Multipurpose disposable F-P and grating array multiplexed temperature-depth meter

Abstract

The application discloses a multipurpose disposable F-P and grating array multiplexing temperature-depth instrument, and belongs to the technical field of underwater multi-parameter measurement. The multipurpose disposable F-P and grating array multiplexing temperature-depth instrument comprises an outflow end protective cover, a flow inlet cover is threadedly connected to the front of the outflow end protective cover, a stabilizing tail wing is fixed to the rear of the outflow end protective cover through connecting screws, a water inlet is formed in the flow inlet cover, a water outlet is formed in the outflow end protective cover, a water flow channel is formed between the water inlet and the water outlet, a sensing chamber is formed in the inner side of the outflow end protective cover and is communicated with the water flow channel, an induction optical fiber assembly is arranged at the sensing chamber, and a fiber outlet is formed in the rear of the outflow end protective cover and is matched with the induction optical fiber assembly. The multipurpose disposable F-P and grating array multiplexing temperature-depth instrument has the advantages of simple overall structure, low cost and high sensitivity, can be used as a disposable type, and can be used for real-time dynamic measurement of ocean temperature-depth data through a towed line array.

Description

Technical Field

[0001] This invention relates to the field of underwater multi-parameter measurement technology, and in particular to a multi-purpose disposable FP and grating array multiplexed temperature and depth meter. Background Technology

[0002] Naval information systems rely on marine geographical environments such as seabed topography, sediment and depth, marine hydrological environments such as seawater density, currents, temperature, internal waves, mesoscale eddies and sea ice, and marine acoustic environments such as sound speed, sound speed gradient, marine environmental noise information and convergence zones. These information affect functions such as sea area planning, force planning and combat assessment.

[0003] Currently, the detection principle of widely used CTD devices is based on electrical methods. However, these sensors are expensive and not conducive to large-scale monitoring of profiles through networking, which is insufficient to meet the needs of deep-sea exploration and military applications. Compared to traditional electronic CTD sensors, fiber optic sensors do not require preheating or precooling and can directly measure ocean temperature and depth parameters. Furthermore, their temperature measurement response speed is in the millisecond range, and their ocean temperature and depth profile measurement speed is fast, making them suitable for rapid reconstruction of the three-dimensional temperature and depth field underwater, enabling real-time observation of temperature and depth parameters. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-purpose disposable FP and grating array multiplexed temperature and depth meter with a simple overall structure, low cost and high sensitivity. It can be used as a disposable device or as a towed linear array to measure ocean temperature and depth data in real time.

[0005] To achieve the above objectives, the present invention provides a multi-purpose disposable FP and grating array multiplexed temperature and depth meter, including an outlet end cover, an inlet end guide cover threadedly connected to the front of the outlet end cover, a stabilizing tail fin fixed to the rear of the outlet end cover by connecting screws, an inlet on the inlet end guide cover, an outlet on the outlet end cover, a through water flow channel between the inlet and outlet, a sensing chamber connected to the water flow channel on the inner side of the outlet end cover, a sensing fiber optic assembly at the sensing chamber, and a fiber outlet adapted to the sensing fiber optic assembly at the rear of the outlet end cover.

[0006] Preferably, the sensing fiber assembly includes a sensing fiber, and the front end of the sensing fiber is provided with an FBG fiber grating and an FP fiber reflector located in the sensing chamber.

[0007] Preferably, the inside of the outflow end cover is provided with a fiber winding post, and the sensing optical fiber is spirally wound on the fiber winding post.

[0008] Preferably, the surface of the fiber-wound post is threaded.

[0009] Preferably, a transmission fiber is fused to the rear of the sensing fiber, and the transmission fiber extends through the outlet to the outside of the outlet end cover.

[0010] Preferably, the overall structure after the inlet end guide shroud and the outlet end shield are connected is streamlined.

[0011] Preferably, the stabilizing tail fin is annular.

[0012] Therefore, the beneficial effects of the present invention using the above-mentioned multi-purpose disposable FP and grating array multiplexed temperature depth meter are as follows:

[0013] (1) The present invention has low manufacturing cost, is resistant to electromagnetic interference, and has a simple structure.

[0014] (2) The overall structure of the present invention is divided into three parts, which are detachable and can be changed according to actual use to change the actual measurement purpose of the temperature depth meter.

[0015] (3) The present invention can achieve the detection of the parameter to be measured using a small sensor volume.

[0016] (4) The present invention can measure ocean temperature and depth data in real time. The design of the sensor series multiplexing has the advantages of simultaneous measurement of temperature and pressure data and self-compensation.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the multipurpose disposable FP and grating array multiplexed temperature depth meter of the present invention;

[0019] Figure 2 This is a schematic diagram of the internal structure of an embodiment of a multi-purpose disposable FP and grating array multiplexed temperature depth meter according to the present invention.

[0020] Figure Labels

[0021] 1. Inlet guide shield; 2. Inlet; 3. Outlet shield; 4. Outlet; 5. Stabilizing tail fin; 6. Connecting screw; 7. Water flow channel; 8. Sensor chamber; 9. Fiber winding column; 10. Sensing fiber; 11. Transmission fiber; 12. Fiber outlet; 13. FBG fiber optic grating; 14. FP fiber reflector. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] Example 1

[0025] like Figure 1 As shown, this invention provides a multi-purpose disposable FP and grating array multiplexed temperature and depth meter, including an outlet end cover 3. An inlet end guide cover 1 is threadedly connected to the front of the outlet end cover 3 for easy disassembly. A stabilizing tail fin 5 is fixed to the rear of the outlet end cover 3 by connecting screws 6 to stabilize the temperature and depth meter's attitude; this is also easy to disassemble. The overall structure after the inlet end guide cover 1 and the outlet end cover 3 are connected is streamlined. The stabilizing tail fin 5 is annular, and the number and size of the annular rings can be designed and adjusted as needed. In this embodiment, the stabilizing tail fin 5 is a three-ring structure.

[0026] like Figure 2 As shown, the inlet end guide cover 1 has an inlet 2, and the outlet end cover 3 has an outlet 4. The inlet 2 and the outlet 4 are connected by a water flow channel 7. The inner side of the outlet end cover 3 has a sensing chamber 8 connected to the water flow channel 7. The sensing chamber 8 is equipped with a sensing fiber optic assembly, which can make the sensing fiber optic assembly come into contact with water. The rear of the outlet end cover 3 has a fiber outlet 12 that is compatible with the sensing fiber optic assembly.

[0027] The sensing fiber assembly includes a sensing fiber 10, with an FBG fiber grating 13 and an FP fiber reflector 14 located at the front end of the sensing fiber 10 within the sensing chamber 8. The outlet end cover 3 has a fiber winding post 9 inside, with threads on its surface. The sensing fiber 10 is spirally wound around the fiber winding post 9. This spiral winding provides localized sensitivity enhancement, which helps improve detection accuracy.

[0028] A transmission fiber 11 is fused to the rear of the sensing fiber 10. The transmission fiber 11 extends through the fiber outlet 12 to the outside of the outlet end cover 3, and can be connected to the dry-end demodulation system for demodulation and measurement of the information to be measured.

[0029] Working principle:

[0030] The temperature depth meter is placed in water. Water flows into the sensing chamber 8 through the inlet 2 and the water flow channel 7, then comes into contact with the sensing fiber optic assembly and flows out through the outlet 4. Once the sensing fiber optic assembly is in actual contact with the water, the measured parameters in the water can be measured in real time. The light source is connected to the sensing fiber optic assembly's sensing fiber optic 10 through the transmission fiber optic 11. After transmission, the light reaches the sensing fiber optic 10 and first passes through the FBG fiber grating 13. A portion of the light near the reflection wavelength of the FBG fiber grating 13 is reflected, while the remaining transmitted light is incident on the FP fiber mirror 14. Its reflection spectrum is a low-contrast Fabry-Perot cavity interference spectrum. It passes through the FBG fiber grating 13 again, and its transmitted portion is superimposed with the previously reflected light from the FBG fiber grating 13 to form the final returned spectrum. Finally, the dry-end demodulation system demodulates the spectrum to obtain the final measurement information.

[0031] The thermo-depth meter features a streamlined overall structure. The inlet guide shroud 1 is semi-elliptical, the outlet shield 3 is arc-shaped, and the stabilizing tail fin 5 is designed with three rings to counteract the influence of lateral ocean currents during operation and ensure the meter's overall stability during descent. Water flows in through the inlet 2, along the water flow channel 7 to the sensing chamber 8, and then out through the outlet 4, ensuring that the sensing fiber optic assembly can detect external water flow parameters in real time.

[0032] After the sensing fiber 11 extends to the outside through the fiber outlet 12, if it is used in large quantities, the trunk connection fiber can be directly cut short and the temperature depth meter can be discarded. The FBG fiber grating 13 and FP fiber reflector 14 in the sensing chamber 8 can be replaced according to the specific application. Simply cut the sensing fiber 10 on the fiber-wound post 9, use a fiber optic fusion splicer to fuse the required FBG fiber grating and FP fiber reflector, and then place them in the sensing chamber 8.

[0033] Therefore, the present invention adopts the above-mentioned multi-purpose disposable FP and grating array multiplexed temperature and depth meter, which has a simple overall structure, low cost and high sensitivity. It can be used as a disposable device or as a towed linear array to measure ocean temperature and depth data in real time.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A multipurpose disposable F-P and grating array multiplexed thermoprofile instrument, characterized in that: The outflow end shield is threadedly connected with an inflow end fairing in front, and is fixed with a stabilizing tail fin at the back through a connecting screw, a water inlet is formed in the inflow end fairing, a water outlet is formed in the outflow end shield, a water flow channel is formed between the water inlet and the water outlet, a sensing chamber is formed in the inner side of the outflow end shield and is connected with the water flow channel, an inductive optical fiber assembly is arranged at the sensing chamber, and an optical fiber outlet is formed in the back of the outflow end shield and is matched with the inductive optical fiber assembly. The structure of the inflow end fairing and the outflow end shield after being connected is streamlined, and the stabilizing tail fin is annular. The inductive optical fiber assembly comprises a sensing optical fiber, the front end of the sensing optical fiber is provided with an FBG optical fiber grating and an F-P optical fiber mirror in the sensing chamber, and a transmission optical fiber is fused at the back of the sensing optical fiber and extends to the outside of the outflow end shield through the optical fiber outlet. Working principle: the temperature-depth instrument is placed in water, the water flows into the sensing chamber through the water inlet, the water flow channel and the inflow end fairing, and then flows out from the water outlet after contacting the inductive optical fiber assembly; after the inductive optical fiber assembly actually contacts the water, the information of the measured parameter in the water is measured in real time, the light source is connected with the sensing optical fiber of the inductive optical fiber assembly through the transmission optical fiber, and is transmitted to the sensing optical fiber, first passes through the FBG optical fiber grating, part of the light near the reflection wavelength of the FBG optical fiber grating is reflected, the remaining part of the transmitted light is incident on the F-P optical fiber mirror, the reflection spectrum of the reflected light is a low-contrast Fabry-Perot cavity interference spectrum, the transmitted part passes through the FBG optical fiber grating again, and the transmitted part and the reflected light of the FBG optical fiber grating are superimposed to form the final return spectrum, and finally the final measurement information is obtained by a dry end demodulation system.

2. A multipurpose disposable F-P and grating array multiplexed thermoprofile instrument according to claim 1, characterized in that: The inside of the outflow end shield is provided with a fiber winding column, and the sensing optical fiber is spirally wound on the fiber winding column.

3. A multipurpose disposable F-P and grating array multiplexed thermoprofile instrument according to claim 2, characterized in that: The surface of the fiber winding column is provided with threads.

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