An integrated fiber optic ocean temperature, salinity and depth multi-parameter sensor based on cumulative fiber optic length sensitization

Abstract

The present invention discloses an optical fiber ocean temperature, salinity, and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization. The sensor is characterized in that it comprises a hatch cover module, a depth measurement module, a temperature module measurement block, and a salinity measurement module, which are sequentially connected by single-mode optical fibers along the direction from signal input to signal output; the hatch cover module comprises a sensor top cover and an optical fiber hatch connector; the depth measurement module comprises an inner protective shell, a depth-sensitive optical fiber ring, a depth transducer disc, and seawater; the temperature measurement module comprises thermal oil, a temperature-sensitive optical fiber ring, and a temperature transducer core shaft; and the salinity measurement module comprises an outer protective shell, an outer hollow structure, a salt-sensitive optical fiber structure, and an inner core shaft structure. The present invention has the beneficial effects of establishing a temperature, salinity, and depth sensing model in which "one optical fiber measures multiple parameters," thereby solving the problems of low versatility, low sampling rate, low integration, and poor long-term stability of temperature, salinity, and depth meters.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber temperature, salinity and depth sensors, and in particular to an optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization. Background Art

[0002] Temperature, salinity, and depth sensors are devices used to understand ocean hydrological characteristics, monitor climate change, and conduct environmental monitoring. Fiber optic sensing technology, due to its inherent advantages such as high sensitivity, large-scale multiplexing, and resistance to electromagnetic interference, has become a highly sought-after emerging technology. Practical engineering applications are placing new demands on the versatility, integration, and electromagnetic interference resistance of temperature, salinity, and depth sensors. While traditional electronic temperature, salinity, and depth sensors are technologically mature, they are expensive, susceptible to seawater corrosion, and lack integration. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies of the existing technology and provide an optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization, which is used to measure the accurate temperature, salinity and depth information of a specific location in the ocean.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: it involves an optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization, including a cabin cover module, a depth measurement module, a temperature measurement module and a salinity measurement module connected in sequence by single-mode optical fiber along the direction from signal input to signal output; the cabin cover module includes a sensor top cover and an optical fiber cabin joint; the depth measurement module includes an inner protective shell, a depth-sensitive optical fiber ring, a depth transducer disc, and seawater; the temperature measurement module includes heat transfer oil, a temperature-sensitive optical fiber ring, and a temperature transducer core shaft; the salinity measurement module includes an outer protective shell, an outer hollow structure, a salt-sensitive optical fiber structure, and an inner core shaft structure.

[0005] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization, the depth measurement module is characterized in that the top of the inner protective shell is provided with an optical fiber through-cabin connector; the depth-sensitive optical fiber ring is bonded to the inner side of the depth transducer disc, and the winding method is multi-turn and multi-layer; the depth-sensitive optical fiber ring is immersed in internally sealed heat-conducting oil, and the seawater temperature can be conducted to the depth-sensitive optical fiber ring; the outer side of the depth transducer disc contacts the seawater, and converts the seawater pressure into the strain change of the optical fiber on the depth-sensitive optical fiber ring.

[0006] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization, the temperature measurement module is characterized in that it is an integral structure with the depth measurement module; the temperature-sensitive optical fiber ring is wound around the outside of the temperature transducer core shaft, and the winding method is multi-turn and multi-layer; the temperature-sensitive optical fiber ring is immersed in the same heat transfer oil environment as the depth-sensitive optical fiber ring, and the two optical fiber rings detect the same seawater temperature information; the temperature transducer core shaft is a columnar structure, and the interior is hollow and in direct contact with seawater, and the seawater temperature is transmitted to the temperature-sensitive optical fiber ring through the temperature transducer core shaft and the heat transfer oil.

[0007] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization, the depth measurement module and the temperature measurement module are characterized in that the inner protective shell covers the overall structure of the temperature measurement module and the depth measurement module, and the top of the inner protective shell includes a first penetration plug and a balance plug, the first penetration plug is used for optical fiber access, and the balance plug is used to prevent thermal oil from overflowing; a cavity is formed between the overall structure and the protective shell, and thermal oil is injected into the cavity to make the internal temperature of the sensor consistent with the seawater temperature.

[0008] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization, the salinity measurement module is characterized in that the front end part of the protective shell, from the inside to the outside structure is a second cabin plug, an inner core shaft structure, a salt-sensitive optical fiber structure, and an outer hollow structure.

[0009] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitivity enhancement is characterized in that the salt-sensitive optical fiber structure uses polyimide (PI) material to be layered coated on an optical fiber ring, the optical fiber ring is wrapped around the outside of the inner core shaft structure, and the optical fiber ring is wound in multiple turns and multiple layers.

[0010] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization is characterized in that the depth-sensitive optical fiber ring, the temperature-sensitive optical fiber ring and the optical fiber rings in the salt-sensitive optical fiber structure are connected in series in sequence through a single-mode optical fiber, and the access optical fiber enters from the optical fiber through-cabin connector and is connected out by the salt-sensitive optical fiber structure; the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor is connected in series to form a sensing array, and the distributed optical fiber strain demodulation equipment can be used to demodulate the ocean multi-point temperature, salinity and depth information.

[0011] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization is characterized in that multiple parameters are referenced and compensated for each other, the signal measured by the depth measurement module needs to strip off the temperature information to obtain accurate depth information, and the signal measured by the salinity measurement module needs to strip off the accurate glass temperature and depth information to obtain accurate salinity information.

[0012] The beneficial effects of the present invention are as follows: providing a novel ocean temperature, salinity and depth measurement method, using one optical fiber to connect a depth measurement module, a temperature measurement module and a salinity measurement module in series in sequence to form an optical fiber ocean temperature, salinity and depth integrated sensor; utilizing the length accumulation effect of low-loss optical fiber to achieve enhanced sensitivity measurement of depth, temperature and salinity signals; the present invention immerses both temperature and depth sensing optical fibers in a thermal oil environment, so that the temperature interference of the two is substantially the same, so that the temperature sensor can be used as a reference sensor for depth measurement, and accurate depth information can be obtained by stripping away temperature interference; similarly, the salinity sensor can strip away temperature and depth interference to obtain accurate salinity information; multiple optical fiber ocean temperature, salinity and depth integrated sensors can be connected in series to form a sensor array, and temperature, salinity and depth information at different locations in the ocean can be synchronously collected; the "one fiber, multiple measurements" temperature, salinity and depth sensing integrated model solves the problems of low versatility, low sampling rate, low integration and poor long-term stability of temperature, salinity and depth meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of a specific embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the principle structure of the cabin cover module in the temperature, salinity and depth sensor in this embodiment.

[0015] Figure 3 This is a schematic diagram of the principle structure of the temperature and depth measurement module in the temperature-salinity-depth sensor in this embodiment.

[0016] Figure 4 This is a schematic diagram of the principle structure of the salinity measurement module in the temperature, salinity and depth sensor in this embodiment.

[0017] Among them: 1. Cabin cover; 2. Depth measurement module; 3. Temperature measurement module; 4. Salinity measurement module; 5. Single-mode optical fiber; 6. Sensor top cover; 7. Optical fiber cabin joint; 8. Temperature transducer core shaft; 9. Depth transducer disc; 10. Depth-sensitive optical fiber ring; 11. Inner protective shell; 12. First cabin plug; 13. Balance plug; 14. Thermal oil; 15. Seawater; 16. Temperature-sensitive optical fiber ring; 17. Outer hollow structure; 18. Second cabin plug; 19. Outer protective shell; 20. Inner core shaft structure; 21. Salt-sensitive optical fiber structure. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization shown includes a cabin cover 1, a depth measurement module 2, a temperature measurement module 3 and a salinity measurement module 4, which are connected in sequence through a single-mode optical fiber 5 along the direction from signal input to signal output; the cabin cover module 1 includes a sensor top cover 6 and an optical fiber cabin joint 7; the depth measurement module 2 includes an inner protective shell 11, a depth-sensitive optical fiber ring 10, a depth transducer disc 9, and seawater 15; the temperature measurement module 3 includes heat transfer oil 14, a temperature-sensitive optical fiber ring 16, and a temperature transducer core shaft 8; the salinity measurement module 4 includes an outer protective shell 19, an outer hollow structure 17, a salt-sensitive optical fiber structure 21, and an inner core shaft structure 20.

[0020] Preferably, the top of the inner protective shell 11 is provided with a fiber optic penetration connector 7; the deep-sensitive fiber optic ring 10 is bonded to the inner side of the depth transducer disc 9, and is wound in multiple turns and multiple layers; the deep-sensitive fiber optic ring 10 is immersed in the internally sealed heat transfer oil 14, and the seawater temperature can be conducted to the deep-sensitive fiber optic ring 10; the outer side of the depth transducer disc 9 contacts the seawater 15, converting the seawater pressure into the strain change of the optical fiber on the deep-sensitive fiber optic ring 10.

[0021] Preferably, the temperature measurement module 3 and the depth measurement module 2 are an integral structure; the temperature-sensitive optical fiber ring 16 is wound around the outside of the temperature transducer core shaft 8, and the winding method is multiple turns and multiple layers; the temperature-sensitive optical fiber ring 16 is immersed in the same heat transfer oil 14 environment as the depth-sensitive optical fiber ring 10, and the two optical fiber rings detect the same seawater temperature information; the temperature transducer core shaft 8 is a columnar structure, and the interior is hollow and in direct contact with the seawater 15, and the seawater temperature is transmitted to the temperature-sensitive optical fiber ring 16 through the temperature transducer core shaft 8 and the heat transfer oil 14.

[0022] Preferably, the inner protective shell 11 covers the overall structure of the temperature measurement module 3 and the depth measurement module 2. The top of the inner protective shell 11 includes a first optical fiber penetration plug 12 and a balancing plug 13. The first penetration plug 12 is used for optical fiber access, and the balancing plug 13 is used to prevent the thermal oil 14 from overflowing. A cavity is formed between the overall structure and the inner protective shell 11, and the thermal oil 14 is injected into the cavity to make the internal temperature of the sensor consistent with the seawater temperature.

[0023] Preferably, the front end portion of the outer protective shell 19 comprises, from inside to outside, an inner core shaft structure 20 , a salt-sensitive optical fiber structure 21 , and an outer hollow structure 17 .

[0024] Preferably, the salt-sensitive optical fiber structure 21 is coated with polyimide (PI) material in layers on an optical fiber ring, and the optical fiber ring is wound around the outside of the inner core shaft structure, and the optical fiber ring is wound in multiple turns and multiple layers.

[0025] Preferably, the fiber optic rings in the depth-sensitive fiber optic ring 10, the temperature-sensitive fiber optic ring 16 and the salt-sensitive fiber optic structure 21 are connected in series in sequence through a single-mode optical fiber 5, and the access optical fiber enters from the optical fiber through-cabin connector 7 and is connected out by the salt-sensitive optical fiber structure 21; the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor can be connected in series to form a sensing array, and the distributed optical fiber strain demodulation equipment can be used to demodulate the ocean multi-point temperature, salinity and depth information.

[0026] Preferably, multiple parameters are referenced and compensated with each other. The signal measured by the depth measurement module 2 needs to be stripped of temperature information to obtain accurate depth information. The signal measured by the salinity measurement module 4 needs to be stripped of accurate glass temperature and depth information to obtain accurate salinity information.

[0027] The above embodiments are intended only to illustrate the design concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The scope of protection of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design concepts disclosed in the present invention are within the scope of protection of the present invention.

Claims

1. An optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization, characterized in that: It includes a cabin cover module, a depth measurement module, a temperature measurement module and a salinity measurement module, which are connected in sequence through single-mode optical fiber along the direction from signal input to signal output; the cabin cover module includes a sensor top cover and an optical fiber cabin joint; the depth measurement module includes an inner protective shell, a depth-sensitive optical fiber ring, a depth transducer disc, and seawater; the temperature measurement module includes heat-conducting oil, a temperature-sensitive optical fiber ring, and a temperature transducer core shaft; the salinity measurement module includes an outer protective shell, an outer hollow structure, a salt-sensitive optical fiber structure, and an inner core shaft structure.

2. The optical fiber ocean temperature, salinity, depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization according to claim 1, wherein the depth measurement module is characterized in that: The top of the inner protective shell is provided with an optical fiber penetration joint; the depth-sensitive optical fiber ring is bonded to the inner side of the depth transducer disc, and is wound in multiple turns and multiple layers; the depth-sensitive optical fiber ring is immersed in internally sealed heat-conducting oil, and the seawater temperature can be conducted to the depth-sensitive optical fiber ring; the outer side of the depth transducer disc contacts the seawater, converting the seawater pressure into strain changes of the optical fiber on the depth-sensitive optical fiber ring.

3. According to the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization according to claim 1, the temperature measurement module is characterized in that: It forms an integral structure with the depth measurement module; the temperature-sensitive optical fiber ring is wound around the outside of the temperature transducer core shaft in a multi-turn and multi-layer manner; the temperature-sensitive optical fiber ring is immersed in the same heat transfer oil environment as the depth-sensitive optical fiber ring, and the two optical fiber rings detect the same seawater temperature information; the temperature transducer core shaft is a columnar structure, and the interior is hollow and in direct contact with the seawater, and the seawater temperature is transmitted to the temperature-sensitive optical fiber ring through the temperature transducer core shaft and the heat transfer oil.

4. The optical fiber ocean temperature, salinity, depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization according to claim 1, wherein the temperature measurement module and the depth measurement module are characterized in that: The inner protective shell covers the overall structure of the temperature measurement module and the depth measurement module. The top of the inner protective shell includes a first penetration plug and a balancing plug. The first penetration plug is used for optical fiber access, and the balancing plug is used to prevent thermal oil from overflowing. A cavity is formed between the overall structure and the protective shell, and thermal oil is injected into the cavity to make the internal temperature of the sensor consistent with the seawater temperature.

5. The optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization according to claim 1, wherein the salinity measurement module is characterized in that: The front end portion of the protective shell comprises, from inside to outside, a second penetration plug, an inner core shaft structure, a salt-sensitive optical fiber structure, and an outer hollow structure.

6. The optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitivity enhancement according to claim 5, wherein the salt-sensitive optical fiber structure is characterized in that: The salt-sensitive optical fiber structure uses polyimide (PI) material to be layered coated on an optical fiber ring. The optical fiber ring is wound around the outside of the inner core shaft structure, and the optical fiber ring is wound in a multi-turn and multi-layer manner.

7. The optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization according to claim 1, characterized in that: The optical fiber rings in the depth-sensitive optical fiber ring, temperature-sensitive optical fiber ring and salt-sensitive optical fiber structure are connected in series in sequence through a single-mode optical fiber. The access optical fiber enters from the optical fiber through-cabin connector and is connected out by the salt-sensitive optical fiber structure. The optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor is connected in series to form a sensing array, and the distributed optical fiber strain demodulation equipment can be used to demodulate the ocean multi-point temperature, salinity and depth information.

8. The optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization according to claim 1, characterized in that: For the mutual reference compensation among multiple parameters, the signal measured by the depth measurement module needs to be stripped of the temperature information to obtain accurate depth information, and the signal measured by the salinity measurement module needs to be stripped of the accurate glass temperature and depth information to obtain accurate salinity information.

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