Optical fiber ocean temperature-salinity-depth multi-parameter integrated sensor based on accumulated optical fiber length sensitization

Abstract

The invention discloses an optical fiber ocean temperature-salinity-depth multi-parameter integrated sensor based on accumulated optical fiber length sensitization, which is characterized by comprising a cabin cover penetrating module, a depth measurement module, a temperature mode measurement block and a salinity measurement module which are sequentially connected through single-mode optical fibers along the direction from signal input to signal output, the cabin penetrating cover body module comprises a sensor top cover and an optical fiber cabin penetrating joint; the depth measurement module comprises an inner layer protection shell, a deep sensitive optical fiber ring, a depth transduction disc and seawater; the temperature measurement module comprises heat conduction oil, a temperature-sensitive optical fiber ring and a temperature transduction mandrel; the salinity measurement module comprises an outer-layer protective shell, an outer-layer hollow structure, a salt-sensitive optical fiber structure and an inner-layer mandrel structure. The temperature-salinity-depth sensor has the beneficial effects that a temperature-salinity-depth sensing model in which a plurality of parameters are measured by one optical fiber is established, and the problems of low universality, low sampling rate, low integration, poor long-term stability and the like of a temperature-salinity-depth instrument are solved.

Description

Technical Field

[0001] The 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 the hydrological characteristics of the ocean, monitor climate change and conduct environmental monitoring. Among them, fiber optic sensing technology has become a new means of concern due to its inherent advantages such as high sensitivity, large-scale multiplexing and anti-electromagnetic interference. In actual engineering applications, new requirements have been put forward for the versatility, integration and anti-electromagnetic interference performance of temperature, salinity and depth instruments. Although traditional electronic temperature, salinity and depth instruments are mature in technology, they are expensive, easily corroded by seawater, and have a low degree of integration. Summary of the invention

[0003] The purpose of the present invention is to provide an optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization to address the deficiencies of the prior art, so as 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-mentioned 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 module measurement block 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 disk, 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 depth measurement module is characterized in that a fiber optic joint is provided on the top of the inner protective shell; the depth-sensitive fiber optic ring is bonded to the inner side of the depth transducer disc, and is wound in multiple turns and multiple layers; the depth-sensitive fiber optic ring is immersed in internally sealed heat transfer oil, and the seawater temperature can be conducted to the depth-sensitive fiber optic ring; the outer side of the depth transducer disc contacts the seawater, and converts the seawater pressure into strain changes of the optical fiber on the depth-sensitive fiber optic ring.

[0006] According to the above scheme, 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 multiple turns and multiple layers; 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.

[0007] According to the above scheme, 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 fiber optic penetration plug and a balancing plug, the 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.

[0008] According to the above scheme, the salinity measurement module is characterized in that the front end portion of the protective shell has an inner core shaft structure, a salt-sensitive optical fiber structure, and an outer hollow structure from the inside to the outside.

[0009] According to the above scheme, 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 the 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 multiple turns and multiple layers.

[0010] According to the above scheme, the optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor is characterized in that the depth-sensitive optical fiber ring, the temperature-sensitive optical fiber ring and the optical fiber ring 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 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 can form a sensor array by serial connection, 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 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. 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: a novel ocean temperature, salinity and depth measurement method is provided, a depth measurement module, a temperature measurement module and a salinity measurement module can be connected in series in sequence by using one optical fiber to form an optical fiber ocean temperature, salinity and depth integrated sensor; the length accumulation effect of low-loss optical fiber is used to realize the enhanced measurement of depth, temperature and salinity signals; the temperature and depth sensing optical fibers are immersed in a heat transfer oil environment, and the temperature interference of the two is basically 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 off the temperature disturbance; similarly, the salinity sensor can strip off the temperature and depth interference to obtain accurate salinity information; a plurality of optical fiber ocean temperature, salinity and depth integrated sensors can form a sensor array by using optical fibers in series to synchronously collect temperature, salinity and depth information at different positions in the ocean; the "one fiber, multiple quantities" 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 instruments. 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 Schematic diagram of the principle structure of the cabin cover module in the temperature-salinity-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 Schematic diagram of the principle structure of the salinity measurement module in the temperature-salinity-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. Cabin plug; 13. Balance plug; 14. Heat transfer oil; 15. Seawater; 16. Temperature-sensitive optical fiber ring; 17. Outer hollow structure; 18. 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 solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 used to limit the present invention.

[0019] like Figure 1 , Figure 2 , Figure 3and Figure 4 An optical fiber ocean temperature, salinity, depth multi-parameter integrated sensor based on cumulative optical fiber length sensitization is shown, comprising a cabin cover module 1, a depth measurement module 2, a temperature module measurement block 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 comprises a sensor top cover 6 and an optical fiber cabin joint 7; the depth measurement module 2 comprises 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 comprises heat transfer oil 14, a temperature-sensitive optical fiber ring 16, and a temperature transducer core shaft 8; the salinity measurement module 4 comprises 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 joint 7; the depth-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 depth-sensitive fiber optic ring 10 is immersed in an internally sealed heat transfer oil 14, and the seawater temperature can be conducted to the depth-sensitive fiber optic ring 10; the outer side of the depth transducer disc 9 contacts the seawater 15, and converts the seawater pressure into the strain change of the optical fiber on the depth-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 fiber optic penetration plug 12 and a balance plug 13. The penetration plug 12 is used for fiber optic access, and the balance plug 13 is used to prevent the heat transfer oil 14 from overflowing. A cavity is formed between the overall structure and the inner protective shell 11, and the heat transfer 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 depth-sensitive optical fiber ring 10, the temperature-sensitive optical fiber ring 16 and the optical fiber rings in the salt-sensitive optical fiber 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 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, and 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 only used to illustrate the design ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design ideas disclosed by the present invention are within the protection scope 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 module measurement block and a salinity measurement module, which are connected in sequence through a 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 depth measurement module according to claim 1, characterized in that: The top of the inner protective shell is provided with a fiber optic cabin joint; the depth-sensitive fiber optic ring is bonded to the inner side of the depth transducer disc and is wound in multiple turns and multiple layers; the depth-sensitive fiber optic ring is immersed in internally sealed heat transfer oil, and the seawater temperature can be conducted to the depth-sensitive fiber optic ring; the outer side of the depth transducer disc contacts the seawater and converts the seawater pressure into strain changes of the optical fiber on the depth-sensitive fiber optic ring.

3. The temperature measurement module according to claim 1, 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 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 depth measurement module and the temperature measurement module according to claim 1, 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 an optical fiber penetration plug and a balancing plug. The 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 salinity measurement module according to claim 1, characterized in that: The front end portion of the protective shell has an inner core shaft structure, a salt-sensitive optical fiber structure, and an outer hollow structure from the inside to the outside.

6. The salt-sensitive optical fiber structure according to claim 5, characterized in that: The salt-sensitive optical fiber structure uses polyimide (PI) material to be layered coated on an optical fiber ring, and the optical fiber ring is wound around the outside of an 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, depth and multi-parameter integrated sensor according to claim 1 is characterized in that: The optical fiber rings in the depth-sensitive optical fiber ring, the temperature-sensitive optical fiber ring and the salt-sensitive optical fiber structure are sequentially connected in series through a single-mode optical fiber, and the access optical fiber enters from the optical fiber cabin joint and is connected from the salt-sensitive optical fiber structure; The optical fiber ocean temperature, salinity and depth multi-parameter integrated sensor can be connected in series to form a sensor 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 according to claim 1 is 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 so as 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 so as to obtain accurate salinity information.

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