficiency of the weightlessness method. The sensor's manufacturing process does not require complex laboratory post-processing (such as sampling and weighing in the weightlessness method), greatly reducing the difficulty of on-site monitoring, improving detection efficiency, and the standardized and simple operation of the process lowers the application threshold.

[0035] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. An electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor, comprising an upper cover (1) and a base (2), the upper cover (1) is fixed above the base (2), characterized in that: The outer side of the upper cover (1) is connected with the galvanic corrosion probe (3), the inside of the base (2) is provided with the magnetic induction coil (4), both poles of the galvanic corrosion probe (3) are connected with the wire (5), both ends of the magnetic induction coil (4) are connected with both poles of the galvanic corrosion probe (3) through the wire (5), the upper side of the magnetic induction coil (4) is provided with the strain gauge (6), the surface of the strain gauge (6) is connected with the strain fiber grating (7), one end of the strain fiber grating (7) is connected with the fiber joint (8), the sidewall inside the base (2) is fixed with the temperature compensation fiber grating (9), and the strain fiber grating (7) is connected with the temperature compensation fiber grating (9) through the fiber (13).

2. The electromagnetic induction based galvanic corrosion monitoring fiber Bragg grating sensor of claim 1, wherein: The distance between the strain gauge (6) and the magnetic induction coil (4) is 1.5 mm.

3. The electromagnetic induction based galvanic corrosion monitoring fiber Bragg grating sensor of claim 2, wherein: The interval between the strain fiber grating (7) and the temperature compensation fiber grating (9) is 80-100 mm.

4. The electromagnetic induction based galvanic corrosion monitoring fiber Bragg grating sensor of claim 2, wherein: The wavelength of the strain fiber grating (7) and the temperature compensation fiber grating (9) is between 1528 nm and 1568 nm, and the wavelength of the strain fiber grating (7) and the temperature compensation fiber grating (9) in the same fiber channel is not repeated, and the wavelength interval is more than 2 nm.

5. The production process of the electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor according to any one of claims 1-4, comprising the following steps: Step 1, place the strain gauge (6) on a horizontal workbench, place the strain fiber grating (7) in the groove of the strain gauge (6), and drop glue to fix the strain fiber grating (7) and the right point of the strain gauge (6); Step 2, after dropping the glue, place the strain gauge (6) on a heating table to heat, and complete the fixation of one end of the strain fiber grating (7); Step 3, use M3 screws (11) to vertically fix the strain gauge (6) on the tooling (10), and use a 200g weight (12) below the fiber (13) connected to the strain fiber grating (7), and ensure that the weight is suspended during loading, and then use glue on the left point of the strain gauge (6) to fix the other end of the strain fiber grating (7); Step 4, after waiting for 10 hours for natural curing, remove the strain gauge (6); Step 5, install the magnetic induction coil (4) inside the base (2), and connect both ends of the magnetic induction coil (4) to both poles of the galvanic corrosion probe (3) through the wire (5); Step 6, install the strain gauge (6) on the M3 threaded hole of the base (2); Step 7, install the upper cover (1) on the base (2).

6. The production process according to claim 5, characterized in that: The temperature of the heating table during heating is 100℃, and the heating time is 20 min.

7. The use method of the electromagnetic induction-based galvanic corrosion monitoring fiber grating sensor according to any one of claims 1-4, comprising the following steps: Step 1, calibrate the sensor using temperature values to obtain the corresponding relationship between the temperature compensation fiber grating (9) wavelength variation and the temperature variation value, and record the temperature compensation fiber grating (9) wavelength variation as ; Step 2, connect different electromagnetic induction-based galvanic corrosion monitoring fiber grating sensors in series or parallel, and install them to the position to be monitored, integrate the data through an optical splitter, and access a demodulator; Step 3, monitor the wavelength variation of the strain fiber grating (7) and the temperature compensation fiber grating (9) in real time, and record the wavelength variation of the strain fiber grating (7) as ; Step 4, by obtaining the amount of wavelength change due to strain ; Step 5, the relationship between the current value and the wavelength can be obtained by calibrating the corrosion rate.

8. The method of use of claim 7, wherein: The functional relationship between the wavelength variation of the temperature-compensated fiber grating (9) and the temperature variation value is wherein x is the wavelength variation of the temperature-compensated fiber grating (9) in nm; is the temperature variation value in °C.

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