Temperature-depth sensor of self-melting type cascade F-P cavity and packaging method of temperature-depth sensor

Abstract

The invention discloses a temperature-depth sensor of a self-melting cascade F-P cavity and a packaging method of the temperature-depth sensor. The temperature-depth sensor comprises a probe protection shell, a probe, a tank body upper cover, a tank body and a tank body lower cover, the tank body, the tank body upper cover and the tank body lower cover, the probe and the tank body upper cover, and the probe protection shell and the probe are respectively sealed and fixed through fixing screws and sealing rubber rings; a water inlet groove opening is formed in the center position of the probe protection shell, a ceramic ferrule preformed hole is formed in the center position of the probe, and a ceramic ferrule is arranged in the ceramic ferrule preformed hole; a probe diaphragm bonding groove is formed between the top of the ceramic ferrule preformed hole and the water inlet groove opening, and a cascade F-P external diaphragm is bonded between the top of the ceramic ferrule preformed hole and the water inlet groove opening in a sealing manner; an equipment fixing assembly is arranged in the tank body, and a photoelectric module is installed on the equipment fixing assembly. According to the temperature-depth sensor of the self-melting cascade F-P cavity and the packaging method thereof, the temperature-depth sensor has the advantages of being small in size, low in cost, convenient for large-scale production and the like, and temperature data of seawater of different depths can be measured and recorded.

Description

Technical Field

[0001] The present invention relates to the technical field of seawater temperature measurement, and in particular to a temperature-depth sensor with a self-fusing cascade FP cavity and a packaging method thereof. Background Art

[0002] In recent years, fiber optic sensors have become a research hotspot in marine environmental monitoring due to their small size, low cost, resistance to electromagnetic interference, and long-distance transmission capabilities. However, fiber optic sensors are inherently fragile and susceptible to external influences. This can lead to measurement errors or even damage, resulting in significant economic losses. Appropriate packaging for fiber optic sensors can reduce these errors, extend sensor life, and ensure data accuracy. Furthermore, most fiber optic temperature and depth sensors lack self-melting capabilities. Summary of the Invention

[0003] The purpose of the present invention is to provide a self-fusing cascade FP cavity temperature-depth sensor and its packaging method, which has the advantages of small size, low cost, and convenience for large-scale production. It can be dropped into seawater to measure and record the temperature data of seawater at different depths.

[0004] To achieve the above-mentioned objectives, the present invention provides a temperature and depth sensor with a self-melting cascade FP cavity, comprising a probe protective shell, a probe, a tank upper cover, a tank body and a tank lower cover; the tank body and the tank upper cover, as well as the tank lower cover, the probe and the tank upper cover, and the probe protective shell and the probe are sealed and fixed by fixing screws and sealing rubber rings respectively; a water inlet notch is provided at the center of the probe protective shell, a ceramic ferrule pre-hole is provided at the center of the probe and a ceramic ferrule is built in; a probe diaphragm bonding groove is provided between the top of the ceramic ferrule pre-hole and the water inlet notch and a cascade FP external diaphragm is sealed and bonded thereto; an equipment fixing assembly is provided inside the tank body, and an optoelectronic module is installed on the equipment fixing assembly.

[0005] Preferably, an upper cover outer connecting hole is provided at the edge of the upper cover of the tank body, a tank body connecting hole corresponding to the upper cover outer connecting hole is provided on the top of the tank body, and is fixed by the fixing screws; a lower cover connecting hole is provided at the edge of the lower cover of the tank body, a tank body lower connecting hole corresponding to the lower cover connecting hole is provided at the bottom of the tank body, and is fixed by the fixing screws; the upper and lower ends of the tank body are circumferentially provided with reserved grooves for the tank body watertight rubber ring and the sealing rubber ring is built-in.

[0006] Preferably, a through groove is provided at the center of the upper cover of the tank body, and a reserved notch for the upper cover watertight rubber ring located on the top of the upper cover of the tank body is provided on the outer circumference of the through groove and the sealing rubber ring is built in; an inner connecting hole of the upper cover is provided at the edge of the through groove, and a lower connecting hole of the probe corresponding to the inner connecting hole of the upper cover is provided at the bottom of the probe, and is fixed by the fixing screw.

[0007] Preferably, a reserved groove for the probe watertight rubber ring located at the top of the probe is opened circumferentially on the outer side of the reserved hole of the ceramic core and the sealing rubber ring is built in; a probe upper connection hole is opened on the top of the probe, and a probe protective shell connection hole corresponding to the probe upper connection hole is opened on the probe protective shell and is fixed by the fixing screw.

[0008] Preferably, the equipment fixing assembly includes an upper support plate and a lower support plate distributed up and down, the upper support plate and the lower support plate are connected and fixed by support columns, and the lower support plate is fixed to the lower cover of the tank body by connecting studs.

[0009] Preferably, the optoelectronic module includes a circulator fixed on the upper support plate and a light source, a demodulator, an FPGA circuit board and a power supply fixed on the lower support plate. The light source and the demodulator are electrically connected to the FPGA circuit board, and the FPGA circuit board is electrically connected to the power supply.

[0010] Preferably, the thickness of the probe protection shell, the tank upper cover, the tank body and the tank lower cover is in the range of 3 to 5 mm.

[0011] Preferably, the probe protective shell, the probe, the tank upper cover, the tank body and the tank lower cover are all made of 304 stainless steel.

[0012] The present invention also provides a packaging method for a temperature-depth sensor of a self-fusing cascade FP cavity, comprising the following steps:

[0013] S1. First, package the probe. Attach the prepared cascaded FP outer diaphragm to the probe diaphragm bonding groove using waterproof glue. Then, insert the prepared ceramic ferrule with the cascaded FP inner diaphragm into the pre-prepared hole for the ceramic ferrule. Adjust the insertion position of the ceramic ferrule until the expected spectrum is obtained. Finally, secure the ceramic ferrule in the pre-prepared hole with waterproof glue.

[0014] S2. Encapsulate and assemble the optoelectronic module inside the tank body, connect the light source and demodulator to the FPGA circuit board, then connect the FPGA circuit board to the power supply, and finally fix them all to the lower support plate and the circulator to the upper support plate; connect the upper and lower support plates through support columns and secure them with nuts connected to the threads on the outer sides of the support columns;

[0015] S3. Connect the assembled equipment fixing assembly to the lower cover of the tank body through the connecting studs and secure it with nuts. Then, insert the fixed lower cover into the tank body and fill the sealing rubber ring in the reserved groove for the watertight rubber ring on the lower side of the tank body. Then, connect the upper cover of the tank body to the tank body and fill the sealing rubber ring in the reserved groove for the watertight rubber ring on the upper side of the tank body. Finally, connect the upper cover of the tank body to the tank body by passing the fixing screws through the threaded structure of the connecting hole on the outer side of the upper cover and the connecting hole on the tank body. Finally, connect the lower cover of the tank body to the tank body by passing the fixing screws through the threaded structure of the connecting hole on the lower cover and the lower connecting hole on the tank body, thereby completing the encapsulation of the tank body.

[0016] S4. Finally, fill the sealing rubber ring in the reserved groove of the probe watertight rubber ring, and use the fixing screw to pass through the threaded structure of the probe protective shell connection hole and the probe upper connection hole to complete the connection between the probe protective shell and the probe; fill the sealing rubber ring in the reserved groove of the upper cover watertight rubber ring, and use the fixing screw to pass through the threaded structure of the probe lower connection hole and the inner connection hole of the upper cover to complete the connection between the probe and the tank cover. At this point, the connection of the entire packaging structure is completed.

[0017] Therefore, the beneficial effects of the present invention using the above-mentioned self-fusing cascade FP cavity temperature-depth sensor and its packaging method are as follows:

[0018] (1) The temperature-depth sensor of the present invention has the advantages of small size, low cost, and convenience for large-scale production. It is resistant to wind and waves, collisions, and corrosion. It can be thrown into seawater to measure and record the temperature data of seawater at different depths.

[0019] (2) The packaging structure of the temperature-depth sensor of the present invention can protect the sensor device from the pressure of seawater at a depth of 200m, and can achieve multi-purpose use by replacing the probe, thereby reducing the cost of temperature measurement.

[0020] (3) The temperature-depth sensor of the present invention has self-melting capability and can store the measured temperature data in the packaging structure, meeting the experimental requirements of long-term temperature measurement and facilitating operation and disposable measurement.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a self-fusing cascade FP cavity temperature-depth sensor and its packaging method according to the present invention;

[0023] Figure 2 This is a schematic diagram of the can packaging structure of a self-melting cascade FP cavity temperature-depth sensor and its packaging method embodiment of the present invention;

[0024] Figure 3It is a schematic diagram of the probe packaging structure of a self-fusing cascade FP cavity temperature-depth sensor and a packaging method embodiment of the present invention.

[0025] Reference numerals

[0026] 1. Probe protective shell; 2. Probe; 3. Tank cover; 4. External connection hole of the upper cover; 5. Connection hole on the tank body; 6. Tank body; 7. Reserved notch for the tank body watertight rubber ring; 8. Lower connection hole of the tank body; 9. Connection hole of the lower cover; 10. Tank lower cover; 11. Circulator; 121. Upper support plate; 122. Lower support plate; 13. Support column; 14. Light source; 15. Demodulator; 16. FPGA circuit board; 17. Power supply; 18. Connecting stud; 19. Probe protective shell connection hole; 20. Water inlet notch; 21. Probe diaphragm bonding groove; 22. Reserved notch for the probe watertight rubber ring; 23. Upper connection hole of the probe; 24. Lower connection hole of the probe; 25. Reserved notch for the upper cover watertight rubber ring; 26. Connection hole on the inner side of the upper cover; 27. Reserved hole for the ceramic ferrule. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0028] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0029] Example 1

[0030] like Figure 1 As shown, the present invention provides a self-melting cascade FP cavity temperature and depth sensor, including a probe protective shell 1, a probe 2, a tank upper cover 3, a tank body 6 and a tank lower cover 10. The tank body 6 and the tank upper cover 3 and the tank lower cover 10, the probe 2 and the tank upper cover 3, and the probe protective shell 1 and the probe 2 are sealed and fixed by fixing screws and sealing rubber rings, respectively, which can effectively prevent water from entering the temperature and depth sensor.

[0031] Specifically, the upper cover 3 has an outer connection hole 4 at its edge, and the top of the tank body 6 has a corresponding connection hole 5, secured with screws. The lower cover 10 has a lower connection hole 9 at its edge, and the bottom of the tank body 6 has a lower connection hole 8, secured with screws. Both the upper and lower ends of the tank body 6 have circumferential notches 7 for the tank's watertight rubber ring, each housing a built-in rubber sealing ring.

[0032] A through slot is defined at the center of the tank cover 3. A notch 25 is defined around the outside of the slot for the watertight rubber gasket at the top of the tank cover 3, housing a built-in rubber sealing ring. An inner cover connection hole 26 is defined at the edge of the slot. The probe 2 has a lower connection hole 24 at the bottom, corresponding to this inner cover connection hole 26 and secured with a set screw.

[0033] A water inlet notch 20 is provided at the center of the probe protective shell 1, and a ceramic ferrule pre-hole 27 is provided at the center of the probe 2 with a ceramic ferrule built in. A probe diaphragm bonding groove 21 is provided between the top of the ceramic ferrule pre-hole 27 and the water inlet notch 20, and a cascade FP external diaphragm is sealed and bonded thereto. The cooperation between the cascade FP external diaphragm and the ceramic ferrule enables temperature and depth measurement.

[0034] A notch 22 for the probe's watertight rubber ring is located on the top of the probe 2, circumferentially around the ceramic ferrule's pre-reserved hole 27. This notch houses a sealing rubber ring. A probe upper connection hole 23 is defined at the top of the probe 2. The probe protective housing 1 has a corresponding connection hole 19, secured to the probe upper connection hole 23.

[0035] An equipment fixing assembly is provided inside the tank body 6, and the equipment fixing assembly includes an upper support plate 121 and a lower support plate 122 distributed up and down. The upper support plate 121 and the lower support plate 122 are connected and fixed by a support column 13, and the lower support plate 122 is fixed to the lower cover 10 of the tank body by a connecting stud 18.

[0036] An optoelectronic module is installed on the fixed component of the equipment. The optoelectronic module includes a circulator 11 fixed on the upper support plate 121 and a light source 14, a demodulator 15, an FPGA circuit board 16 and a power supply 17 fixed on the lower support plate 122. The light source 14 and the demodulator 15 are electrically connected to the FPGA circuit board 16, and the FPGA circuit board 16 is electrically connected to the power supply 17 to ensure normal power supply to the FPGA circuit board 16.

[0037] The thickness of the probe protective housing 1, tank cover 3, tank body 6, and tank lower cover 10 ranges from 3 to 5 mm and can be adjusted to suit actual needs. The probe protective housing 1, probe 2, tank cover 3, tank body 6, and tank lower cover 10 are all made of 304 stainless steel, ensuring the structural strength of the temperature and depth sensor, enabling it to withstand pressure depths up to 200 meters and resist wind and waves, collisions, and corrosion.

[0038] A packaging method for a self-fusing cascade FP cavity temperature-depth sensor comprises the following steps:

[0039] S1. First, package the probe part. Attach the prepared cascaded FP external diaphragm to the probe diaphragm bonding groove using waterproof glue. Then, insert the prepared ceramic ferrule with the cascaded FP internal diaphragm into the ceramic ferrule reserved hole. Adjust the insertion position of the ceramic ferrule until the expected spectrum is obtained. Finally, fix the ceramic ferrule in the ceramic ferrule reserved hole with waterproof glue.

[0040] S2. Package and assemble the optoelectronic modules inside the tank body, connect the light source, demodulator and FPGA circuit board, then connect the FPGA circuit board to the power supply, and finally fix them together on the lower support plate, and fix the circulator on the upper support plate; connect the upper and lower support plates through support columns, and fix them with nuts connected to the threads on the outside of the support columns.

[0041] S3. Connect the assembled equipment fixing assembly to the lower cover of the tank body through the connecting studs and fix it with nuts. Then insert the fixed lower cover of the tank body into the tank body and fill the sealing rubber ring in the reserved groove of the watertight rubber ring of the tank body on the lower side. Then connect the upper cover of the tank body to the tank body and fill the sealing rubber ring in the reserved groove of the watertight rubber ring of the tank body on the upper side. Finally, complete the connection between the upper cover of the tank body and the tank body by passing the fixing screws through the threaded structure of the connecting hole on the outer side of the upper cover and the connecting hole on the tank body. Then complete the connection between the lower cover of the tank body and the tank body by passing the fixing screws through the threaded structure of the connecting hole of the lower cover and the lower connecting hole of the tank body to achieve the encapsulation of the tank body part.

[0042] S4. Finally, fill the sealing rubber ring in the reserved groove of the probe watertight rubber ring, and use the fixing screw to pass through the threaded structure of the probe protective shell connection hole and the probe upper connection hole to complete the connection between the probe protective shell and the probe; fill the sealing rubber ring in the reserved groove of the upper cover watertight rubber ring, and use the fixing screw to pass through the threaded structure of the probe lower connection hole and the inner connection hole of the upper cover to complete the connection between the probe and the tank cover. At this point, the connection of the entire packaging structure is completed.

[0043] As the temperature-depth sensor sinks deeper into the water, the seawater pressure on it increases, leading to corrosion. Furthermore, during the jettisoning process, the sensor may collide with hard objects, ultimately causing it to malfunction or even completely fail. Encapsulating the temperature-depth sensor can address these issues, protecting it from damage. This ensures that the sensor's direct sensing area is exposed to seawater, while the remaining area remains dry and safe, extending its lifespan.

[0044] Working principle: When the temperature and depth sensor is dropped into the water, the internal diaphragm of the cascade FP will be affected by the seawater temperature and the external diaphragm of the cascade FP will be affected by the seawater pressure, which together cause the received reflected light to change, thereby achieving temperature and depth measurement.

[0045] Temperature sensitivity S of the temperature depth sensor T The expression is as follows:

[0046]

[0047] in, Thermo-optic coefficient (TOC) of the FP cavity is expressed in RIU / ℃. It represents the thermal expansion coefficient (TEC) of the FP cavity, in 1 / °C.

[0048] The expression of pressure sensitivity S of temperature-depth sensor is as follows:

[0049]

[0050] Where E is the elastic modulus, h is the diaphragm thickness, μ is the diaphragm Poisson's ratio, d is the cavity length of the FP interferometer cavity, λ m is the trough wavelength of a certain interference order in the reflection spectrum, and the diaphragm radius is R.

[0051] Therefore, when the external temperature changes, the optical path difference of the cascaded FP internal diaphragm will change due to thermal expansion and thermo-optical effects, causing the wavelength of the reflected spectrum trough to shift. Demodulating this change reflects the change in seawater temperature. When the external pressure changes, the external diaphragm of the cascaded FP will undergo different deformations with the pressure change, causing the optical path difference of the external cavity to change, which in turn causes the wavelength of the reflected spectrum trough to shift. Demodulating this change reflects the change in seawater pressure.

[0052] Therefore, the present invention adopts the above-mentioned self-fusing cascade FP cavity temperature-depth sensor and its packaging method, which has the advantages of small size, low cost, and convenience for large-scale production, and can measure and record the temperature data of seawater at different depths.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A self-melting cascade FP cavity temperature and depth sensor, characterized by: It includes a probe protective shell, a probe, a tank upper cover, a tank body and a tank lower cover; the tank body and the tank upper cover, the tank lower cover, the probe and the tank upper cover, and the probe protective shell and the probe are sealed and fixed by fixing screws and sealing rubber rings respectively; a water inlet notch is provided at the center of the probe protective shell, and a ceramic ferrule pre-hole is provided at the center of the probe and a ceramic ferrule is built in; a probe diaphragm bonding groove is provided between the top of the ceramic ferrule pre-hole and the water inlet notch and a cascade FP external diaphragm is sealed and bonded; an equipment fixing assembly is provided inside the tank body, and an optoelectronic module is installed on the equipment fixing assembly.

2. The self-fusing cascade FP cavity temperature-depth sensor according to claim 1, characterized in that: An outer connecting hole of the upper cover is provided at the edge of the upper cover of the tank body, and a connecting hole on the tank body corresponding to the outer connecting hole of the upper cover is provided on the top of the tank body, and is fixed by the fixing screws; a lower cover connecting hole is provided at the edge of the lower cover of the tank body, and a lower connecting hole on the tank body corresponding to the connecting hole of the lower cover is provided at the bottom of the tank body, and is fixed by the fixing screws; reserved grooves for the tank body watertight rubber ring are circumferentially provided at the upper and lower ends of the tank body and the sealing rubber ring is built-in.

3. The self-fusing cascade FP cavity temperature-depth sensor according to claim 1, characterized in that: A through groove is provided at the center of the upper cover of the tank body, and a reserved notch for the upper cover watertight rubber ring located on the top of the upper cover of the tank body is provided on the outer circumference of the through groove and the sealing rubber ring is built in; an inner connecting hole of the upper cover is provided at the edge of the through groove, and a lower connecting hole of the probe corresponding to the inner connecting hole of the upper cover is provided at the bottom of the probe, and is fixed by the fixing screw.

4. The self-fusing cascade FP cavity temperature-depth sensor according to claim 1, characterized in that: A reserved notch for the probe watertight rubber ring located on the top of the probe is opened on the circumference of the outer side of the ceramic core reserved hole and the sealing rubber ring is built in; a probe upper connection hole is opened on the top of the probe, and a probe protective shell connection hole corresponding to the probe upper connection hole is opened on the probe protective shell and is fixed by the fixing screw.

5. The self-fusing cascade FP cavity temperature-depth sensor according to claim 1, characterized in that: The equipment fixing assembly includes an upper support plate and a lower support plate distributed up and down, the upper support plate and the lower support plate are connected and fixed by support columns, and the lower support plate is fixed to the lower cover of the tank body by connecting studs.

6. The self-fusing cascade FP cavity temperature-depth sensor according to claim 5, characterized in that: The optoelectronic module includes a circulator fixed on the upper support plate and a light source, a demodulator, an FPGA circuit board and a power supply fixed on the lower support plate. The light source and the demodulator are electrically connected to the FPGA circuit board, and the FPGA circuit board is electrically connected to the power supply.

7. The self-fusing cascade FP cavity temperature-depth sensor according to claim 1, characterized in that: The thickness of the probe protection shell, the tank upper cover, the tank body and the tank lower cover is within the range of 3 to 5 mm.

8. The self-fusing cascade FP cavity temperature-depth sensor according to claim 1, characterized in that: The probe protective shell, the probe, the tank upper cover, the tank body and the tank lower cover are all made of 304 stainless steel.

9. The packaging method of a self-fusing cascade FP cavity temperature-depth sensor according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. First, package the probe. Attach the prepared cascaded FP outer diaphragm to the probe diaphragm bonding groove using waterproof glue. Then, insert the prepared ceramic ferrule with the cascaded FP inner diaphragm into the pre-prepared hole for the ceramic ferrule. Adjust the insertion position of the ceramic ferrule until the expected spectrum is obtained. Finally, secure the ceramic ferrule in the pre-prepared hole with waterproof glue. S2. Encapsulate and assemble the optoelectronic module inside the tank body, connect the light source and demodulator to the FPGA circuit board, then connect the FPGA circuit board to the power supply, and finally fix them all to the lower support plate and the circulator to the upper support plate; connect the upper and lower support plates through support columns and secure them with nuts connected to the threads on the outer sides of the support columns; S3. Connect the assembled equipment fixing assembly to the lower cover of the tank body through the connecting studs and secure it with nuts. Then, insert the fixed lower cover into the tank body and fill the sealing rubber ring in the reserved groove for the watertight rubber ring on the lower side of the tank body. Then, connect the upper cover of the tank body to the tank body and fill the sealing rubber ring in the reserved groove for the watertight rubber ring on the upper side of the tank body. Finally, connect the upper cover of the tank body to the tank body by passing the fixing screws through the threaded structure of the connecting hole on the outer side of the upper cover and the connecting hole on the tank body. Finally, connect the lower cover of the tank body to the tank body by passing the fixing screws through the threaded structure of the connecting hole on the lower cover and the lower connecting hole on the tank body, thereby completing the encapsulation of the tank body. S4. Finally, fill the sealing rubber ring in the reserved groove of the probe watertight rubber ring, and use the fixing screw to pass through the threaded structure of the probe protective shell connection hole and the probe upper connection hole to complete the connection between the probe protective shell and the probe; fill the sealing rubber ring in the reserved groove of the upper cover watertight rubber ring, and use the fixing screw to pass through the threaded structure of the probe lower connection hole and the inner connection hole of the upper cover to complete the connection between the probe and the tank cover. At this point, the connection of the entire packaging structure is completed.

Images