Construction and installation method for fiber bragg grating temperature sensor

Abstract

The invention relates to a construction and installation method for a fiber grating temperature sensor, and belongs to the technical field of optical fiber sensing. Designing a polyimide single-sided sub-sensitive adhesive tape according to the boundary dimension of the sensor; horizontally placing the sensor on the surface of the structure, and bonding and fixing the sensor on the surface of the structure through a polyimide single-side sensitive adhesive tape; calculating the fixing force F1 of the polyimide single-side sensitive adhesive tape to the sensor, and judging whether the fixing force F1 is greater than or equal to a preset threshold value; 4, fixing the edge of the polyimide single-side sensitive adhesive tape on the upper surface of the structure through an adhesive; 5, calculating the fixing force F2 of the adhesive; after curing, construction and installation are completed; the problems of unstable performance and poor repeatability of the temperature sensor caused by mutual interference of environment temperature and fixed stress in the working process of the sensor are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber sensing and relates to a construction and installation method of an optical fiber Bragg grating temperature sensor. Background Art

[0002] Because fiber Bragg grating temperature sensors exhibit both stress and temperature effects, achieving accurate temperature measurement requires ensuring that the stress effect is zero during operation. Currently, the most common method for securing sensors in the industry is to use silicone rubber or epoxy adhesive. However, this method directly creates mechanical stress between the sensor and the surface through the adhesive, affecting the linear temperature effect and significantly reducing the temperature sensor's measurement accuracy. To ensure accurate temperature sensor measurements, developing a stress-free sensor mounting method is a primary challenge that must be addressed. Summary of the Invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and propose a construction and installation method for a fiber grating temperature sensor, which solves the problem of unstable performance and poor repeatability of the temperature sensor caused by the mutual interference of ambient temperature and fixed stress during operation of the sensor.

[0004] The solution of the present invention is:

[0005] A method for constructing and installing a fiber Bragg grating temperature sensor, comprising:

[0006] Step 1: Place the rectangular sensor horizontally; the cross section of the sensor is square; design a polyimide single-sided subtly adhesive tape according to the outer dimensions of the sensor;

[0007] Step 2: Place the sensor horizontally on the surface of the structure and fix the sensor to the surface of the structure with a polyimide single-sided adhesive tape;

[0008] Step 3: Calculate the fixing force F1 of the polyimide single-sided sub-sensitive tape on the sensor, and determine whether the fixing force F1 is greater than or equal to a preset threshold. If it is greater than or equal to the preset threshold, proceed to step 4; otherwise, return to step 1 and redesign the polyimide single-sided sub-sensitive tape.

[0009] Step 4: Fix the edge of the polyimide single-sided acrylonitrile tape to the upper surface of the structure by adhesive;

[0010] Step 5: Calculate the fixing force F2 of the adhesive; determine whether the fixing force F2 is greater than or equal to a preset threshold. If so, proceed to step 6; otherwise, return to step 4 and reapply the adhesive.

[0011] Step 6: After curing, complete the construction and installation.

[0012] In the above-mentioned method for constructing and installing a fiber Bragg grating temperature sensor, in step one, the polyimide single-sided isocyanate tape has a rectangular structure; the length of the polyimide single-sided isocyanate tape is greater than or equal to the length of the sensor; and the width of the polyimide single-sided isocyanate tape is greater than the width of the sensor.

[0013] In the above-mentioned fiber Bragg grating temperature sensor installation method, the width of the polyimide single-sided acrylonitrile tape is set to L2, the width of the sensor is set to L1, and the height of the sensor is set to H1. The calculation method for the width L2 of the polyimide single-sided acrylonitrile tape is:

[0014]

[0015] Where B is the single-sided adhesive width.

[0016] In the above-mentioned fiber Bragg grating temperature sensor construction and installation method, the middle part of the polyimide single-sided sub-sensitive tape is not coated with adhesive; 1.9-2.1mm wide adhesive is coated on both sides of the width direction of the polyimide single-sided sub-sensitive tape, that is, the single-sided adhesive width B is 1.9-2.1mm.

[0017] In the above-mentioned method for constructing and installing a fiber Bragg grating temperature sensor, in step 2, the middle part of the polyimide single-sided isocyanate tape contacts the upper surface of the sensor; both sides of the polyimide single-sided isocyanate tape in the width direction are bonded to the upper surface of the structure; after fixation, the polyimide single-sided isocyanate tape is in a trapezoidal stretched state.

[0018] In the above-mentioned method for installing a fiber Bragg grating temperature sensor, in step 3, the calculation method of the fixing force F1 is:

[0019] F1=τ1·2B

[0020] Where τ1 is the shear strength of the polyimide single-sided acrylonitrile tape, N / mm.

[0021] In the above-mentioned method for constructing and installing a fiber Bragg grating temperature sensor, when F1 is less than a preset threshold, the process returns to step 1 and increases the single-side gluing width B.

[0022] In the above-mentioned method for constructing and installing a fiber Bragg grating temperature sensor, the adhesive is silicone rubber, and the widthwise edges of the polyimide single-sided sub-sensitive tape are bonded to the upper surface of the structure through the silicone rubber.

[0023] In the above-mentioned fiber Bragg grating temperature sensor construction and installation method, in step 5, the calculation method of the fixing force F2 is:

[0024] F2=τ2×A

[0025] Where, τ2 is the shear strength of silicone rubber, N / mm;

[0026] A is the area of ​​silicone rubber bonded to the surface of the structure;

[0027] When the fixing force F2 is less than the preset threshold, return to step 4 and increase the area A of the silicone rubber bonded to the surface of the structure.

[0028] In the above-mentioned fiber Bragg grating temperature sensor construction and installation method, in step six, the curing parameters are: 15°C-18°C, standing for 2 days; 19°C-22°C, standing for 2 days; 23°C-24°C, standing for 3 days to complete curing.

[0029] The beneficial effects of the present invention compared with the prior art are:

[0030] (1) The present invention achieves zero stress on the temperature-sensitive direction of the sensor by fixing the sensor with a polyimide single-sided subtly sensitive tape, thereby avoiding the influence of mechanical stress on the temperature effect;

[0031] (2) The present invention increases the reliability of tape installation by fixing the edge of the polyimide single-sided subtly adhesive tape with silicone rubber;

[0032] (3) The present invention solves the problem of mutual interference between ambient temperature and mechanical stress during operation of the temperature sensor, thereby improving the measurement accuracy of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the sensor structure of the present invention;

[0034] Figure 2 Schematic diagram of the polyimide single-sided acrylonitrile tape of the present invention;

[0035] Figure 3 This is a schematic diagram of the polyimide single-sided acrylonitrile tape used in the present invention bonding and fixing the sensor to the surface of the structure;

[0036] Figure 4 This is a schematic diagram of fixing the edge of the polyimide single-sided subtly adhesive tape on the surface of the structure by adhesive. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the embodiments.

[0038] The present invention provides a method for installing a fiber Bragg grating temperature sensor. By using a single-sided polyimide acrylonitrile tape with no adhesive on the sensor contact surface to secure the sensor to a structural surface, zero stress is achieved in the temperature-sensitive direction of the sensor, preventing the effects of installation stress on sensor stability, repeatability, and other performance characteristics. By using silicone rubber to secure the edge of the single-sided polyimide acrylonitrile tape, the reliability of the tape installation is increased, the quality risk of tape warping due to temperature cycling is avoided, and installation reliability is improved. This method solves the problem of unstable temperature sensor performance and poor repeatability caused by the interference between ambient temperature and fixing stress during operation.

[0039] The fiber Bragg grating temperature sensor installation method includes the following steps:

[0040] Step 1: Place the sensor 1 with rectangular structure horizontally, as shown in the following example: Figure 1 As shown, the cross section of the sensor 1 is square; the polyimide single-sided acrylonitrile tape 2 is designed according to the dimensions of the sensor 1. The sensor weighs less than 1 gram.

[0041] like Figure 2 As shown, the polyimide single-sided isocyanate tape 2 is a rectangular structure; the length of the polyimide single-sided isocyanate tape 2 is greater than or equal to the length of the sensor 1; and the width of the polyimide single-sided isocyanate tape 2 is greater than the width of the sensor 1.

[0042] The width of the polyimide single-sided acrylonitrile tape is determined by the sensor width, sensor height, and bonding width. Assume the width of the polyimide single-sided acrylonitrile tape 2 is L2, the width of the sensor 1 is L1, and the height of the sensor 1 is H1; the calculation method for the width L2 of the polyimide single-sided acrylonitrile tape 2 is:

[0043]

[0044] Where B is the single-sided adhesive width.

[0045] The middle of the polyimide single-sided acrylonitrile tape 2 is not coated with adhesive; both sides of the width direction of the polyimide single-sided acrylonitrile tape 2 are coated with 1.9-2.1mm wide adhesive, that is, the unilateral adhesive width B is 1.9-2.1mm.

[0046] In the present invention, the polyimide single-sided subtlynic tape 2 is coated with adhesive only on two sides, and no adhesive is coated in the middle, and the single-side bonding width is 1.9-2.1 mm.

[0047] Step 2: Place the sensor 1 horizontally on the surface of the structure and fix the sensor 1 on the surface of the structure with the polyimide single-sided acrylonitrile tape 2. Figure 3As shown, the middle of the polyimide single-sided acrylonitrile tape 2 contacts the upper surface of the sensor 1; both sides of the polyimide single-sided acrylonitrile tape 2 in the width direction are bonded to the upper surface of the structure; after being fixed, the polyimide single-sided acrylonitrile tape 2 is in a trapezoidal stretched state.

[0048] Step 3: Calculate the fixing force F1 of the polyimide single-sided sub-sensitive tape 2 on the sensor 1, and determine whether the fixing force F1 is greater than or equal to the preset threshold. If it is greater than or equal to the preset threshold, proceed to step 4; otherwise, return to step 1 to redesign the polyimide single-sided sub-sensitive tape 2.

[0049] The calculation method of the fixing force F1 is:

[0050] F1=τ1·2B

[0051] Wherein, τ1 is the shear strength of the polyimide single-sided acrylonitrile tape 2, N / mm.

[0052] When F1 is less than the preset threshold, return to step 1 and increase the single-side adhesive width B.

[0053] Step 4: Fix the edge of the polyimide single-sided acrylonitrile tape 2 on the upper surface of the structure by adhesive, such as Figure 4 As shown. The adhesive is made of silicone rubber, which meets the requirements of space environment. The width edges of the polyimide single-sided acrylonitrile tape 2 are bonded to the upper surface of the structure through the silicone rubber.

[0054] The role of the silicone rubber used in the present invention is to fix the polyimide single-sided acrylonitrile tape to prevent the tape from warping due to temperature cycling and losing its fixing function.

[0055] Step 5: Calculate the fixing force F2 of the adhesive; determine whether the fixing force F2 is greater than or equal to a preset threshold. If so, proceed to step 6; otherwise, return to step 4 and re-apply the adhesive.

[0056] The calculation method of the fixing force F2 is:

[0057] F2=τ2×A

[0058] Where, τ2 is the shear strength of silicone rubber, N / mm;

[0059] A is the area of ​​silicone rubber bonded to the surface of the structure;

[0060] When the fixing force F2 is less than the preset threshold, return to step 4 and increase the area A of the silicone rubber bonded to the surface of the structure.

[0061] Step 6: After curing, complete the construction and installation.

[0062] Curing parameters are: 15℃-18℃, stand for 2 days; 19℃-22℃, stand for 2 days; 23℃-24℃, stand for 3 days to complete the curing. Vibration test cannot be performed during the stand period.

[0063] Fiber Bragg grating temperature sensors have both stress and temperature effects. Both stress and temperature changes can cause changes in the sensor output. If stress effects are introduced into the temperature sensor, the measurement accuracy of the temperature sensor will decrease. Therefore, it is necessary to eliminate the stress effects during the temperature sensor measurement process by studying the installation method to achieve the purpose of temperature measurement.

[0064] Traditional mounting methods use silicone rubber or epoxy adhesive to directly secure the sensor to the surface of the structure. However, when the ambient temperature changes, mechanical stress is transmitted to the sensor through the adhesive due to the different thermal expansion coefficients between the sensor metal and the structural metal, causing changes in the sensor's shape and output, resulting in a decrease in sensor measurement accuracy. This invention, using single-sided polyimide acrylonitrile tape to secure the sensor, addresses the challenges of unstable temperature sensor performance and poor repeatability caused by the mutual interference between ambient temperature and securing stress during operation, enabling precise measurement of fiber Bragg grating temperature sensors.

[0065] By using polyimide single-sided subtended tape to secure the sensor, this invention achieves zero stress in the temperature-sensitive direction, eliminating the impact of mounting stress on sensor stability, repeatability, and other performance characteristics. Using silicone rubber to secure the edges of the polyimide single-sided subtended tape increases tape installation reliability and avoids the quality risk of tape warping due to temperature cycling. This approach addresses the challenges of unstable temperature sensor performance and poor repeatability caused by interference between ambient temperature and mounting stress during operation.

[0066] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A method for installing a fiber Bragg grating temperature sensor, characterized in that: include: Step 1: Place the sensor (1) with a rectangular structure in an axially horizontal direction; the cross section of the sensor (1) is a square; and design a polyimide single-sided subtly adhesive tape (2) according to the outer dimensions of the sensor (1); Step 2: Place the sensor (1) horizontally on the surface of the structure, and adhere the sensor (1) to the surface of the structure using a polyimide single-sided adhesive tape (2); Step 3: Calculate the fixing force F1 of the polyimide single-sided sub-sensitive adhesive tape (2) on the sensor (1), and determine whether the fixing force F1 is greater than or equal to a preset threshold value. If it is greater than or equal to the preset threshold value, proceed to step 4; otherwise, return to step 1 to redesign the polyimide single-sided sub-sensitive adhesive tape (2); Step 4: fix the edge of the polyimide single-sided acrylonitrile tape (2) to the upper surface of the structure by adhesive; Step 5: Calculate the fixing force F2 of the adhesive; determine whether the fixing force F2 is greater than or equal to a preset threshold. If so, proceed to step 6; otherwise, return to step 4 and reapply the adhesive. Step 6: After curing, complete the construction and installation.

2. The method for installing a fiber Bragg grating temperature sensor according to claim 1, wherein: In the step 1, the polyimide single-sided subtly adhesive tape (2) has a rectangular structure; the length of the polyimide single-sided subtly adhesive tape (2) is greater than or equal to the length of the sensor (1); and the width of the polyimide single-sided subtly adhesive tape (2) is greater than the width of the sensor (1).

3. The method for constructing and installing a fiber Bragg grating temperature sensor according to claim 2, wherein: Assuming that the width of the polyimide single-sided acrylonitrile adhesive tape (2) is L2, the width of the sensor (1) is L1, and the height of the sensor (1) is H1, the calculation method of the width L2 of the polyimide single-sided acrylonitrile adhesive tape (2) is: Where B is the single-sided adhesive width.

4. The method for installing a fiber Bragg grating temperature sensor according to claim 3, wherein: The middle of the polyimide single-sided acrylonitrile tape (2) is not coated with adhesive; adhesive with a width of 1.9-2.1 mm is coated on both sides of the polyimide single-sided acrylonitrile tape (2) in the width direction, that is, the single-side adhesive width B is 1.9-2.1 mm.

5. The method for constructing and installing a fiber Bragg grating temperature sensor according to claim 4, characterized in that: In the second step, the middle of the polyimide single-sided isocyanate tape (2) contacts the upper surface of the sensor (1); both sides of the polyimide single-sided isocyanate tape (2) in the width direction are bonded to the upper surface of the structure; after being fixed, the polyimide single-sided isocyanate tape (2) is in a trapezoidal stretched state.

6. The method for constructing and installing a fiber Bragg grating temperature sensor according to claim 4, characterized in that: In step 3, the calculation method of the fixing force F1 is: F1=τ1·2B Wherein, τ1 is the shear strength of the polyimide single-sided acrylonitrile tape (2), N / mm.

7. A method for constructing and installing a fiber Bragg grating temperature sensor according to claim 6, characterized in that: When F1 is less than the preset threshold, return to step 1 and increase the single-side adhesive width B.

8. The method for constructing and installing a fiber Bragg grating temperature sensor according to claim 5, wherein: The adhesive is silicone rubber, and the width side edges of the polyimide single-sided acrylonitrile tape (2) are bonded to the upper surface of the structure through the silicone rubber.

9. A method for constructing and installing a fiber Bragg grating temperature sensor according to claim 8, characterized in that: In step 5, the calculation method of the fixing force F2 is: F2=τ2×A Where, τ2 is the shear strength of silicone rubber, N / mm; A is the area of ​​silicone rubber bonded to the surface of the structure; When the fixing force F2 is less than the preset threshold, return to step 4 and increase the area A of the silicone rubber bonded to the surface of the structure.

10. The method for constructing and installing a fiber Bragg grating temperature sensor according to claim 1, characterized in that: In step six, the curing parameters are: 15°C-18°C, standing for 2 days; 19°C-22°C, standing for 2 days; 23°C-24°C, standing for 3 days to complete the curing.

Images