Ocean pressure measurement system based on double FP cavities

Abstract

The invention provides an ocean pressure measurement system based on double FP cavities, and relates to the technical field of pressure measurement, and the system comprises a computer, a reading dial plate, a pressure fine adjustment valve, a pressure coarse adjustment valve, a hydraulic machine, a platform, a sensing demodulator, a single-mode transmission optical fiber, a hydraulic pipe, a precise thermostatic bath and a sensor system. Wherein the reading dial plate, the pressure fine adjustment valve and the pressure coarse adjustment valve are connected above the hydraulic machine, the hydraulic machine is located on the platform, one side of the hydraulic machine is connected with one end of the hydraulic pipe, the other end of the hydraulic pipe is connected with the sensor system, and the sensor system is located in the precise thermostatic bath, provided with double FP cavities and used for measuring ocean pressure. The sensor system is connected with one end of the single-mode transmission optical fiber, the other end of the single-mode transmission optical fiber is connected with one end of the sensing demodulator, and the other end of the sensing demodulator is connected with the computer. The problem that the ocean pressure in the deep sea environment is difficult to accurately measure is solved.

Description

Technical Field

[0001] The present specification relates to the technical field of pressure measurement, and in particular to an ocean pressure measurement system based on a double FP cavity. Background Art

[0002] At present, the widely used marine pressure measurement technologies include strain gauge pressure sensors, piezoresistive pressure sensors, and fiber Bragg grating sensors. These technologies each measure external pressure based on different principles. For example, strain gauge sensors rely on the deformation of materials caused by pressure to change the resistance value to measure pressure; while piezoresistive sensors use the piezoresistive effect of semiconductor materials to sense changes in pressure. These sensors have high accuracy and stability under normal temperature and pressure environments. However, extreme temperature changes in deep-sea environments often affect the physical properties of materials, such as thermal expansion, changes in elastic modulus, etc., which in turn lead to measurement errors. For example, under deep-sea conditions, due to the sharp drop in temperature, the characteristics of the sensor material may change significantly, affecting the accuracy of its pressure response. This makes how to effectively eliminate the influence of temperature a key technical challenge to improve the accuracy of deep-sea pressure measurement.

[0003] Fiber optic pressure sensors mainly measure pressure through changes in optical signals in optical fibers, such as interference, intensity, wavelength, and phase. Due to their excellent anti-electromagnetic interference ability and high sensitivity, they can provide accurate measurement results in extreme environments. In particular, optical sensing technology based on Fabry-Perot (FP) cavity has received widespread attention and has become a hot research direction. However, existing FP cavity sensors still have some shortcomings. Since the FP cavity is closed, when the external ambient temperature changes, the temperature inside the FP cavity will change through heat transfer, resulting in a thermal expansion effect, which will affect the pressure in the cavity, and then affect the normal offset of the pressure sensitive diaphragm, causing deviations in the sensor pressure measurement. This makes it difficult for optical sensors that rely solely on the FP cavity to distinguish the superposition effect of pressure and temperature in deep-sea environments, resulting in large errors in measurement data. In addition, the existing technology is easily affected by environmental factors during long-term use, resulting in measurement drift and reduced accuracy, and the sensitivity and stability of the single cavity design are limited, making it difficult to meet the high requirements for accuracy and reliability in deep-sea environments. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides an ocean pressure measurement system based on a dual FP cavity, which solves the problem that it is difficult to accurately measure ocean pressure in a deep-sea environment.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a marine pressure measurement system based on dual FP cavities, comprising: a computer, a dial plate, a pressure fine-adjustment valve, a pressure coarse-adjustment valve, a hydraulic press, a platform, a sensor demodulator, a single-mode transmission optical fiber, a hydraulic pipe, a precision thermostatic bath and a sensor system; wherein the dial plate, the pressure fine-adjustment valve and the pressure coarse-adjustment valve are connected to the top of the hydraulic press, the hydraulic press is located on the platform, one side of the hydraulic press is connected to one end of the hydraulic pipe, the other end of the hydraulic pipe is connected to the sensor system, the sensor system is located in a precision thermostatic bath, has a dual FP cavity, and is used to measure marine pressure, the sensor system is connected to one end of the single-mode transmission optical fiber, the other end of the single-mode transmission optical fiber is connected to one end of the sensor demodulator, and the other end of the sensor demodulator is connected to the computer.

[0006] Furthermore, the hydraulic press is used to provide external pressure for the sensor system; wherein, the pressure fine-tuning valve is used to make fine and precise adjustments to the external pressure provided by the hydraulic press, the pressure coarse-tuning valve is used to make large-scale adjustments to the external pressure provided by the hydraulic press, the indicator dial is used to display the external pressure data currently provided by the hydraulic press, and the hydraulic pipe is used to transmit the external pressure provided by the hydraulic press to the sensor system.

[0007] Furthermore, the sensor system is used to obtain an optical interference signal based on external pressure and temperature; wherein the first FP cavity is encapsulated in a first specific stainless steel structure as a pressure sensitive cavity, and the second FP cavity is encapsulated in a second specific stainless steel structure as a temperature reference cavity, the first FP cavity and the second FP cavity are connected to one end of the single-mode transmission optical fiber, and the heads of the first specific stainless steel structure and the second specific stainless steel structure are tightly connected to the stainless steel packaging system through a threaded structure, and the stainless steel packaging system is located in a precision constant temperature bath, and the precision constant temperature bath is used to provide an initial standard temperature environment for the sensor system.

[0008] Furthermore, the single-mode transmission optical fiber includes a first single-mode optical fiber and a second single-mode optical fiber, one end of the first single-mode optical fiber is connected to the first FP cavity, and one end of the second single-mode optical fiber is connected to the second FP cavity, and the single-mode transmission optical fiber is used to transmit the optical interference signal to the sensor demodulator.

[0009] Furthermore, the sensor demodulator has two channels, which are used to convert the optical interference signals transmitted through the first single-mode optical fiber and the second single-mode optical fiber into pressure electrical signals and temperature electrical signals respectively, and transmit them to the computer; wherein the computer is used to display the received pressure electrical signals and temperature electrical signals as ocean pressure measurement results.

[0010] The beneficial effects of the present invention are as follows: through the innovative dual-cavity design, the system design is simplified, and the influence of temperature on pressure measurement is eliminated by combining optical interferometry and temperature compensation methods, thereby achieving high-precision pressure measurement in marine environments. The system can effectively distinguish the different effects of temperature and pressure on the measurement signal, reduce the measurement error caused by temperature changes, and improve the system response speed and measurement stability. Compared with traditional technical means based on electrical compensation, this technology based on optical signal decoupling has higher accuracy, better real-time performance, and lower system complexity and maintenance costs. Therefore, this solution has significant technical advantages in marine pressure measurement, and is particularly suitable for application scenarios such as marine exploration and energy development that have high requirements for pressure accuracy.

[0011] (1) A dual-cavity design is adopted, that is, in addition to the pressure-sensitive Fabry-Perot cavity, a reference cavity that is only sensitive to temperature is introduced. The reference cavity is structurally designed to be insensitive to pressure, and only changes in the interference signal are caused by temperature changes. By comparing the interference signals of the two cavities, the interference caused by temperature on the pressure-sensitive cavity can be effectively separated, thereby accurately measuring the pressure. This dual-cavity design has achieved significant technical improvements over the traditional single-cavity system, especially when dealing with complex temperature gradient changes in marine environments, the measurement accuracy has been greatly improved.

[0012] (2) Through optical decoupling technology, the effects of temperature and pressure can be directly distinguished at the hardware level. Since the reference cavity and the pressure-sensitive cavity use the same material and optical structure, the thermal expansion effect and the refractive index of the material are the same in the two cavities. Therefore, the interference signal in the reference cavity can be used as a direct reflection of the temperature, and the temperature effect can be directly decoupled through the optical signal difference. Compared with the traditional electrical compensation method, optical decoupling technology avoids the error accumulation and complex calculation process caused by the multi-sensor system, reduces system delay, and has higher real-time and accuracy. The system can quickly respond to pressure changes in deep-sea environments and adapt to rapid fluctuations in the marine environment.

[0013] (3) The dual-chamber structure design integrates pressure and temperature measurements into the same system and separates them directly through optical signals, reducing the need for additional sensors and simplifying system design. At the same time, the long-term stability of optical sensors in high pressure and low temperature environments is better than that of traditional electrical sensors. Therefore, the maintenance cost and failure rate of the overall system are also significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0015] Figure 1 is an exemplary schematic diagram of an ocean pressure measurement system based on a dual FP cavity according to some embodiments of this specification;

[0016] Figure 2 is an exemplary schematic diagram of a sensor system according to some embodiments of the present specification;

[0017] Among them: 1. Computer; 2. Indicator dial; 3. Pressure fine-adjustment valve; 4. Pressure coarse-adjustment valve; 5. Hydraulic press; 6. Platform; 7. Sensor demodulator; 8. Single-mode transmission optical fiber; 8-1. First single-mode optical fiber; 8-2. Second single-mode optical fiber; 9. Hydraulic pipe; 10. Precision constant temperature bath; 11. Sensor system; 11-1. First specific stainless steel structure; 11-2. Second specific stainless steel structure; 11-3. First FP cavity; 11-4. Second FP cavity; 11-5. Stainless steel packaging system. DETAILED DESCRIPTION

[0018] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0019] Embodiment 1

[0020] Figure 1 is an exemplary schematic diagram of an ocean pressure measurement system based on a dual FP cavity according to some embodiments of the present specification.

[0021] In some embodiments, the ocean pressure measurement system based on dual FP cavity may include a computer 1, a dial plate 2, a pressure fine-tuning valve 3, a pressure coarse-tuning valve 4, a hydraulic press 5, a platform 6, a sensor demodulator 7, a single-mode transmission optical fiber 8, a hydraulic pipe 9, a precision thermostatic bath 10 and a sensor system 11; wherein, the dial plate 2, the pressure fine-tuning valve 3 and the pressure coarse-tuning valve 4 are connected to the top of the hydraulic press 5, the hydraulic press 5 is located on the platform 6, one side of the hydraulic press 5 is connected to one end of the hydraulic pipe 9, the other end of the hydraulic pipe 9 is connected to the sensor system 11, the sensor system 11 is located in the precision thermostatic bath 10, has a dual FP cavity, and is used to measure ocean pressure, the sensor system 11 is connected to one end of the single-mode transmission optical fiber 8, the other end of the single-mode transmission optical fiber 8 is connected to one end of the sensor demodulator 7, and the other end of the sensor demodulator 7 is connected to the computer 1.

[0022] In some embodiments, the hydraulic press 5 is placed on the platform 6, the sensor system 11 encapsulated with the FP cavity is installed on the hydraulic pipe 9, and the external pressure environment of the sensor system 11 is adjusted by the pressure control valves 3 and 4. The sensor system 11 is placed in the precision thermostatic bath 10 to provide it with an initial standard temperature environment. The two FP cavities in the sensor system 11 are respectively connected to the two channels of the sensor demodulator 7 through the optical fiber 8. The demodulator converts the collected optical signal into an electrical signal and transmits it to the computer 1, and then the interference signal between the two is displayed and recorded by the computer 1.

[0023] In some embodiments, the hydraulic press 5 is used to provide external pressure to the sensor system 11; wherein the pressure fine-tuning valve 3 is used to make fine and precise adjustments to the external pressure provided by the hydraulic press 5, the pressure coarse-tuning valve 4 is used to make large adjustments to the external pressure provided by the hydraulic press 5, the indicator dial 2 is used to display the external pressure data currently provided by the hydraulic press 5, and the hydraulic pipe 9 is used to transmit the external pressure provided by the hydraulic press 5 to the sensor system 11.

[0024] External pressure data is data reflecting the magnitude of the pressure acting on the sensor system.

[0025] In some embodiments, the sensor system 11 is used to obtain an optical interference signal based on external pressure and temperature; wherein the first FP cavity 11-3 is encapsulated in a first specific stainless steel structure 11-1 as a pressure sensitive cavity, and the second FP cavity 11-4 is encapsulated in a second specific stainless steel structure 11-2 as a temperature reference cavity, the first FP cavity 11-3 and the second FP cavity 11-4 are connected to one end of the single-mode transmission optical fiber 8, and the heads of the first specific stainless steel structure 11-1 and the second specific stainless steel structure 11-2 are tightly connected to the stainless steel packaging system 11-5 through a threaded structure, and the stainless steel packaging system 11-5 is located in a precision constant temperature bath 10, and the precision constant temperature bath 10 is used to provide an initial standard temperature environment for the sensor system 11.

[0026] The optical interference signal includes an interference signal of the pressure sensitive cavity and an interference signal of the temperature reference cavity.

[0027] In some embodiments, the single-mode transmission optical fiber 8 includes a first single-mode optical fiber 8-1 and a second single-mode optical fiber 8-2, one end of the first single-mode optical fiber 8-1 is connected to the first FP cavity 11-3, and one end of the second single-mode optical fiber 8-2 is connected to the second FP cavity 11-4, and the single-mode transmission optical fiber 8 is used to transmit the optical interference signal to the sensor demodulator 7.

[0028] In some embodiments, the sensor system 11 includes a pressure-sensitive Fabry-Perot cavity and a reference cavity that is only sensitive to temperature. Figure 2As shown, the first FP cavity 11-3 and the second FP cavity 11-4 are respectively encapsulated in the first specific stainless steel structure 11-1 and the second specific stainless steel structure 11-2, serving as a pressure sensitive cavity and a temperature reference cavity, respectively. The heads of the first specific stainless steel structure 11-1 and the second specific stainless steel structure 11-2 are tightly matched with the entire external stainless steel encapsulation system 11-5 through a threaded structure, and can be freely disassembled and installed. The other ends of the first single-mode optical fiber 8-1 and the second single-mode optical fiber 8-2 are connected to the sensor demodulator 7. The stainless steel encapsulation system 11-5 is integrated with the hydraulic press 5 and surrounding equipment and finally placed in the environment to be tested.

[0029] In some embodiments, the optical decoupling technology is used to obtain the effect of temperature on measurement in the pressure-sensitive cavity. Specifically, the first FP cavity 11-3 is sensitive to external pressure changes, and the cavity length changes with the increase or decrease of external pressure, thereby changing the interference signal; the second FP cavity 11-4 is designed to be sensitive only to temperature changes. Through reasonable support structure design, the cavity is insensitive to external pressure, but is also sensitive to thermal expansion and refractive index changes of materials caused by temperature; since the two FP cavities are embedded in the same material, the changes caused by temperature are also the same; the interference signal of the pressure-sensitive cavity reflects the combined effect of pressure and temperature, while the temperature reference cavity only reflects the change of temperature; therefore, the effect of temperature on measurement in the pressure-sensitive cavity can be accurately decoupled through the signal of the temperature reference cavity.

[0030] In some embodiments, a dual FP cavity structure is formed by combining a pressure sensitive cavity with a temperature reference cavity. The ambient temperature can be determined based on the change in cavity length of the temperature reference cavity, and the effect of the temperature on the cavity length is then compensated for in the pressure measurement of the pressure sensitive cavity, thereby obtaining the sensitivity of the dual cavity to temperature and pressure as an optical interference signal.

[0031] The dual FP cavity structure is formed by combining the pressure sensitive cavity with the temperature reference cavity. Based on this structural design, the two are independent of each other and will not interfere with each other. Through the calibration system, the sensitivity of the dual cavity to temperature and pressure can be obtained respectively, thereby effectively eliminating the influence of temperature on the pressure measurement accuracy.

[0032] A Fabry-Perot cavity (FP cavity) is a Fabry-Perot interferometer with air as the medium, and its interference fringes have a maximum condition in the cavity; wherein the optical path difference Δ between adjacent light beams of the FP cavity is equal to an integer multiple of the wavelength of the incident light.

[0033] In some embodiments, the expression for the optical path difference between adjacent light beams may be:

[0034] Δ=2L=mλ1=(m+1)λ2;

[0035] Wherein, Δ represents the optical path difference between adjacent light beams, L represents the distance between the end faces of the FP cavity, m represents the m-level maximum condition, λ1 represents the wavelength that satisfies the m-level maximum condition, and λ2 represents the wavelength that satisfies the (m+1)-level maximum condition; at this time, the expression of the wavelength difference between λ1 and λ2 can be:

[0036]

[0037] Among them, Δλ represents the wavelength difference between λ1 and λ2; at this time, the interference maxima of the m-level wavelength and the (m+1)-level wavelength just overlap, and the light waves within the Δλ range will not overlap, and this range is the free spectral range (FSR).

[0038] The Fabry-Perot interferometer is an optical interference instrument that uses the principle of multi-beam interference to accurately measure wavelength or optical path difference. The core components of the Fabry-Perot interferometer are two parallel plane mirrors with high reflectivity. When a beam of light is vertically irradiated between two parallel mirrors, the beam will be reflected multiple times between the two mirrors, and a portion of the light will pass through the mirror each time. Since the light wave travels back and forth between the two mirrors multiple times, there is a certain optical path difference between them. This optical path difference causes a phase difference between the multiple beams of light waves, thus forming an interference phenomenon. When the end face reflectivity is low, the multi-beam interference evolves into a double-beam interference.

[0039] In some embodiments, the free spectral range can be used to calculate the FP cavity facet spacing; wherein, the larger the cavity length of the FP cavity, the smaller the FSR.

[0040] In some embodiments, the expression of the FP cavity end face spacing can be:

[0041]

[0042] In some embodiments, further, the wavelengths of the two peaks are selected to be λ m and λ m+q , the corresponding interference orders are m and m+q respectively, and the expression of the FP cavity end face spacing can be:

[0043]

[0044] In some embodiments, when the optical fiber FP sensor is affected by external environmental factors, the FP cavity length changes and the reflection spectrum changes accordingly. By analyzing and processing the reflection spectrum, the cavity length of the FP cavity can be derived, thereby realizing the monitoring of other physical quantities.

[0045] Through the above calculation method, the cavity length of the interferometer cavity is independent of the light source intensity, which can effectively avoid the influence of the change of the light source intensity on the experiment and improve the demodulation accuracy and stability.

[0046] In some embodiments, the sensor demodulator 7 has two channels, which are used to convert the optical interference signals transmitted through the first single-mode optical fiber 8-1 and the second single-mode optical fiber 8-2 into pressure electrical signals and temperature electrical signals, respectively, and transmit them to the computer 1; wherein the computer 1 is used to display the received pressure electrical signals and the temperature electrical signals as ocean pressure measurement results.

[0047] Ocean pressure measurements are obtained by measuring the ocean pressure without affecting the temperature.

[0048] In some embodiments of the present specification, a dual-FP cavity-based ocean pressure measurement system simplifies the system design through an innovative dual-cavity design, and combines optical interferometry and temperature compensation methods to eliminate the influence of temperature on pressure measurement, thereby achieving high-precision pressure measurement in a marine environment. The system can effectively distinguish the different effects of temperature and pressure on the measurement signal, reduce the measurement error caused by temperature changes, and improve the system response speed and measurement stability. Compared with traditional technical means based on electrical compensation, this technology based on optical signal decoupling has higher accuracy, better real-time performance, and lower system complexity and maintenance costs. Therefore, this solution has significant technical advantages in ocean pressure measurement, and is particularly suitable for application scenarios such as ocean exploration and energy development that require high pressure accuracy.

[0049] (1) A dual-cavity design is adopted, that is, in addition to the pressure-sensitive Fabry-Perot cavity, a reference cavity that is only sensitive to temperature is introduced. The reference cavity is structurally designed to be insensitive to pressure, and only changes in the interference signal are caused by temperature changes. By comparing the interference signals of the two cavities, the interference caused by temperature on the pressure-sensitive cavity can be effectively separated, thereby accurately measuring the pressure. This dual-cavity design has achieved significant technical improvements over the traditional single-cavity system, especially when dealing with complex temperature gradient changes in marine environments, the measurement accuracy has been greatly improved.

[0050] (2) Through optical decoupling technology, the effects of temperature and pressure can be directly distinguished at the hardware level. Since the reference cavity and the pressure-sensitive cavity use the same material and optical structure, the thermal expansion effect and the refractive index of the material are the same in the two cavities. Therefore, the interference signal in the reference cavity can be used as a direct reflection of the temperature, and the temperature effect can be directly decoupled through the optical signal difference. Compared with the traditional electrical compensation method, optical decoupling technology avoids the error accumulation and complex calculation process caused by the multi-sensor system, reduces system delay, and has higher real-time and accuracy. The system can quickly respond to pressure changes in deep-sea environments and adapt to rapid fluctuations in the marine environment.

[0051] (3) The dual-chamber structure design integrates pressure and temperature measurements into the same system and separates them directly through optical signals, reducing the need for additional sensors and simplifying system design. At the same time, the long-term stability of optical sensors in high pressure and low temperature environments is better than that of traditional electrical sensors. Therefore, the maintenance cost and failure rate of the overall system are also significantly reduced.

Claims

1. A dual FP chamber-based ocean pressure measurement system, characterized in that: include: A computer (1), a dial indicator (2), a fine pressure adjustment valve (3), a coarse pressure adjustment valve (4), a hydraulic press (5), a platform (6), a sensor demodulator (7), a single-mode transmission optical fiber (8), a hydraulic pipe (9), a precision thermostatic bath (10) and a sensor system (11); wherein the dial indicator (2), the fine pressure adjustment valve (3) and the coarse pressure adjustment valve (4) are connected above the hydraulic press (5); the hydraulic press (5) is located on the platform (6); one side of the hydraulic press (5) is connected to one end of the hydraulic pipe (9); the other end of the hydraulic pipe (9) is connected to the sensor system (11); the sensor system (11) is located in the precision thermostatic bath (10) and has a double FP cavity for measuring ocean pressure; the sensor system (11) is connected to one end of the single-mode transmission optical fiber (8); the other end of the single-mode transmission optical fiber (8) is connected to one end of the sensor demodulator (7); the other end of the sensor demodulator (7) is connected to the computer (1).

2. The ocean pressure measurement system based on dual FP chamber according to claim 1 is characterized in that: The hydraulic press (5) is used to provide external pressure for the sensor system (11); wherein the pressure fine-tuning valve (3) is used to make fine and precise adjustments to the external pressure provided by the hydraulic press (5), the pressure coarse-tuning valve (4) is used to make large adjustments to the external pressure provided by the hydraulic press (5), the indicator dial (2) is used to display the external pressure data currently provided by the hydraulic press (5), and the hydraulic pipe (9) is used to transmit the external pressure provided by the hydraulic press (5) to the sensor system (11).

3. The ocean pressure measurement system based on dual FP chambers according to claim 1 is characterized in that: The sensor system (11) is used to obtain an optical interference signal based on external pressure and temperature; wherein the first FP cavity (11-3) is encapsulated in a first specific stainless steel structure (11-1) as a pressure sensitive cavity, and the second FP cavity (11-4) is encapsulated in a second specific stainless steel structure (11-2) as a temperature reference cavity; the first FP cavity (11-3) and the second FP cavity (11-4) are connected to one end of the single-mode transmission optical fiber (8); the heads of the first specific stainless steel structure (11-1) and the second specific stainless steel structure (11-2) are tightly connected to a stainless steel encapsulation system (11-5) through a threaded structure; the stainless steel encapsulation system (11-5) is located in a precision thermostatic bath (10); and the precision thermostatic bath (10) is used to provide an initial standard temperature environment for the sensor system (11).

4. The ocean pressure measurement system based on dual FP chambers according to claim 3 is characterized in that: The single-mode transmission optical fiber (8) comprises a first single-mode optical fiber (8-1) and a second single-mode optical fiber (8-2), one end of the first single-mode optical fiber (8-1) is connected to the first FP cavity (11-3), and one end of the second single-mode optical fiber (8-2) is connected to the second FP cavity (11-4), and the single-mode transmission optical fiber (8) is used to transmit the optical interference signal to the sensor demodulator (7).

5. The ocean pressure measurement system based on dual FP chambers according to claim 4 is characterized in that: The sensor demodulator (7) has two channels, which are used to convert the optical interference signals transmitted through the first single-mode optical fiber (8-1) and the second single-mode optical fiber (8-2) into pressure electrical signals and temperature electrical signals respectively, and transmit them to the computer (1); wherein the computer (1) is used to display the received pressure electrical signals and temperature electrical signals as ocean pressure measurement results.

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