A lever-type dual fiber Bragg grating pressure sensor and its preparation method

Abstract

The present invention discloses a lever-type dual-fiber Bragg grating pressure sensor and its preparation method. The sensor comprises: a rectangular cylindrical shell and a pressure grating assembly installed inside the rectangular cylindrical shell; a receiving space is formed inside the rectangular cylindrical shell; the pressure grating assembly comprises: a piston, an H-shaped stainless steel tube, a T-shaped lever, a temperature-compensating fiber Bragg grating, a first pressure grating, and a second pressure grating; the piston covers the opening of the rectangular cylindrical shell; the H-shaped stainless steel tube is inverted and arranged in the center of the rectangular cylindrical shell; the T-shaped lever comprises a long portion and a short portion; the temperature-compensating fiber Bragg grating is connected in parallel with the first and second pressure gratings via a first optical fiber; and the first and second pressure gratings are connected in series via a second optical fiber. The sensor achieves high sensitivity, fast response, and accurate data measurement, and has a compact structure and strong portability, making it suitable for pressure detection needs in a variety of 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 Bragg grating pressure sensor and a preparation method thereof. Background Art

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

[0003] Existing fiber Bragg grating (FBG) pressure sensors typically utilize a single pressure-measuring fiber Bragg grating (FBG) structure, resulting in low sensitivity and difficulty meeting the requirements for both high sensitivity and fast response. While some technologies enhance sensitivity through polymer encapsulation or lever structures, these still suffer from insufficient sensitivity and long response times, making them inadequate for 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 suffer from complex structures and large size, making them difficult to carry and install. For example, some sensors transmit strain through a diaphragm and lever structure. While this achieves sensitivity enhancement, the response speed is slow and they lack effective waterproofing. Seawater infiltration can affect the sensor's stability and service life. These issues 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 existing technology through the symmetrical arrangement of dual pressure-measuring fiber Bragg gratings, polycarbonate packaging, parallel temperature-compensating fiber Bragg gratings and polytetrafluoroethylene diaphragm waterproof design, and realizes high-precision and high-stability ocean pressure detection.

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

[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 grating assembly mounted inside the rectangular cylindrical shell; a receiving space is formed inside the rectangular cylindrical shell, the upper end of the space is open and the bottom end is provided with a guide hole; the pressure grating assembly comprises: a piston, an H-shaped stainless steel tube, a T-shaped lever, a temperature-compensating fiber Bragg grating, a first pressure grating, and a second pressure grating;

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

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

[0012] The T-shaped lever includes 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 compensating 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] Furthermore, the pressure measuring grating assembly further comprises: a first diaphragm mounted horizontally below the piston, and a second diaphragm mounted 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 cylindrical shell and the H-shaped stainless steel tube, and the two ends of the second diaphragm are respectively fixedly connected to the rectangular cylindrical 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 are output 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 cylindrical 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 are 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 for the lever-type dual fiber Bragg grating pressure sensor, comprising the following steps:

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

[0027] Fiber Bragg grating packaging: A fiber Bragg grating with a central wavelength of 1310 nm is selected, and the temperature compensation fiber Bragg grating is encapsulated inside an H-shaped stainless steel tube. The first pressure measuring fiber Bragg grating and the second pressure measuring fiber Bragg grating are respectively encapsulated in polycarbonate material and symmetrically installed 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 derivation: The two pressure-measuring fiber Bragg gratings are connected in series through the second optical fiber, and the temperature-compensating fiber Bragg grating is connected in parallel with the pressure-measuring fiber Bragg grating through the first optical fiber. These are coupled at the bottom end of the rectangular cylindrical shell to form a derivation optical fiber, which is then derivationed 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 and the response speed is within 30ms, and to verify its stability and accuracy.

[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] The disclosed lever-type dual-fiber Bragg grating pressure sensor significantly improves pressure detection sensitivity by employing dual pressure-measuring fiber Bragg gratings (FBG2 and FBG3) symmetrically arranged above and below a T-shaped lever, combined with a polycarbonate polymer encapsulation. Furthermore, the piston and T-shaped lever design shortens pressure response time to less than 30ms, meeting the requirements for high-precision and rapid response in shallow-water marine pressure detection.

[0034] 2. A temperature-compensating fiber Bragg grating (FBG) is installed inside the H-shaped stainless steel tube and connected in parallel with the pressure-measuring FBG. This effectively eliminates the effects of temperature changes on pressure measurement and improves the accuracy of the detection data. In addition, the design of the polytetrafluoroethylene diaphragm prevents seawater infiltration, further enhancing the stability and reliability of the sensor.

[0035] 3. All components are assembled using elements less than 20mm in size, resulting in a compact structure that is easy to carry and install. By adjusting parameters such as piston thickness and T-lever material and thickness, the sensor's sensitivity and response speed can be flexibly adjusted, making it suitable for shallow water pressure detection within the 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any 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 compensating optical fiber Bragg grating, 9- second optical fiber, 10- first pressure measuring optical fiber Bragg grating, 11- first pressure-sensitive material, 12- second pressure-sensitive optical fiber Bragg grating, 13- second pressure-sensitive material, 14- export optical fiber. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0041] Example 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] The rectangular cylindrical shell 1 has an internal accommodation space, an open upper end and a guide hole at the bottom end; the pressure measuring grating assembly includes: a piston 2, an H-shaped stainless steel tube 4, a T-shaped lever 6, a temperature compensating fiber Bragg grating 8, a first pressure measuring fiber Bragg grating 10, and a second pressure measuring fiber Bragg grating 12;

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

[0045] The H-shaped stainless steel tube 4 is inverted and 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 compensating 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] This lever-type dual-FBG pressure sensor utilizes a symmetrical arrangement of two pressure-measuring FBGs and a polycarbonate package, significantly improving pressure detection sensitivity and response speed (less than 30ms). A built-in temperature-compensating FBG connected in parallel with the pressure-measuring FBG effectively eliminates temperature effects and ensures data accuracy. A PTFE diaphragm prevents seawater infiltration and enhances stability. The overall structure is compact, with a component size of less than 20mm, making it easy to carry and install. It is suitable for pressure detection in shallow waters within the 0-800m range.

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

[0051] The pressure measuring grating assembly in this embodiment further comprises: a first diaphragm 3 mounted horizontally below the piston 2, and a second diaphragm 7 mounted 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 cylindrical 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 cylindrical 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, a first diaphragm 3 is installed horizontally below the piston 2, directly blocking the ingress of seawater. A second diaphragm 7 is installed vertically to the right of the H-shaped stainless steel tube 4, further enhancing the waterproofing effect and preventing seawater from seeping through the gap between the H-shaped stainless steel tube 4 and the T-shaped lever 6. This dual-diaphragm design effectively prevents seawater from infiltrating the sensor, ensuring the stability of the pressure-measuring fiber Bragg grating (FBG) and the accuracy of the detected data.

[0055] Furthermore, both the first diaphragm 3 and the second diaphragm 7 are made of polytetrafluoroethylene (PTFE), which has excellent corrosion resistance, water resistance, and elasticity, making it suitable for marine environments. Their dimensions are rationally designed to ensure the waterproof effect of the diaphragms without affecting 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, which is then led out through a guide hole at the bottom end of the rectangular cylindrical shell 1. By using two independent optical fibers to transmit pressure measurement and temperature compensation data, respectively, the overall performance of the system is effectively improved. One optical fiber is used to connect the dual pressure-measuring fiber Bragg grating (FBG), while the other is used for the temperature-compensating FBG. This ensures the independence and stability of signal transmission, reduces mutual interference, and improves the accuracy and reliability of the 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, with its low Young's modulus and high elasticity, effectively amplifies the strain response of fiber Bragg gratings (FBGs), significantly improving pressure detection sensitivity. By using polycarbonate encapsulation in pressure-measuring FBGs, the sensor can produce greater deformation when subjected to external pressure, thereby enhancing the wavelength shift of the FBG and improving the accuracy of pressure measurements. Furthermore, polycarbonate's excellent corrosion resistance and mechanical strength make it suitable for marine environments, ensuring the stability and reliability of the sensor over long-term use.

[0059] In this embodiment, the rectangular cylindrical 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 are fiber Bragg gratings with a central wavelength of 1310 nm.

[0062] The piston 2 is made of 7075 aluminum alloy, has 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 less than 20mm in size, which makes the entire sensor compact, small in size, light in weight, easy to carry and install. It is particularly suitable for on-site monitoring tasks in complex environments such as the ocean, fully demonstrating its technical advantages of compact structure and portability.

[0064] The lever-type dual fiber Bragg grating pressure sensor in this embodiment achieves high-precision pressure detection through the coordinated operation 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-shaped lever 6 through the H-shaped stainless steel tube 4 welded to it. The upper and lower parts of the short part of the T-shaped lever 6 are respectively tensile and compressive, which drive 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 material, the strain response can be amplified, significantly improving the sensitivity of pressure detection. The deformation causes the effective refractive index of the fiber grating to change, which in turn causes the center wavelength to shift. By detecting the wavelength changes of the first pressure-measuring fiber grating 10 and the second pressure-measuring fiber grating 12 through a demodulation device, the magnitude of the external pressure can be accurately calculated.

[0066] At the same time, the temperature-compensating 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-compensating 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, and are respectively installed horizontally below the piston 2 and vertically on the right side of the h-shaped stainless steel tube 4 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 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] Example 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 are selected and processed into rectangular cylindrical shells, pistons, H-shaped stainless steel tubes, T-shaped levers, and diaphragms based on preset standards;

[0070] Fiber Bragg grating packaging: A fiber Bragg grating with a central wavelength of 1310 nm is selected, and the temperature compensation fiber Bragg grating is encapsulated inside an H-shaped stainless steel tube. The first pressure measuring fiber Bragg grating and the second pressure measuring fiber Bragg grating are respectively encapsulated in polycarbonate material and symmetrically installed 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 derivation: The two pressure-measuring fiber Bragg gratings are connected in series through the second optical fiber, and the temperature-compensating fiber Bragg grating is connected in parallel with the pressure-measuring fiber Bragg grating through the first optical fiber. These are coupled at the bottom end of the rectangular cylindrical shell to form a derivation optical fiber, which is then derivationed 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 and the response speed is within 30ms, and to verify its stability and accuracy.

[0074] This embodiment provides a method for fabricating a lever-type dual-fiber Bragg grating pressure sensor. The sensor utilizes materials such as 304 stainless steel, 7075 aluminum alloy, polytetrafluoroethylene, and polycarbonate, and precisely processes its components, using argon arc welding to ensure a tight and hermetic sensor structure. The fiber Bragg grating packaging and coupling design enhance pressure detection sensitivity and temperature compensation. Finally, testing and calibration using a standard pressure source and temperature control chamber ensures a pressure sensitivity of at least 3.05 nm / MPa and a response speed of less than 30 ms, verifying its stability and accuracy.

[0075] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. References to the same or similar parts between the various embodiments are sufficient. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For relevant parts, refer to the method description.

[0076] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily 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 is not limited to the embodiments shown herein but is intended to conform 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 accommodating 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 Bragg grating (8), a first pressure measuring optical fiber Bragg grating (10) and a second pressure measuring optical fiber Bragg 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 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 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) via 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. The 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) mounted horizontally below the piston (2), and a second diaphragm (7) mounted 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 cylindrical 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 cylindrical 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 2, 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 the 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 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-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 cylindrical 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-compensating fiber Bragg grating (8), the first pressure-measuring fiber Bragg grating (10), and the second pressure-measuring fiber Bragg grating (12) adopt fiber Bragg 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, has a length of 12 mm, a width of 8 mm, and a thickness of 6 mm.

10. A method for preparing a lever-type dual fiber Bragg grating pressure sensor, 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 are selected and processed into 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 the temperature compensation fiber Bragg grating is packaged inside the H-shaped stainless steel tube. The first pressure measuring fiber Bragg grating and the second pressure measuring fiber Bragg grating are respectively packaged in 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 derivation: The two pressure-measuring fiber Bragg gratings are connected in series through the second optical fiber, and the temperature-compensating fiber Bragg grating is connected in parallel with the pressure-measuring fiber Bragg grating through the first optical fiber. These are coupled at the bottom end of the rectangular cylindrical shell to form a derivation optical fiber, which is then derivationed 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 and the response speed is within 30ms, and to verify its stability and accuracy.

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