High-precision temperature and pressure measuring device and method

Abstract

The invention provides a high-precision temperature and pressure measuring device and method. The method comprises the steps of separating a temperature amount and a pressure amount by using temperature compensation, eliminating a vibration interference error by using differential measurement, and improving sensitivity by using a weak measurement technology. The system adopts a four-section grating design, and realizes differentiated measurement of temperature quantity and pressure intensity quantity. The method breaks through the limitation that a traditional fiber grating sensor cannot distinguish the temperature amount, the pressure intensity amount and the vibration interference error, and the measurement sensitivity and precision are remarkably improved. According to the invention, high-precision and high-sensitivity real-time measurement can be carried out on the environment temperature and pressure intensity, and the application scenarios of numerous measurement systems taking weak measurement as a theoretical basis are greatly expanded.

Description

Technical Field

[0001] This invention relates to the field of optical sensing technology, specifically to a high-precision temperature and pressure measurement device and method, and more specifically to a fiber optic grating sensing system and method for simultaneous detection of multiple parameters, particularly to a multi-parameter detection scheme that integrates the quantum weak measurement principle and fiber optic grating sensing technology, applicable to high-sensitivity fiber optic sensing application scenarios. Background Technology

[0002] In pressure and temperature measurement, fiber Bragg gratings can sensitively sense changes in pressure and temperature within an environment. In a specific environment, incident light is reflected within the grating, received by the measuring end, and collected to form a spectrum. The reflected spectrum will shift to some extent in different environments, reflecting strain and temperature changes near the grating. Therefore, temperature and external force data can be obtained by calculating the change in the center wavelength.

[0003] Related technologies use a single grating to achieve pressure and temperature sensing based on the center wavelength offset. However, a single grating is affected by both temperature and pressure simultaneously, making it impossible to separate pressure and temperature information. Treating the wavelength offset as being affected by either temperature or pressure alone introduces significant errors in real-world measurement environments, resulting in low measurement accuracy. Furthermore, vibration interference in the measurement environment causes dynamic pressure changes, affecting real-time grating length variations and wavelength offset, thus limiting sensor sensitivity and accuracy.

[0004] Therefore, this invention focuses on how to simultaneously detect two parameters, pressure and temperature. Through structural design, it separates the temperature and pressure sensing parameters and eliminates vibration interference, achieving high-precision temperature and pressure sensing. This invention can be applied in fields such as seawater temperature and pressure detection, and oil field development detection. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide a high-precision temperature and pressure measurement device and method.

[0006] A high-precision temperature and pressure measuring device according to the present invention includes: a broadband light source 1, a pre-selection module, a sensing module 6, a first fiber polarization controller 7, a second fiber polarization controller 8, a post-selection module 9, and a spectrometer 10. The broadband light source 1 is used to acquire broadband light that meets preset requirements; The pre-selection module is used to preprocess the acquired broadband light to obtain preprocessed broadband light. The sensing module 6 is used to sense changes in ambient temperature and pressure based on pre-processed broadband light and fiber optic grating. The first fiber polarization controller 7 and the second fiber polarization controller 8 are used to adjust the polarization state of the reflected beam of the sensing module 6. The post-selection module 9 and the spectrometer 10 are used to measure temperature and pressure based on the adjusted reflected beam.

[0007] Preferably, the pre-selection module includes: a first polarizer 2, a polarizing beam splitter 3, a first circulator 4, and a second circulator 5; The first polarizer 2 is used to modulate the acquired broadband light into initial state light; The polarization beam splitter 3 is used to separate the initial state light into horizontally polarized light and vertically polarized light; The horizontally polarized light sequentially passes through the second circulator 5, the sensing module 6, and the second fiber polarization controller 8 to form a second optical path channel; the second optical path channel is used to propagate and adjust the horizontally polarized light. The vertically polarized light sequentially passes through the first circulator 4, the sensing module 6, and the first fiber polarization controller 7 to form a first optical path channel; the first optical path channel is used to propagate and adjust the vertically polarized light.

[0008] Preferably, the broadband light source 1 is connected to the first polarizer 2; the first polarizer 2 is connected to the polarization beam splitter 3; the polarization beam splitter 3 is connected to the first circulator 4 and the second circulator 5 respectively; the second circulator 4 is connected to the sensing module 6 and the first fiber polarization controller 7 respectively; the second circulator 5 is connected to the sensing module 6 and the second fiber polarization controller 8 respectively; the first fiber polarization controller 7 and the second fiber polarization controller 8 are connected to the post-selection module 9, and the post-selection module 9 is connected to the spectrometer 10.

[0009] Preferably, the sensing module 6 is a spherical device used to fix the position of the fiber optic grating; The surface of the spherical device is divided into a first region Q1, a second region Q2, a third region Q3, and a fourth region Q4; a first fiber grating, a second fiber grating, a third fiber grating, and a fourth fiber grating are respectively attached to the surface of the regions; The horizontally polarized light is connected to the second circulator 5, the first fiber optic grating, and the second fiber optic grating to form a second optical path channel; The vertically polarized light is connected to the first circulator 4, the third fiber grating, and the fourth fiber grating to form a first optical path channel; The first and third fiber gratings form a temperature sensing group; the second and fourth fiber gratings form a pressure sensing group, and the second and fourth fiber gratings are mounted on elastic diaphragms in the second region Q2 and the fourth region Q4; the elastic diaphragms deform under external pressure in the closed air chamber structure to amplify the pressure strain; wherein the external pressure includes the static pressure of the measurement environment and vibration interference within the environment.

[0010] Preferably, the post-selection module 9 includes: a first fiber beam splitter 11, a beam splitter 12, a first phase compensator 13, a second phase compensator 14, a second polarizer 15, a third polarizer 16, a first fiber collimator 17, a second fiber collimator 18, and a second fiber beam splitter 19. The first fiber beam splitter 11 is connected to the beam splitter 12; the beam splitter 12 is connected to the first phase compensator 13 and the second phase compensator 14 respectively; the first phase compensator 13 is connected to the second polarizer 15; the second polarizer 15 is connected to the first fiber collimator 17; the second phase compensator 14 is connected to the third polarizer 16; the third polarizer 16 is connected to the second fiber collimator 18; the first fiber collimator 17, the second fiber collimator 18 and the second fiber beam splitter 19 are connected.

[0011] According to the high-precision temperature and pressure measurement method provided by the present invention, the following steps are performed based on the high-precision temperature and pressure measurement device described above: Step S1: Obtain broadband light that meets the preset requirements through broadband light source 1; Step S2: Broad-spectrum light that meets the preset requirements passes through the pre-selection module to obtain horizontally polarized light and vertically polarized light; Step S3: Sensing module 6 senses changes in ambient temperature and pressure based on horizontally polarized light and vertically polarized light. Step S4: Adjust the polarization state of the reflected beam of the sensing module 6 by using the first fiber polarization controller 7 and the second fiber polarization controller 8. Step S5: Then select module 9 to measure temperature and pressure based on the adjusted reflected beam.

[0012] Preferably, step S1 includes: acquiring broadband light that meets preset requirements based on a preset spectral frequency using a broadband light source; wherein the wavelength range corresponding to the full width at half maximum (FWHM) of the broadband light that meets the preset requirements at the center wavelength needs to completely cover the reflection spectrum of the fiber grating.

[0013] The fiber gratings of the temperature sensing group have the same reflection spectrum, and the fiber gratings of the pressure sensing group have the same reflection spectrum; moreover, the reflection spectra of the fiber gratings of the temperature and pressure sensing groups have a large spectral interval.

[0014] Preferably, step S2 includes: Step S2.1: Modulate the acquired broadband light into initial state light using the first polarizer 2; Step S2.2: The initial state light is separated into horizontally polarized light and vertically polarized light by polarization beam splitter 3; Step S2.3: Horizontally polarized light sequentially passes through the second circulator 5, the sensing module 6, and the second fiber polarization controller 8 to form a second optical path channel; the second optical path channel is used to propagate and adjust the horizontally polarized light; Step S2.4: Vertically polarized light sequentially passes through the first circulator 4, the sensing module 6, and the first fiber polarization controller 7 to form a first optical path channel; the first optical path channel is used to propagate and adjust vertically polarized light.

[0015] Preferably, step S4 includes: After the horizontally polarized light is adjusted by the second fiber polarization controller 8, the adjusted horizontally polarized light is obtained. ; After the vertically polarized light is adjusted by the first fiber polarization controller 7, the adjusted horizontally polarized light is obtained. .

[0016] Preferably, step S5 includes: adjusted horizontally polarized light And adjusted horizontally polarized light The first fiber optic beam splitter 11 combines the light from the same sensing group. The state after combining temperature sensing elements is:

[0017] in, The center angular frequency of the fiber grating after beam combining. ; The change in temperature Temperature coefficient; This is the adjusted horizontally polarized light; This is the adjusted vertically polarized light; The imaginary unit, The phase difference of the fiber gratings between the temperature sensing groups of channel one and channel two; The fiber grating reflectance spectral distribution function; The state after the pressure sensing assembly is:

[0018] in, The center angular frequency of the fiber grating after beam combining. ; The pressure sensitivity coefficient, The change in vibration The imaginary unit, The phase difference of the fiber gratings in the pressure sensing groups of channel one and channel two; The light reflected from the four fiber gratings is combined, and then split into two combined beams by beam splitter 12; the two-way selection state is... , β The angles selected later represent the transmission axis angles of the second polarizer 15 and the third polarizer 16, respectively. Spectral distribution

[0019]

[0020] in, , The phase difference of the same set of fiber gratings The phase compensation for the phase shifter is controlled by the first phase compensator 13 and the second phase compensator 14, respectively. These are the reflection spectral linewidths of the fiber Bragg gratings for the temperature and pressure sensing groups, respectively. After selection, the two fibers are coupled into an optical fiber via the first fiber collimator 17 and the first fiber collimator 18, and then combined via the second fiber splitter 19. Spectral analysis is performed by the spectrometer 10, and the average spectral frequency shift is calculated to be...

[0021]

[0022] The magnitudes of the two weak values ​​represent the amplification factor for the spectral frequency shift:

[0023] Therefore, through calculation, we can obtain...

[0024] .

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention achieves the separation of temperature and pressure information within the same sensor, allowing for the separate measurement of temperature and pressure values; 2. This invention overcomes the problem that existing pressure sensors are greatly affected by vibration interference by using a differential structure to eliminate vibration interference errors. 3. The present invention has a simple structure and is easy to use, thus overcoming the shortcomings of the prior art; 4. This invention expands the application scenarios of many measurement systems based on weak measurement theory. Attached Figure Description

[0026] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a block diagram of a high-precision temperature and pressure measurement device.

[0027] Figure 2 This is a schematic diagram of the sensing device.

[0028] Figure 3 This is a schematic diagram of the pressure sensing group.

[0029] Figure 4 This is a schematic diagram of a pressure sensing group under conditions of no vibration interference.

[0030] Figure 5 This is a schematic diagram of a pressure sensing group subject to vibration interference.

[0031] Figure 6 A detailed schematic diagram of the device for the subsequent selection process.

[0032] Wherein, 1-broadband light source; 2-first polarizer; 3-polarization beam splitter; 4-first circulator; 5-second circulator; 6-sensing module; 7-first fiber polarization controller; 8-second fiber polarization controller; 9-post-selection module; 10-spectrometer; 11-first fiber beam splitter; 12-beam splitter; 13-first phase compensator; 14-second phase compensator; 15-second polarizer; 16-third polarizer; 17-first fiber collimator; 18-second fiber collimator; 19-second fiber beam splitter. Detailed Implementation

[0033] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0034] Example 1 A high-precision temperature and pressure measuring device provided by the present invention, such as Figure 1 As shown, it includes: Broadband light source 1, front selection module, sensing module 6, first fiber polarization controller 7, second fiber polarization controller 8, rear selection module 9; The broadband light source 1 is used to acquire broadband light that meets preset requirements; The pre-selection module is used to preprocess the acquired broadband light to obtain preprocessed broadband light. The sensing module 6 is used to sense changes in ambient temperature and pressure based on pre-processed broadband light and fiber optic grating. The first fiber polarization controller 7 and the second fiber polarization controller 8 are used to adjust the polarization state of the reflected beam of the sensing module 6. The post-selection module 9 and the spectrometer 10 are used to measure temperature and pressure based on the adjusted reflected beam.

[0035] The pre-selection module includes: a first polarizer 2, a polarization beam splitter 3, a first circulator 4, and a second circulator 5; The first polarizer 2 is used to modulate the acquired broadband light into initial state light; The polarization beam splitter 3 is used to separate the initial state light into horizontally polarized light and vertically polarized light; The horizontally polarized light sequentially passes through the second circulator 5, the sensing module 6, and the second fiber polarization controller 8 to form a second optical path channel; the second optical path channel is used to propagate and adjust the horizontally polarized light. The vertically polarized light sequentially passes through the first circulator 4, the sensing module 6, and the first fiber polarization controller 7 to form a first optical path channel; the first optical path channel is used to propagate and adjust the vertically polarized light.

[0036] More specifically, the broadband light source 1 is connected to the first polarizer 2; the first polarizer 2 is connected to the polarization beam splitter 3; the polarization beam splitter 3 is connected to the first circulator 4 and the second circulator 5 respectively; the second circulator 4 is connected to the sensing module 6 and the first fiber polarization controller 7 respectively; the second circulator 5 is connected to the sensing module 6 and the second fiber polarization controller 8 respectively; the first fiber polarization controller 7 and the second fiber polarization controller 8 are connected to the post-selection module 9, and the post-selection module 9 is connected to the spectrometer 10.

[0037] like Figure 6 As shown, the subsequent selection module 9 includes a first fiber optic beam splitter 11, a beam splitter 12, a first phase compensator 13, a second phase compensator 14, a second polarizer 15, a third polarizer 16, a first fiber optic collimator 17, a second fiber optic collimator 18, and a second fiber optic beam splitter 19. The first fiber beam splitter 11 is connected to the beam splitter 12; the beam splitter 12 is connected to the first phase compensator 13 and the second phase compensator 14 respectively; the first phase compensator 13 is connected to the second polarizer 15; the second polarizer 15 is connected to the first fiber collimator 17; the second phase compensator 14 is connected to the third polarizer 16; the third polarizer 16 is connected to the second fiber collimator 18; the first fiber collimator 17, the second fiber collimator 18 and the second fiber beam splitter 19 are connected.

[0038] The sensing module 6 includes a spherical device for fixing the position of the fiber Bragg grating, such as... Figure 2 As shown, there are two enclosed air chambers, the first enclosed air chamber and the second enclosed air chamber. The surface of the spherical device can be divided into four regions Q1, Q2, Q3, and Q4, and a first fiber grating, a second fiber grating, a third fiber grating, and a fourth fiber grating are respectively attached to the surface of each region.

[0039] The horizontally polarized light split by the polarization beam splitter |H Connected to the first fiber grating, the second fiber grating, and the second circulator 5, its path is denoted as channel 2; the vertically polarized beam |V It is connected to the third fiber grating, the fourth fiber grating, and the first circulator 4, and its path is denoted as channel 1.

[0040] Example 2 Example 2 is a preferred example of Example 1. The present invention provides a high-precision temperature and pressure measurement method that utilizes the characteristic that the center wavelength of the fiber optic grating reflection spectrum is affected by temperature and pressure, and incorporates temperature compensation and differential compensation for vibration interference. Finally, it uses weak measurement to extract pressure and temperature values ​​with high precision. The method includes the following steps: step S1 spectral emission, step S2 pre-selection process, step S3 sensing process, and step S4 post-selection process and measurement process.

[0041] Step S1 includes: the output beam of the broadband light source 1 must have a full width at half maximum (FWHM) greater than the center wavelength of the four fiber optic gratings and within the FWHM spectral range.

[0042] Specifically, step S2 includes: The emitted broadband light is modulated to its initial state after passing through the first polarizer 2, including:

[0043] The initial light is incident on the polarization beam splitter 3, which separates the incident light into horizontally polarized light. and vertically polarized light They are coupled to channel 2 and channel 1 respectively.

[0044] The first circulator 4 and the second circulator 5 transmit horizontally polarized light and vertically polarized light to the sensing module.

[0045] Specifically, step S3 includes: like Figure 2 As shown, sensing module 6 is a spherical device containing a first fiber optic grating, a second fiber optic grating, a third fiber optic grating, a fourth fiber optic grating, and connecting optical fibers. The first and third fiber optic gratings are temperature sensing gratings. All fiber optic gratings and their optical paths are mounted around the spherical device housing. The two fiber optic gratings of the temperature sensing grating are mounted at positions Q1 and Q3 on the spherical device housing, while the two fiber optic gratings of the pressure sensing grating are mounted at elastic diaphragms Q2 and Q4 on the two sides of the device. The solid spherical housing is a sealed structure with a closed air cavity at the center. The diaphragms at both ends deform under external pressure, which includes the static pressure of the measurement environment and vibration interference within the environment.

[0046] The angular frequency of the reflected light from the fiber grating should satisfy the following formula under the influence of temperature and pressure. = +

[0047] in , corresponding to fiber gratings 1, 2, 3, and 4. The center angular frequency of the initial reflection spectrum of the fiber grating. This represents the change in angular frequency. For temperature sensitivity coefficient, This refers to the change in temperature. The pressure sensitivity coefficient, This is the change in static pressure; This represents the vibrational change. Under conditions of no temperature or pressure, the reflection spectra of fiber gratings 1 and 3 are identical, i.e. = = The fiber gratings 2 and 4 have the same reflection spectrum, that is... = = .

[0048] Since fiber grating 1 and fiber grating 3 are fixed at Q1 and Q3, it can be assumed that the strain of fiber grating 1 and fiber grating 3 is only affected by temperature, i.e., pressure coefficient: , Furthermore, the center angular frequency offset of the reflected light from fiber grating 1 and fiber grating 3 only reflects temperature information: ≈ *

[0049] ≈ *

[0050] Adding the two equations together and taking the average can reduce measurement error. * =

[0051] like Figure 3 As shown, the deformation of the diaphragm is determined by the absolute value of the pressure difference between the inside and outside.

[0052] The sealed air chamber 1 is under high pressure, with a pressure of P1, and the sealed air chamber 2 is under negative pressure, with a static pressure Ps satisfying the range P2. <Ps<P1。

[0053] like Figure 4 As shown, due to the existence of positive and negative pressure differences, the deformation of the diaphragm caused by the same static pressure is opposite, and consequently, the strain caused by the fiber grating is an opposite pair. The decrease in strain of fiber grating 2 is equal to the increase in strain of fiber grating 4. Therefore: .

[0054] like Figure 5 As shown, the pressure sensed by the diaphragm is actually influenced by both the static pressure of the seawater and the vibration interference within the seawater. The vibration interference is a parameter of equal magnitude and direction, and its force is much smaller than that of the static pressure. The static pressure determines the direction of the diaphragm's deformation. At this point, the strain caused by the vibration interference to the fiber grating is exactly the same. Therefore: .

[0055] The results of integration are as follows: = -

[0056] = +

[0057] Subtracting the two equations yields the relation:

[0058] in This represents the magnitude of static pressure. Because...

[0059] Therefore:

[0060] Specifically, step S4 includes: The light reflected from the four fiber gratings is collected by the circulator after propagation backward. The fiber polarization controller 7 is then adjusted so that the probe beam propagating through the second optical path channel before reaching the post-selection module 9 is... Adjust the fiber polarization controller 8 so that the detection beam propagating through the first optical path channel to the post-selection module 9 is After entering the selection process 9, the fiber optic beam splitter 11 first combines the light from the same sensing group for weak measurements. From step S2, the previous selection state is...

[0061] For fiber gratings 1 and 3 in the temperature sensing group, the state after bundle combination is:

[0062] in, .

[0063] For the pressure sensing group, fiber gratings 2 and 4, the combined state is:

[0064] in, The center angular frequency of fiber Bragg gratings 2 and 4 after they are combined. .

[0065] in, is the spectral distribution function of the fiber grating reflection.

[0066] The light reflected from the four fiber Bragg gratings is combined and then split into two paths by beam splitter 12. The selected state after splitting into two paths is... β is the post-selection angle, representing the transmission axis angles of polarizers 15 and 16, respectively, with the following spectral distributions:

[0067]

[0068] in, , The phase difference between the same type of fiber gratings in the first and second optical path channels. The phase compensation for the phase shifter is controlled by phase compensators 13 and 14 respectively.

[0069] After two-way selection, the fiber collimators 17 and 18 couple the fiber into an optical fiber, then the fiber is combined through 19. Spectral analysis is performed by spectrometer 10, and the average spectral shift is calculated to be:

[0070]

[0071] The magnitudes of the two weak values ​​represent the amplification factor for the spectral frequency shift:

[0072] Therefore, through calculation, we can obtain...

[0073] .

[0074] The present invention also provides a high-precision temperature and pressure measurement system, which can be implemented by executing the process steps of the high-precision temperature and pressure measurement method. That is, those skilled in the art can understand the high-precision temperature and pressure measurement method as a preferred embodiment of the high-precision temperature and pressure measurement system.

[0075] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0076] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A high-precision temperature and pressure measuring device, characterized in that, include: A broadband light source (1), a front selection module, a sensing module (6), a first fiber polarization controller (7), a second fiber polarization controller (8), a back selection module (9), and a spectrometer (10). The broadband light source (1) is used to obtain broadband light that meets preset requirements; The pre-selection module is used to preprocess the acquired broadband light to obtain preprocessed broadband light. The sensing module (6) is used to sense the changes in ambient temperature and pressure based on the pre-processed broadband light and fiber optic grating. The first fiber polarization controller (7) and the second fiber polarization controller (8) are used to adjust the polarization state of the reflected beam of the sensing module (6); The post-selection module (9) and the spectrometer (10) are used to measure temperature and pressure based on the adjusted reflected beam.

2. The high-precision temperature and pressure measuring device according to claim 1, characterized in that, The pre-selection module includes: a first polarizer (2), a polarization beam splitter (3), a first circulator (4), and a second circulator (5); The first polarizer (2) is used to modulate the acquired broadband light into initial state light; The polarization beam splitter (3) is used to separate the initial state light into horizontally polarized light and vertically polarized light; The horizontally polarized light sequentially passes through the second circulator (5), the sensing module (6), and the second fiber polarization controller (8) to form a second optical path channel; the second optical path channel is used to propagate and adjust the horizontally polarized light. The vertically polarized light sequentially passes through the first circulator (4), the sensing module (6), and the first fiber polarization controller (7) to form a first optical path channel; the first optical path channel is used to propagate and adjust the vertically polarized light.

3. The high-precision temperature and pressure measuring device according to claim 2, characterized in that, The broadband light source (1) is connected to the first polarizer (2); the first polarizer (2) is connected to the polarization beam splitter (3); the polarization beam splitter (3) is connected to the first circulator (4) and the second circulator (5) respectively; the second circulator (4) is connected to the sensing module (6) and the first fiber polarization controller (7) respectively; the second circulator (5) is connected to the sensing module (6) and the second fiber polarization controller (8) respectively; the first fiber polarization controller (7) and the second fiber polarization controller (8) are connected to the post-selection module (9), and the post-selection module (9) is connected to the spectrometer (10).

4. The high-precision temperature and pressure measuring device according to claim 2, characterized in that, The sensing module (6) is a spherical device used to fix the position of the fiber optic grating; The surface of the spherical device is divided into a first region Q1, a second region Q2, a third region Q3, and a fourth region Q4; a first fiber grating, a second fiber grating, a third fiber grating, and a fourth fiber grating are respectively attached to the surface of the regions; The horizontally polarized light is connected to the second circulator (5), the first fiber optic grating, and the second fiber optic grating to form a second optical path channel; The vertically polarized light is connected to the first circulator (4), the third fiber grating, and the fourth fiber grating to form a first optical path channel; The first and third fiber gratings form a temperature sensing group; the second and fourth fiber gratings form a pressure sensing group, and the second and fourth fiber gratings are mounted on elastic diaphragms in the second region Q2 and the fourth region Q4; the elastic diaphragms deform under external pressure in the closed air chamber structure to amplify the pressure strain; wherein the external pressure includes the static pressure of the measurement environment and vibration interference within the environment.

5. The high-precision temperature and pressure measuring device according to claim 1, characterized in that, The post-selection module (9) includes: a first fiber beam splitter (11), a beam splitter (12), a first phase compensator (13), a second phase compensator (14), a second polarizer (15), a third polarizer (16), a first fiber collimator (17), a second fiber collimator (18), and a second fiber beam splitter (19). The first fiber beam splitter (11) is connected to the beam splitter (12); the beam splitter (12) is connected to the first phase compensator (13) and the second phase compensator (14) respectively; the first phase compensator (13) is connected to the second polarizer (15); the second polarizer (15) is connected to the first fiber collimator (17); the second phase compensator (14) is connected to the third polarizer (16); the third polarizer (16) is connected to the second fiber collimator (18); the first fiber collimator (17), the second fiber collimator (18) and the second fiber beam splitter (19) are connected.

6. A high-precision method for measuring temperature and pressure, characterized in that, Based on the high-precision temperature and pressure measuring device according to any one of claims 1 to 5, the following steps are performed: Step S1: Obtain broadband light that meets the preset requirements through a broadband light source (1); Step S2: Broad-spectrum light that meets the preset requirements passes through the pre-selection module to obtain horizontally polarized light and vertically polarized light; Step S3: The sensing module (6) senses the changes in ambient temperature and pressure based on horizontally polarized light and vertically polarized light; Step S4: Adjust the polarization state of the reflected beam of the sensing module (6) using the first fiber polarization controller (7) and the second fiber polarization controller (8); Step S5: The next selection module (9) measures the temperature and pressure based on the adjusted reflected beam.

7. The high-precision temperature and pressure measurement method according to claim 6, characterized in that, Step S1 includes: acquiring broadband light that meets preset requirements based on a preset spectral frequency using a broadband light source; wherein, the wavelength range corresponding to the full width at half maximum (FWHM) of the broadband light that meets the preset requirements at the center wavelength must completely cover the reflection spectrum of the fiber grating. The fiber gratings of the temperature sensing group and the pressure sensing group have the same reflection spectrum; and the reflection spectra of the fiber gratings of the temperature and pressure sensing groups have a large spectral interval.

8. The high-precision temperature and pressure measurement method according to claim 5, characterized in that, Step S2 includes: Step S2.1: Modulate the acquired broadband light into initial state light using the first polarizer (2); Step S2.2: The initial state light is separated into horizontally polarized light and vertically polarized light by a polarization beam splitter (3); Step S2.3: Horizontally polarized light sequentially passes through the second circulator (5), the sensing module (6), and the second fiber polarization controller (8) to form a second optical path channel; the second optical path channel is used to propagate and adjust the horizontally polarized light; Step S2.4: Vertically polarized light passes through the first circulator (4), the sensing module (6), and the first fiber polarization controller (7) in sequence to form a first optical path channel; the first optical path channel is used to propagate and adjust vertically polarized light.

9. The high-precision temperature and pressure measurement method according to claim 5, characterized in that, Step S4 includes: After the horizontally polarized light is adjusted by the second fiber polarization controller (8), the adjusted horizontally polarized light is obtained. ; After the vertically polarized light is adjusted by the first fiber polarization controller (7), the adjusted horizontally polarized light is obtained. .

10. The high-precision temperature and pressure measurement method according to claim 5, characterized in that, Step S5 includes: adjusted horizontally polarized light And adjusted horizontally polarized light The light from the same sensing group is combined by the first fiber optic beam splitter (11). The state after combining temperature sensing elements is: in, The center angular frequency of the fiber grating after bundle combining. ; The change in temperature Temperature coefficient; This is the adjusted horizontally polarized light; This is the adjusted vertically polarized light; The imaginary unit, The phase difference of the fiber gratings between the temperature sensing groups of channel one and channel two; The fiber grating reflection spectral distribution function; The state after the pressure sensing assembly is: in, The center angular frequency of the fiber grating after bundle combining. ; The pressure sensitivity coefficient, The change in vibration The imaginary unit, The phase difference of the fiber gratings in the pressure sensing groups of channel one and channel two; The light reflected from the four fiber gratings is combined and then split into two beams by a beam splitter (12); the two-way selection state is... , β The angles selected later represent the transmission axis angles of the second polarizer (15) and the third polarizer (16), respectively; Spectral distribution in, , The phase difference of the same set of fiber gratings The phase compensation for the phase shifter is controlled by the first phase compensator (13) and the second phase compensator (14), respectively; These are the reflection spectral linewidths of the fiber Bragg gratings for the temperature and pressure sensing groups, respectively. After two-way selection, the fibers are coupled into an optical fiber via the first optical fiber collimator (17) and the first optical fiber collimator (18), and then combined via the second optical fiber bundle splitter (19). Spectral analysis is performed using a spectrometer (10). The average spectral frequency shift is calculated to be... The magnitudes of the two weak values ​​represent the amplification factor for the spectral frequency shift: Therefore, through calculation, we can obtain... 。

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