CN115014229A - High-voltage-resistant optical fiber Fabry-Perot sensor - Google Patents
High-voltage-resistant optical fiber Fabry-Perot sensor Download PDFInfo
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- CN115014229A CN115014229A CN202210708200.7A CN202210708200A CN115014229A CN 115014229 A CN115014229 A CN 115014229A CN 202210708200 A CN202210708200 A CN 202210708200A CN 115014229 A CN115014229 A CN 115014229A
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- fabry
- perot
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
- G01B11/18—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge using photoelastic elements
Abstract
The invention discloses a high-pressure-resistant optical fiber Fabry-Perot sensor which is characterized by comprising a cylindrical protective tube body and optical fiber Fabry-Perot sensing assemblies arranged in the protective tube body along the length direction, wherein end cover assemblies are arranged at two ends of the protective tube body in a sealing mode, each optical fiber Fabry-Perot sensing assembly comprises a sensing optical fiber which penetrates through one end cover assembly along the axial direction and a tail optical fiber which is installed at the inner end of the other end cover assembly, a sleeve pipe is coaxially sleeved at one end, opposite to the sensing optical fiber, of the tail optical fiber, and a Fabry-Perot cavity structure is formed between the two ends. The invention has the advantages of strong bearing capacity, difficult damage, long service life and the like.
Description
Technical Field
The invention relates to the technical field of optical fiber sensing, in particular to a high-voltage-resistant optical fiber Fabry-Perot sensor.
Background
Optical fiber sensing is one of the important applications of modern optical fiber technology, has the advantages of small volume, simple structure, high sensitivity, strong anti-electromagnetic interference capability, long-distance transmission and the like, and can be used for detecting various physical quantities, such as strain, temperature, pressure, sound field, electric field, vibration, acceleration and the like. The optical fiber Fabry-Perot sensor is one of the sensors, and is widely applied to real-time health detection of large engineering structures such as bridges, balance structures, petroleum pipelines and the like. An optical fiber Fabry-Perot strain sensor generally encapsulates an optical fiber and a Fabry-Perot cavity on a strain foil which is easy to deform, and when the optical fiber Fabry-Perot strain sensor is used, the strain foil is installed on a structure to be measured, the deformation of the structure to be measured causes the deformation of the strain foil, and finally a measurement result is obtained.
When the Fabry-Perot optical fiber strain sensor is used, the Fabry-Perot optical fiber strain sensor is often applied to a high-temperature and high-pressure environment, the pressure reaches 17.5MPa, the existing Fabry-Perot optical fiber strain sensor cannot bear the external pressure, the sensor is damaged, and the detection purpose cannot be achieved.
Disclosure of Invention
Aiming at the defects of the prior art, the technical problems to be solved by the invention are as follows: how to provide a bearing capacity reinforce, not fragile is favorable to increase of service life's optic fibre fabry-perot sensor.
In order to solve the technical problems, the invention adopts the following technical scheme:
the utility model provides a high pressure resistant optic fibre Fabry-Perot sensor, its characterized in that is in including being cylindric protection body and along length direction setting optic fibre Fabry-Perot sensing component in the protection body, the both ends of protection body are provided with the end cover subassembly with sealing, optic fibre Fabry-Perot sensing component includes that the sensing optic fibre that passes one of them end cover subassembly along the axial with install the inner tail optical fiber at another end cover subassembly, the coaxial cover of one end that sensing optic fibre and tail optical fiber are relative is equipped with the sleeve pipe, and forms Fabry-Perot cavity structure between the two.
During the use, will protect the both ends of body to fix respectively on the object's that awaits measuring the surface, in case the surface of the object that awaits measuring takes place deformation, will change the length of protection body, and then let the Fabry-Perot chamber length between sensing optical fiber and the tail-fiber change, realize the measurement to meeting an emergency. Because the protection body is cylindricly, when measuring in the fluid, the fluid is exerted on the radial effect of protection body along the protection body at the pressure on protection body surface, because the same pressure forms the balance each other along circumference equipartition to can avoid the protection body to take place to warp and damage in footpath, the bearing capacity is strong, is favorable to forming the protection to inside optic fibre Fabry-Perot sensing subassembly, avoids damaging, has prolonged the life of sensor.
Furthermore, the protective tube body is made of a metal capillary tube.
Furthermore, the surface of the protection pipe body is provided with a weakening groove arranged along the circumferential direction, the weakening groove is spiral or annular, and the maximum depth of the weakening groove is smaller than the minimum thickness of the protection pipe body.
Therefore, the pressure borne by the surface of the protective pipe body can be ensured to be balanced in the circumferential direction, and the strength of the protective pipe body in the axial direction can be reduced, so that the deformation of the surface of an object to be detected can be reliably transmitted to the protective pipe body, and the sensing precision is ensured.
Furthermore, the weakening groove is formed by laser, electric spark or corrosion processing.
Furthermore, the outer diameter of the protective pipe body is 2 mm-5 mm, and the wall thickness is 0.1-0.2 mm.
Furthermore, the end cover assembly comprises a long strip-shaped base and a cylindrical end cover, the end cover is connected to the base along the width direction of the base, and one end of the end cover is provided with a circular groove or a boss for plugging the protection pipe body.
Further, the distance between the bottom of the base and the axis of the end cover is greater than the radius of the protective pipe body.
Like this, when will protect the body through the base and fix on the object surface that awaits measuring, can guarantee to have the clearance between protection body and the object surface, let the fluid can fully surround the protection body, avoid being used in the pressure unbalance on the protection body and cause protection body pressurized damage.
Furthermore, a rectangular sheet-shaped strain gauge is connected between the two end cover assemblies, the strain gauge comprises a pigtail substrate, an Fabry-Perot cavity substrate and a sensing optical fiber substrate which are sequentially arranged at intervals along the length direction, annular elastic deformation rings are connected between the pigtail substrate and the Fabry-Perot cavity substrate and between the Fabry-Perot cavity substrate and the sensing optical fiber substrate, and each elastic deformation ring comprises two arc-shaped semi-rings symmetrically arranged along the width direction of the strain gauge; the sensing optical fiber, the tail optical fiber and the sleeve are respectively fixed on the sensing optical fiber substrate, the tail optical fiber substrate and the Fabry-Perot cavity substrate.
Furthermore, the strain gauge is provided with an optical fiber groove extending along the axial direction of the protective tube body, and the sensing optical fiber, the tail fiber and the sleeve are respectively fixed in the optical fiber grooves of the sensing optical fiber substrate, the tail fiber substrate and the Fabry-Perot cavity substrate.
Furthermore, the pigtail substrate, the Fabry-Perot cavity substrate and the sensing optical fiber substrate are respectively provided with a glue dripping groove communicated with the optical fiber grooves, and the pigtail, the sleeve and the sensing optical fiber are fixed in the corresponding optical fiber grooves through viscose glue; silica gel is filled at two ends of the sleeve.
In conclusion, the bearing device has the advantages of being strong in bearing capacity, not prone to damage, beneficial to prolonging service life and the like.
Drawings
Fig. 1 is a schematic overall structure diagram of the present embodiment.
FIG. 2 is a schematic structural view of an end cap assembly.
Fig. 3 is a schematic structural view of the protective tube.
Fig. 4 and 5 are schematic structural views of the strain gauge.
Detailed Description
The present invention will be described in further detail with reference to examples.
In the specific implementation: as shown in fig. 1 to 5, the high-voltage-resistant optical fiber fabry-perot sensor includes a cylindrical protection tube 1 and an optical fiber fabry-perot sensing module 2 disposed in the protection tube 1 along a length direction, wherein end cap modules 3 are disposed at two ends of the protection tube 1 in a sealing manner, and a rectangular sheet-shaped strain gauge 4 is connected between the two end cap modules 3.
During the use, will protect the both ends of body to fix respectively on the object's that awaits measuring the surface, in case the surface of the object that awaits measuring takes place deformation, will change the length of protection body, and then let the Fabry-Perot chamber length between sensing optical fiber and the tail-fiber change, realize the measurement to meeting an emergency. Because the protection body is cylindricly, when measuring in the fluid, the fluid is exerted on the radial effect on the protection body along the protection body at the pressure on protection body surface, because the same pressure forms the balance each other along circumference equipartition to can avoid the protection body to take place deformation and damage in footpath, the bearing capacity is strong, is favorable to forming the protection to inside optic fibre fabry-perot sensing element, avoids damaging, has prolonged the life of sensor.
The optical fiber Fabry-Perot sensing assembly 2 comprises a sensing optical fiber 21, a tail optical fiber 22 and a sleeve 23 which are coaxially arranged, one opposite ends of the sensing optical fiber 21 and the tail optical fiber 22 extend into the sleeve 23 to form a Fabry-Perot cavity structure, the sensing optical fiber 21 penetrates through one end cover assembly 3, the tail optical fiber 22 is arranged at the inner end of the other end cover assembly 3, and two ends of the sleeve 23 are filled with sealing silica gel. The sealing silica gel is used for ensuring the original cavity length of the Fabry-Perot cavity between the sensing optical fiber 21 and the tail optical fiber 22, and during detection, the sensing optical fiber 21 and the tail optical fiber 22 move relatively under the action of external force to change the cavity length of the Fabry-Perot cavity, so that optical signals in the sensing optical fiber 21 are changed, and the strain can be measured. Once the external deformation is eliminated, the sealing silica gel can also enable the Fabry-Perot cavity between the two to be recovered to the original cavity length.
As shown in fig. 4, the strain gauge 4 includes a pigtail substrate 41, an amber cavity substrate 42 and a sensing fiber substrate 43 sequentially arranged at intervals along a length direction, annular elastic deformation rings 44 are connected between the pigtail substrate 41 and the amber cavity substrate 42 and between the amber cavity substrate 42 and the sensing fiber substrate 43, and each elastic deformation ring 44 includes two arc semi-rings symmetrically arranged along a width direction of the strain gauge 4; the strain gauge 4 is provided with an optical fiber groove extending along the axial direction of the protective tube body 1, and the sensing optical fiber 21, the tail fiber 22 and the sleeve 23 are respectively fixed in the optical fiber grooves of the sensing optical fiber substrate 43, the tail fiber substrate 41 and the Fabry-Perot cavity substrate 42.
Specifically, the pigtail substrate 41, the Fabry-Perot cavity substrate 42 and the sensing optical fiber substrate 43 are respectively provided with a glue dripping groove communicated with the optical fiber grooves, and the pigtail, the sleeve and the sensing optical fiber are fixed in the corresponding optical fiber grooves through viscose glue.
Thus, the tail fiber and the sensing optical fiber are respectively fixed on the tail fiber substrate and the sensing optical fiber substrate through viscose glue, the sleeve is fixed on the Fabry-Perot cavity substrate 42, and the opposite ends of the tail fiber and the sensing optical fiber extend into the sleeve to be free ends. After the end cover assemblies 3 at two ends are stressed, the tail fiber substrate 41 and the sensing optical fiber substrate 43 move relative to the Fabry-Perot cavity substrate 42, the tail fiber and the sensing optical fiber are pulled, the cavity length of a Fabry-Perot cavity between the tail fiber and the sensing optical fiber is changed, and therefore detection is achieved. The pigtail substrate 41 and the sensing optical fiber substrate 43 move relative to the Fabry-Perot cavity substrate 42, and the elastic deformation ring 44 is elastically deformed, so that once the external force is eliminated, the elastic deformation ring can reset the pigtail and the sensing optical fiber.
The end cap assembly 3 includes an elongated base 31 and a cylindrical end cap 32, the end cap 32 is connected to the base 31 along the width direction of the base 31, and one end of the end cap 32 has a circular groove or a boss for plugging the protective tube 1. The distance between the bottom of the base 31 and the axis of the end cap 32 is greater than the radius of the protective tube 1.
Like this, when will protect the body through the base and fix on the object surface that awaits measuring, can guarantee to have the clearance between protection body and the object surface, let the fluid can fully surround the protection body, avoid being used in the pressure unbalance on the protection body and cause protection body pressurized damage.
In this embodiment, the both ends of foil gage 4 are connected with cylindric base, the diameter of base and the internal diameter phase-match of protection body 1, the both ends of protection cover pipe 1 cup joint on the base.
The base 31 and the end cover 32 are integrally formed, one side of the end cover 32 is provided with a circular groove, and the inner diameter of the circular groove is consistent with the diameter of the base and is sleeved on the base. The bottom of the base 31 has two positioning holes, which are distributed along the length direction of the base 31. Therefore, when the calibration is carried out, the corresponding positioning holes can be arranged at the corresponding positions on the measured standard body, and the optical fiber Fabry-Perot sensor to be calibrated is connected with the measured standard body by the plug pin, so that the calibration efficiency is improved.
In addition, in this embodiment, the protection sleeve 1 is filled with high-temperature-resistant soft glue. Therefore, the high-temperature-resistant soft rubber is used for wrapping the part of the middle strain ring (the elastic deformation ring 44) and wrapping the suspended optical fiber of the strain ring part, so that the suspended optical fiber is prevented from being shattered under the action of external vibration, and the shockproof effect is achieved. The high-temperature-resistant soft rubber is a mature existing product, the high-temperature-resistant soft rubber product is vulcanized into an elastomer by contacting with moisture in the air, the vulcanized rubber can be used for a long time in a temperature range of-60 to +2000 ℃, and has excellent electrical insulating property and chemical stability, water resistance, ozone resistance, weather aging resistance and good adhesion to various metal and non-metal materials.
In addition, the inner cavity of the protective sleeve 1 is filled with the high-temperature-resistant soft glue, certain support is formed on the protective sleeve from the inside, and meanwhile, once the protective sleeve is damaged, the strain gauge 4 and the optical fiber Fabry-Perot sensing assembly 2 installed on the strain gauge can be completely wrapped by the high-temperature-resistant soft glue to form protection, so that the optical fiber Fabry-Perot sensing assembly 2 is prevented from being damaged by high pressure, and the use reliability of the sensor is improved.
In this embodiment, the protection tube body 1 is made of a stainless steel capillary tube (or made of other metal capillary tubes), and in view of the fact that after the protection tube body 1 is added, the overall deformation capacity of the sensor in the axial direction is weakened, in order to ensure sufficient detection accuracy, in this embodiment, the surface of the protection tube body 1 is provided with a weakening groove (as shown in fig. 3) which is arranged along the circumferential direction, the weakening groove is spiral or annular, and the maximum depth of the weakening groove is smaller than the minimum thickness of the protection tube body 1.
Therefore, the pressure borne by the surface of the protective pipe body can be ensured to be balanced in the circumferential direction, and the strength of the protective pipe body in the axial direction can be reduced, so that the deformation of the surface of an object to be detected can be reliably transmitted to the protective pipe body, and the sensing precision is ensured.
In this embodiment, the outer diameter of the protective tube body 1 is 2.5mm, and the wall thickness is 0.1mm, and since the wall thickness of the protective tube body 1 is very thin, the weakening groove can be formed by laser, electric spark or corrosion processing.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention, which is intended to cover any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention.
Claims (10)
1. The utility model provides a high pressure resistant optic fibre fabry-perot sensor, its characterized in that is in including being cylindric protection body (1) and setting up along length direction optic fibre fabry-perot sensing element (2) in the protection body (1), the both ends of protection body (1) are provided with end cover subassembly (3) with sealing, optic fibre fabry-perot sensing element (2) include along sensing optic fibre (21) that the axial passed one of them end cover subassembly (3) and install tail optical fiber (22) in another end cover subassembly (3) inner, the coaxial cover of one end that sensing optic fibre (21) and tail optical fiber (22) are relative is equipped with sleeve pipe (23), and forms fabry-perot cavity structure between the two.
2. The high-voltage-resistant fiber Fabry-Perot sensor according to claim 1, characterized in that the protective tube body (1) is made of a metal capillary tube.
3. The high-voltage-resistant fiber Fabry-Perot sensor according to claim 1 or 2, characterized in that the surface of the protection tube body (1) is provided with a weakening groove arranged along the circumferential direction, the weakening groove is spiral or circular, and the maximum depth of the weakening groove is smaller than the minimum thickness of the protection tube body (1).
4. The high pressure resistant fiber Fabry-Perot sensor of claim 3, wherein the weakening tank is made using laser, spark or corrosion machining.
5. The high-voltage-resistant fiber Fabry-Perot sensor according to claim 1, wherein the protective tube body (1) has an outer diameter of 2mm to 5mm and a wall thickness of 0.1mm to 0.2 mm.
6. The high-pressure-resistant fiber Fabry-Perot sensor according to claim 1, characterized in that the end cap assembly (3) comprises an elongated base (31) and a cylindrical end cap (32), the end cap (32) is connected to the base (31) along the width direction of the base (31), and one end of the end cap (32) has a circular groove or a boss for plugging the protection tube body (1).
7. The high-pressure-resistant fiber Fabry-Perot sensor according to claim 6, characterized in that the distance between the bottom of the base (31) and the axial center of the end cap (32) is larger than the radius of the protection tube body (1).
8. The high-pressure-resistant fiber Fabry-Perot sensor according to claim 1, wherein a strain gauge (4) in a rectangular sheet shape is connected between the two end cap assemblies (3), the strain gauge (4) comprises a pigtail substrate (41), a Fabry-Perot cavity substrate (42) and a sensing fiber substrate (43) which are sequentially arranged at intervals along the length direction, annular elastic deformation rings (44) are connected between the pigtail substrate (41) and the Fabry-Perot cavity substrate (42) and between the Fabry-Perot cavity substrate (42) and the sensing fiber substrate (43), and the elastic deformation rings (44) comprise two arc semi-rings symmetrically arranged along the width direction of the strain gauge (4); the sensing optical fiber (21), the tail fiber (22) and the sleeve (23) are respectively fixed on the sensing optical fiber substrate (43), the tail fiber substrate (41) and the Fabry-Perot cavity substrate (42).
9. The high-voltage-resistant fiber Fabry-Perot sensor according to claim 8, wherein the strain gauge (1) is provided with fiber grooves extending along the axial direction of the protective tube body (1), and the sensing fiber (21), the pigtail (22) and the sleeve (23) are respectively fixed in the fiber grooves of the sensing fiber substrate (43), the pigtail substrate (41) and the Fabry-Perot cavity substrate (42).
10. The high-pressure-resistant fiber Fabry-Perot sensor according to claim 9, wherein the pigtail substrate (41), the Fabry-Perot cavity substrate (42) and the sensing fiber substrate (43) are respectively provided with a glue dripping groove communicated with the fiber grooves, and the pigtail, the sleeve and the sensing fiber are fixed in the corresponding fiber grooves through glue; and silica gel is filled at two ends of the sleeve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210708200.7A CN115014229A (en) | 2022-06-22 | 2022-06-22 | High-voltage-resistant optical fiber Fabry-Perot sensor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210708200.7A CN115014229A (en) | 2022-06-22 | 2022-06-22 | High-voltage-resistant optical fiber Fabry-Perot sensor |
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| Publication Number | Publication Date |
|---|---|
| CN115014229A true CN115014229A (en) | 2022-09-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210708200.7A Pending CN115014229A (en) | 2022-06-22 | 2022-06-22 | High-voltage-resistant optical fiber Fabry-Perot sensor |
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| CN (1) | CN115014229A (en) |
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- 2022-06-22 CN CN202210708200.7A patent/CN115014229A/en active Pending
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