Lever-type double-fiber grating pressure sensor and preparation method thereof

Abstract

The invention discloses a lever type double-fiber grating pressure sensor and a preparation method thereof. The sensor comprises a rectangular column shell and a pressure measuring grating assembly installed in the rectangular column shell. An accommodating space is formed in the rectangular column shell; the pressure measuring optical fiber grating assembly comprises a piston, an h-shaped stainless steel tube, a T-shaped lever, a temperature compensation optical fiber grating, a first pressure measuring optical fiber grating and a second pressure measuring optical fiber grating. The piston covers the opening of the rectangular column shell; the h-shaped stainless steel pipe is inversely arranged in the center in the rectangular column shell; the T-shaped lever comprises a long part and a short part; the temperature compensation fiber bragg grating is connected in parallel with the first pressure measurement fiber bragg grating and the second pressure measurement fiber bragg grating through the first optical fiber; and the first pressure measuring fiber grating and the second pressure measuring fiber grating are connected in series through the second optical fiber. The pressure sensor realizes high-sensitivity, quick-response and accurate data measurement, is compact in structure and high in portability, and is suitable for pressure detection requirements in various complex environments.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber sensing, and more particularly to a lever-type dual-fiber grating pressure sensor and a preparation method thereof. Background Art

[0002] Ocean pressure parameters are the basis for obtaining ocean sound speed, flow velocity, density and other parameters. Real-time monitoring of ocean pressure is crucial to the development of marine resources, offshore operations, military defense and other fields. Fiber Bragg grating sensors have gradually become a research hotspot for ocean pressure detection due to their small size, corrosion resistance, and resistance to electromagnetic interference.

[0003] In the existing technology, fiber Bragg grating pressure sensors usually use a single pressure-measuring fiber Bragg grating structure, which has low sensitivity and is difficult to meet the requirements of high sensitivity and fast response at the same time. Although some technologies have been enhanced through polymer packaging or lever structures, there are still problems such as insufficient sensitivity and long response time, which cannot meet the requirements of high-precision pressure detection in shallow waters.

[0004] In addition, the temperature compensation mechanism of existing sensors mostly adopts a series structure, which has limited temperature compensation effect and is easily affected by the external environment, resulting in inaccurate measurement data.

[0005] Existing sensors also have problems with complex structures and large sizes, which are not conducive to carrying and installation. For example, some sensors transmit strain through diaphragms and lever structures. Although they achieve sensitivity enhancement, they have slow response speeds and lack effective waterproof designs. Seawater infiltration may affect the stability and service life of the sensors. These problems limit the widespread application of fiber Bragg grating pressure sensors in ocean exploration.

[0006] Therefore, how to design a fiber Bragg grating pressure sensor with high sensitivity, fast response, excellent temperature compensation effect and compact structure to meet the needs of shallow sea pressure detection is an urgent problem that technicians in this field need to solve. Summary of the invention

[0007] In view of this, the present invention provides a lever-type dual fiber Bragg grating pressure sensor, which effectively solves the defects of the prior art and realizes high-precision and high-stability ocean pressure detection through the symmetrical arrangement of dual pressure-measuring fiber Bragg gratings, polycarbonate packaging, parallel temperature compensation fiber Bragg gratings and polytetrafluoroethylene diaphragm waterproof design.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a lever-type dual fiber Bragg grating pressure sensor, comprising: a rectangular cylindrical shell and a pressure measuring grating assembly installed inside the rectangular cylindrical shell; a containing space is formed inside the rectangular cylindrical shell, the upper end of which is open and the bottom end is provided with a guide hole; the pressure measuring grating assembly comprises: a piston, an H-shaped stainless steel tube, a T-shaped lever, a temperature compensating fiber Bragg grating, a first pressure measuring fiber Bragg grating and a second pressure measuring fiber Bragg grating;

[0010] The piston covers the opening of the rectangular cylindrical shell;

[0011] The H-shaped stainless steel tube is invertedly arranged in the center of the rectangular column shell, and the upper end is welded to the piston;

[0012] The T-shaped lever comprises a horizontally arranged long part and a vertically arranged short part, one end of the long part is welded to two-thirds of the short part to form a T-shaped structure, and the long part is welded to the lower end of the H-shaped stainless steel pipe;

[0013] The temperature compensation fiber Bragg grating is arranged inside the H-shaped stainless steel tube, and is connected in parallel with the first pressure measuring fiber Bragg grating and the second pressure measuring fiber Bragg grating through the first optical fiber;

[0014] The first pressure-measuring fiber Bragg grating and the second pressure-measuring fiber Bragg grating are symmetrically arranged above and below the short portion of the T-shaped lever, and are connected in series via the second optical fiber.

[0015] Further, the pressure measuring grating assembly also includes: a first diaphragm installed horizontally below the piston, and a second diaphragm installed vertically on the right side of the H-shaped stainless steel tube;

[0016] The two ends of the first diaphragm are respectively fixedly connected to the rectangular column shell and the H-shaped stainless steel tube, and the two ends of the second diaphragm are respectively fixedly connected to the rectangular column shell and the long part of the T-shaped lever.

[0017] Furthermore, the first diaphragm and the second diaphragm are made of polytetrafluoroethylene, the first diaphragm is 4 mm long, and the second diaphragm is 14 mm long.

[0018] Furthermore, the first optical fiber and the second optical fiber are coupled to form an output optical fiber, and outputted through a guide hole at the bottom end of the rectangular cylindrical shell.

[0019] Furthermore, the first pressure-measuring fiber Bragg grating and the second pressure-measuring fiber Bragg grating are respectively packaged with a first pressure-sensitive material and a second pressure-sensitive material;

[0020] The first pressure-sensitive material and the second pressure-sensitive material are made of polycarbonate.

[0021] Furthermore, the rectangular column shell is made of 304 stainless steel, the inner wall thickness of the top is 8 mm, and the inner wall thickness of the bottom and surrounding areas is 4 mm.

[0022] Furthermore, the H-shaped stainless steel tube is made of 304 stainless steel, has a height of 14 mm and a width of 6 mm.

[0023] Furthermore, the temperature compensating fiber Bragg grating, the first pressure measuring fiber Bragg grating and the second pressure measuring fiber Bragg grating adopt fiber Bragg gratings with a central wavelength of 1310 nm.

[0024] Furthermore, the piston is made of 7075 aluminum alloy, has a length of 12 mm, a width of 8 mm, and a thickness of 6 mm.

[0025] In a second aspect, the present invention provides a preparation method, which is applied to the above-mentioned lever-type dual fiber Bragg grating pressure sensor, comprising the following steps:

[0026] Material preparation: 304 stainless steel, 7075 aluminum alloy, polytetrafluoroethylene, and polycarbonate materials are selected to process rectangular cylindrical shells, pistons, H-shaped stainless steel tubes, T-shaped levers, and diaphragms based on preset standards;

[0027] Fiber Bragg grating packaging: Select a fiber Bragg grating with a central wavelength of 1310nm, encapsulate the temperature compensation fiber Bragg grating inside the H-shaped stainless steel tube, encapsulate the first pressure measuring fiber Bragg grating and the second pressure measuring fiber Bragg grating in polycarbonate materials respectively, and install them symmetrically above and below the short part of the T-shaped lever 6;

[0028] Component welding and assembly: Use argon arc welding to weld the piston to the H-shaped stainless steel tube and the T-shaped lever, and install the diaphragm under the piston and on the right side of the H-shaped stainless steel tube to ensure that all components are tightly connected and sealed;

[0029] Fiber coupling and export: two pressure-measuring fiber gratings are connected in series through the second optical fiber, and the temperature-compensating fiber grating is connected in parallel with the pressure-measuring fiber grating through the first optical fiber, and coupled at the bottom end of the rectangular cylindrical shell to form an export optical fiber, which is exported through the guide hole;

[0030] Testing and calibration: Use a standard pressure source and temperature control box to perform pressure testing and temperature compensation testing on the assembled sensor to ensure that the pressure sensitivity reaches above 3.05nm / Mpa, the response speed is within 30ms, and its stability and accuracy are verified.

[0031] It can be seen from the above technical solution that compared with the prior art, the technical solution of the present invention has the following advantages:

[0032] Beneficial effects:

[0033] 1. The lever-type dual fiber Bragg grating pressure sensor disclosed in the present invention significantly improves the sensitivity of pressure detection by using dual pressure-measuring fiber Bragg gratings (FBG2 and FBG3) symmetrically arranged above and below the T-shaped lever, combined with the packaging of polymer polycarbonate. At the same time, the design of the piston and the T-shaped lever shortens the pressure response time to less than 30ms, meeting the requirements of high precision and rapid response for shallow sea pressure detection.

[0034] 2. A temperature compensation fiber Bragg grating is set in the H-shaped stainless steel tube and connected in parallel with the pressure measuring fiber Bragg grating, which effectively eliminates the influence of temperature change on pressure measurement and improves the accuracy of detection data. In addition, the design of the polytetrafluoroethylene diaphragm prevents seawater from infiltrating, further enhancing the stability and reliability of the sensor.

[0035] 3. All components are assembled with components less than 20mm in size. The overall structure is compact and easy to carry and install. By adjusting the piston thickness, T-lever material and thickness and other parameters, the sensitivity and response speed of the sensor can be flexibly adjusted, which is suitable for pressure detection in the shallow sea range of 0-800m. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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 embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1 A front view of a lever-type dual fiber Bragg grating pressure sensor provided by an embodiment of the present invention;

[0038] Figure 2 A top view of a lever-type dual fiber Bragg grating pressure sensor provided by an embodiment of the present invention;

[0039] In the figure: 1-rectangular cylindrical shell, 2-piston, 3-first diaphragm, 4-h-type stainless steel tube, 5-first optical fiber, 6-T-type lever, 7-second diaphragm, 8-temperature compensation fiber Bragg grating, 9-second optical fiber, 10-first pressure measuring fiber Bragg grating, 11-first pressure-sensitive material, 12-second pressure-sensitive fiber Bragg grating, 13-second pressure-sensitive material, 14-export optical fiber. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments 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 are within the scope of protection of the present invention.

[0041] Embodiment 1;

[0042] like Figure 1 and Figure 2 As shown, this embodiment provides a lever-type dual fiber Bragg grating pressure sensor, comprising: a rectangular cylindrical shell 1 and a pressure measuring grating assembly installed inside the rectangular cylindrical shell 1;

[0043] A containing space is formed inside the rectangular cylindrical shell 1, the upper end of which is open and the bottom end is provided with a guide hole; the pressure measuring grating assembly comprises: a piston 2, an H-shaped stainless steel tube 4, a T-shaped lever 6, a temperature compensating fiber grating 8, a first pressure measuring fiber grating 10 and a second pressure measuring fiber grating 12;

[0044] The piston 2 covers the opening of the rectangular cylindrical shell 1;

[0045] The h-shaped stainless steel tube 4 is invertedly arranged in the center of the rectangular cylindrical shell 1, and the upper end is welded to the piston 2;

[0046] The T-shaped lever 6 includes a horizontally arranged long portion and a vertically arranged short portion, one end of the long portion is welded to two-thirds of the short portion to form a T-shaped structure, and the long portion is welded to the lower end of the H-shaped stainless steel tube 4;

[0047] The temperature compensation fiber Bragg grating 8 is arranged inside the H-shaped stainless steel tube 4, and is connected in parallel with the first pressure measuring fiber Bragg grating 10 and the second pressure measuring fiber Bragg grating 12 through the first optical fiber 5;

[0048] The first pressure-measuring fiber Bragg grating 10 and the second pressure-measuring fiber Bragg grating 12 are symmetrically arranged above and below the short portion of the T-shaped lever 6 , and are connected in series via the second optical fiber 9 .

[0049] The lever-type dual fiber Bragg grating pressure sensor here significantly improves the sensitivity and response speed of pressure detection (within 30ms) through the symmetrical arrangement of dual pressure-measuring fiber Bragg gratings and polycarbonate packaging. The built-in temperature compensation fiber Bragg grating is connected in parallel with the pressure-measuring fiber Bragg grating to effectively eliminate the temperature effect and ensure data accuracy. The PTFE diaphragm prevents seawater infiltration and enhances stability. The overall structure is compact, the component size is less than 20mm, easy to carry and install, and is suitable for pressure detection in the shallow sea range of 0-800m.

[0050] The following is a further detailed description of each structure of the lever-type dual fiber Bragg grating pressure sensor.

[0051] The pressure measuring grating assembly in this embodiment further includes: a first diaphragm 3 installed horizontally below the piston 2, and a second diaphragm 7 installed vertically on the right side of the H-shaped stainless steel tube 4;

[0052] The two ends of the first diaphragm 3 are fixedly connected to the rectangular column shell 1 and the H-shaped stainless steel tube 4 respectively, and the two ends of the second diaphragm 7 are fixedly connected to the rectangular column shell 1 and the long part of the T-shaped lever 6 respectively.

[0053] The first diaphragm 3 and the second diaphragm 7 are made of polytetrafluoroethylene. The first diaphragm 3 is 4 mm long, and the second diaphragm 7 is 14 mm long.

[0054] Here, the first diaphragm 3 is horizontally installed below the piston 2 to directly block the entry of seawater, while the second diaphragm 7 is vertically installed on the right side of the h-shaped stainless steel tube 4, further enhancing the waterproof effect and preventing seawater from penetrating through the gap between the h-shaped stainless steel tube 4 and the T-shaped lever 6. This double diaphragm design effectively prevents seawater from penetrating into the sensor, ensuring the stability of the pressure-measuring fiber Bragg grating and the accuracy of the detection data.

[0055] At the same time, the first diaphragm 3 and the second diaphragm 7 are both made of polytetrafluoroethylene (PTFE), which has excellent corrosion resistance, waterproofness and elasticity, and is suitable for marine environments. The size design is reasonable, which not only ensures the waterproof effect of the diaphragm, but also does not affect the overall structure and performance of the sensor.

[0056] In this embodiment, the first optical fiber 5 and the second optical fiber 9 are coupled to form an output optical fiber 14, and are output through the guide hole at the bottom end of the rectangular cylindrical shell 1; it uses two independent optical fibers to be responsible for the data transmission of pressure measurement and temperature compensation respectively, which effectively improves the overall performance of the system. One optical fiber is used to connect the dual pressure measurement fiber Bragg grating, and the other optical fiber is used for the temperature compensation fiber Bragg grating. It ensures the independence and stability of signal transmission, reduces mutual interference, and also improves the accuracy and reliability of detection data.

[0057] In this embodiment, the first pressure-measuring fiber Bragg grating 10 and the second pressure-measuring fiber Bragg grating 12 are respectively packaged with a first pressure-sensitizing material 11 and a second pressure-sensitizing material 13; the first pressure-sensitizing material 11 and the second pressure-sensitizing material 13 are made of polycarbonate.

[0058] Polycarbonate has a low Young's modulus and high elasticity, which can effectively amplify the strain response of the fiber Bragg grating and significantly improve the sensitivity of pressure detection. By applying polycarbonate packaging to the pressure-measuring fiber Bragg grating, the sensor can produce a greater deformation when subjected to external pressure, thereby enhancing the wavelength shift of the fiber Bragg grating and improving the accuracy of pressure measurement. In addition, polycarbonate has good corrosion resistance and mechanical strength, and is suitable for marine environments, ensuring the stability and reliability of the sensor in long-term use.

[0059] In this embodiment, the rectangular column shell 1 is made of 304 stainless steel, the inner wall thickness of the top is 8 mm, and the inner wall thickness of the bottom and surrounding areas is 4 mm.

[0060] The h-shaped stainless steel tube 4 is made of 304 stainless steel, has a height of 14 mm and a width of 6 mm.

[0061] The temperature compensating fiber Bragg grating 8, the first pressure measuring fiber Bragg grating 10 and the second pressure measuring fiber Bragg grating 12 use fiber Bragg gratings with a central wavelength of 1310 nm.

[0062] The piston 2 is made of 7075 aluminum alloy, with a length of 12 mm, a width of 8 mm, and a thickness of 6 mm.

[0063] The relevant components are built and assembled using elements with a size of less than 20mm, which makes the entire sensor compact, small, light, easy to carry and install. It is particularly suitable for on-site monitoring tasks in complex environments such as the ocean, and fully demonstrates its technical advantages of compact structure and portability.

[0064] The lever-type dual fiber Bragg grating pressure sensor in this embodiment realizes high-precision pressure detection through the coordinated work of various components. The specific working principle is as follows:

[0065] When the seawater pressure acts on the piston 2, the piston 2 is displaced and the displacement is transmitted to the T-type lever 6 through the H-shaped stainless steel tube 4 welded thereto. The upper and lower parts of the short part of the T-type lever 6 are respectively subjected to tensile and compressive deformation, which drives the symmetrically arranged first pressure-measuring fiber grating 10 and second pressure-measuring fiber grating 12 to deform. Since the first pressure-measuring fiber grating 10 and the second pressure-measuring fiber grating 12 are respectively encapsulated with polycarbonate materials, the strain response can be amplified, and the sensitivity of pressure detection can be significantly improved. The deformation causes the effective refractive index of the fiber grating to change, which in turn causes the shift of its central wavelength. By detecting the wavelength changes of the first pressure-measuring fiber grating 10 and the second pressure-measuring fiber grating 12 through the demodulation device, the magnitude of the external pressure can be accurately calculated.

[0066] At the same time, the temperature compensation fiber Bragg grating 8 is placed inside the h-shaped stainless steel tube 4, is only affected by temperature, and is connected in parallel with the pressure measuring fiber Bragg grating. By detecting the wavelength change of the temperature compensation fiber Bragg grating 8, the influence of temperature on the pressure measuring fiber Bragg grating can be eliminated, ensuring the accuracy of the pressure measurement data. The first diaphragm 3 and the second diaphragm 7 inside the sensor are made of polytetrafluoroethylene, which are horizontally installed below the piston 2 and vertically installed on the right side of the h-shaped stainless steel tube 4 respectively to prevent seawater from infiltrating, ensuring the stability of the pressure measuring fiber Bragg grating and the reliability of the detection data. The second optical fiber 9 is embedded in the groove at the bottom end of the rectangular cylindrical shell 1, and is coupled with the first optical fiber 5 to form an output optical fiber 14, which is output through the guide hole, which simplifies the optical fiber arrangement and ensures the stability of signal transmission. The overall structure is compact, the component size is small, and it is easy to carry and install. It is suitable for pressure detection tasks in the shallow sea range of 0-800m, with high sensitivity, fast response and long-term stability.

[0067] Embodiment 2;

[0068] This embodiment provides a preparation method, which is applied to the lever-type dual fiber Bragg grating pressure sensor in the above embodiment, comprising the following steps:

[0069] Material preparation: 304 stainless steel, 7075 aluminum alloy, polytetrafluoroethylene, and polycarbonate materials are selected to process rectangular cylindrical shells, pistons, H-shaped stainless steel tubes, T-shaped levers, and diaphragms based on preset standards;

[0070] Fiber Bragg grating packaging: Select a fiber Bragg grating with a central wavelength of 1310nm, encapsulate the temperature compensation fiber Bragg grating inside the H-shaped stainless steel tube, encapsulate the first pressure measuring fiber Bragg grating and the second pressure measuring fiber Bragg grating in polycarbonate materials respectively, and install them symmetrically above and below the short part of the T-shaped lever 6;

[0071] Component welding and assembly: Use argon arc welding to weld the piston to the H-shaped stainless steel tube and the T-shaped lever, and install the diaphragm under the piston and on the right side of the H-shaped stainless steel tube to ensure that all components are tightly connected and sealed;

[0072] Fiber coupling and export: two pressure-measuring fiber gratings are connected in series through the second optical fiber, and the temperature-compensating fiber grating is connected in parallel with the pressure-measuring fiber grating through the first optical fiber, and coupled at the bottom end of the rectangular cylindrical shell to form an export optical fiber, which is exported through the guide hole;

[0073] Testing and calibration: Use a standard pressure source and temperature control box to perform pressure testing and temperature compensation testing on the assembled sensor to ensure that the pressure sensitivity reaches above 3.05nm / Mpa, the response speed is within 30ms, and its stability and accuracy are verified.

[0074] This embodiment provides a method for preparing a lever-type dual fiber Bragg grating pressure sensor, which uses materials such as 304 stainless steel, 7075 aluminum alloy, polytetrafluoroethylene and polycarbonate, accurately processes each component and uses argon arc welding for welding to ensure that the sensor structure is tight and sealed. The fiber Bragg grating packaging and coupling design improves the sensitivity of pressure detection and the temperature compensation effect. Finally, the standard pressure source and temperature control box are used for testing and calibration to ensure that the pressure sensitivity of the sensor reaches 3.05nm / Mpa or more, the response speed is within 30ms, and its stability and accuracy are verified.

[0075] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0076] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lever-type dual fiber Bragg grating pressure sensor, characterized in that: include: A rectangular cylindrical shell (1) and a pressure measuring grating assembly installed inside the rectangular cylindrical shell (1); The rectangular cylindrical shell (1) has an accommodation space formed inside, the upper end of which is open and the bottom end of which is provided with a guide hole; the pressure measuring grating assembly comprises: a piston (2), an H-shaped stainless steel tube (4), a T-shaped lever (6), a temperature compensating optical fiber grating (8), a first pressure measuring optical fiber grating (10) and a second pressure measuring optical fiber grating (12); The piston (2) covers the opening of the rectangular cylindrical shell (1); The H-shaped stainless steel tube (4) is invertedly arranged at the center of the rectangular cylindrical shell (1), and the upper end is welded to the piston (2); The T-shaped lever (6) comprises a long portion arranged horizontally and a short portion arranged vertically, one end of the long portion is welded to two-thirds of the short portion to form a T-shaped structure, and the long portion is welded to the lower end of the H-shaped stainless steel pipe (4); The temperature compensation fiber Bragg grating (8) is arranged inside the H-shaped stainless steel tube (4), and is connected in parallel with the first pressure measuring fiber Bragg grating (10) and the second pressure measuring fiber Bragg grating (12) through the first optical fiber (5); The first pressure-measuring fiber Bragg grating (10) and the second pressure-measuring fiber Bragg grating (12) are symmetrically arranged above and below the short portion of the T-shaped lever (6), and are connected in series via the second optical fiber (9).

2. A lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The pressure measuring grating assembly further comprises: a first diaphragm (3) installed horizontally below the piston (2), and a second diaphragm (7) installed vertically on the right side of the H-shaped stainless steel tube (4); The two ends of the first diaphragm (3) are respectively fixedly connected to the rectangular column shell (1) and the H-shaped stainless steel tube (4), and the two ends of the second diaphragm (7) are respectively fixedly connected to the rectangular column shell (1) and the long part of the T-shaped lever (6).

3. The lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The first diaphragm (3) and the second diaphragm (7) are made of polytetrafluoroethylene; the first diaphragm (3) is 4 mm long, and the second diaphragm (7) is 14 mm long.

4. The lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The first optical fiber (5) and the second optical fiber (9) are coupled to form an output optical fiber (14), which is output through a guide hole at the bottom end of the rectangular cylindrical shell (1).

5. The lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The first pressure-measuring optical fiber Bragg grating (10) and the second pressure-measuring optical fiber Bragg grating (12) are respectively packaged with a first pressure-sensitizing material (11) and a second pressure-sensitizing material (13); The first pressure-sensitive material (11) and the second pressure-sensitive material (13) are made of polycarbonate.

6. The lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The rectangular column shell (1) is made of 304 stainless steel, the inner wall thickness of the top is 8 mm, and the inner wall thickness of the bottom and surrounding areas is 4 mm.

7. The lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The H-shaped stainless steel tube (4) is made of 304 stainless steel, has a height of 14 mm and a width of 6 mm.

8. The lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The temperature compensation optical fiber grating (8), the first pressure measuring optical fiber grating (10) and the second pressure measuring optical fiber grating (12) adopt optical fiber gratings with a central wavelength of 1310 nm.

9. The lever-type dual fiber Bragg grating pressure sensor according to claim 1, characterized in that: The piston (2) is made of 7075 aluminum alloy and has a length of 12 mm, a width of 8 mm and a thickness of 6 mm.

10. A preparation method, characterized in that: The lever-type dual fiber Bragg grating pressure sensor according to any one of claims 1 to 9 comprises the following steps: Material preparation: 304 stainless steel, 7075 aluminum alloy, polytetrafluoroethylene, and polycarbonate materials are selected to process rectangular cylindrical shells, pistons, H-shaped stainless steel tubes, T-shaped levers, and diaphragms based on preset standards; Fiber Bragg grating packaging: a fiber Bragg grating with a central wavelength of 1310 nm is selected, and a temperature compensation fiber Bragg grating is packaged inside an H-shaped stainless steel tube, and a first pressure measuring fiber Bragg grating and a second pressure measuring fiber Bragg grating are respectively packaged in a polycarbonate material and symmetrically installed above and below the short part of the T-shaped lever (6); Component welding and assembly: Use argon arc welding to weld the piston to the H-shaped stainless steel tube and the T-shaped lever, and install the diaphragm under the piston and on the right side of the H-shaped stainless steel tube to ensure that all components are tightly connected and sealed; Fiber coupling and export: two pressure-measuring fiber gratings are connected in series through the second optical fiber, and the temperature-compensating fiber grating is connected in parallel with the pressure-measuring fiber grating through the first optical fiber, and coupled at the bottom end of the rectangular cylindrical shell to form an export optical fiber, which is exported through the guide hole; Testing and calibration: Use a standard pressure source and temperature control box to perform pressure testing and temperature compensation testing on the assembled sensor to ensure that the pressure sensitivity reaches above 3.05nm / Mpa, the response speed is within 30ms, and its stability and accuracy are verified.

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