Temperature-pressure composite calibration device and method for optical fiber high-temperature pressure sensor

Abstract

The invention discloses a temperature and pressure composite calibration device and method for an optical fiber high-temperature pressure sensor. The device comprises an outer cavity, an inner cavity, a heating module, a heat preservation layer, a thermocouple, a water cooling pipe, a cavity cover, a cabin penetrating piece, a standard pressure sensor, a vacuum system, a high-purity argon bottle and a temperature controller. The outer cavity, the inner cavity and the cavity cover form a pressure cavity; the heat preservation layer is arranged on the heating module and located in the inner cavity. The thermocouple and the high-temperature probe are respectively arranged in different through holes in the thermal insulation layer; the water cooling pipe is mounted outside the outer cavity; the cabin penetrating piece is hermetically connected with the cavity cover; the side wall of the outer cavity is provided with a high-pressure gas inlet used for being connected with a high-purity argon bottle, a vacuum extraction opening used for being connected with a vacuum system, a pressure detection opening used for installing a standard pressure sensor, a temperature controller connector used for being connected with a temperature controller and an exhaust port. The temperature and pressure composite calibration problem of the optical fiber high-temperature pressure sensor is solved, and a new means is provided for development and measurement of the optical fiber high-temperature pressure sensor.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic sensor testing technology, and particularly relates to a temperature and pressure composite calibration device and method for fiber optic high-temperature pressure sensors. Background Technology

[0002] In recent years, fiber optic sensing technology, with its inherent safety, resistance to electromagnetic interference, and the high melting point potential of quartz glass, has provided a new approach to measuring high-temperature and high-pressure conditions in extreme environments. However, research on fiber optic high-temperature and high-pressure sensors started relatively late in China, and the technological barriers are high. Currently, related technologies in China are not yet fully mature, thus limiting their widespread application. Among these challenges, calibration technology under high-temperature and high-pressure environments is one of the key bottlenecks restricting the development of fiber optic high-temperature and high-pressure sensors. Therefore, it is urgent to solve the "inaccuracy" problem of fiber optic high-temperature and high-pressure sensors. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a temperature-pressure composite calibration device and method for fiber optic high-temperature pressure sensors, which solves the temperature-pressure composite calibration problem of fiber optic high-temperature pressure sensors and provides a new means for the development and measurement of fiber optic high-temperature pressure sensors.

[0004] To address the aforementioned technical problems, this invention discloses a temperature-pressure composite calibration device for an optical fiber high-temperature pressure sensor, comprising: an outer cavity, an inner cavity, a heating module, an insulation layer, a thermocouple, a water-cooling pipe, a cavity cover, a transom component, a standard pressure sensor, a vacuum system, a high-purity argon cylinder, and a temperature controller; wherein, one end of the outer cavity is connected to the cavity cover, and the other end is connected to the inner cavity; the outer cavity, the inner cavity, and the cavity cover together form a closed pressure chamber; the heating module and the insulation layer are located in the inner cavity, with the insulation layer disposed on the heating module; the insulation layer has a through hole A and at least one through hole B, the bottoms of both through holes A and B being attached to the heating module; the thermocouple is placed in through hole A and attached to the heating module; at least one high-temperature probe of the optical fiber high-temperature pressure sensor under test is placed in the corresponding... Inside through-hole B, it fits snugly against the heating module; a water-cooling pipe is installed on the outside of the outer cavity; a through-hole component is located in the middle of the cavity cover and is sealed to the cavity cover; the pigtail of at least one fiber optic high-temperature pressure sensor under test is led out to the outside of the pressure chamber through the through-hole component; a high-pressure gas inlet, an exhaust outlet, a vacuum extraction outlet, a pressure detection port, and a temperature controller interface are provided on the side wall of the outer cavity; a high-purity argon cylinder is connected to the high-pressure gas inlet through connecting pipe A; the vacuum system is connected to the vacuum extraction port through connecting pipe B; a standard pressure sensor is installed at the pressure detection port; the temperature controller is connected to the heating module and the thermocouple respectively through wires; the temperature controller is located on the outside of the pressure chamber, one end of the temperature controller is connected to the wire, and the other end of the wire passes through the temperature controller interface and is connected to the heating module and the thermocouple respectively.

[0005] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, one end of the outer cavity is fixed to the cavity cover by screws and sealed by a polytetrafluoroethylene gasket; wherein, the screws are evenly and symmetrically distributed on the outside of the cavity cover.

[0006] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, the heating module generates local high temperature through electric heating, and the surrounding area is maintained at high temperature by an insulation layer.

[0007] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, the temperature controller, heating module, and thermocouple form a temperature control system for displaying and controlling the temperature of the insulation zone; where the insulation zone refers to the area where the insulation layer is located.

[0008] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, the outer cavity sidewall has a double-layer structure, and the water-cooling pipe is installed inside the double-layer structure. The water-cooling pipe cools the outer cavity by connecting to a water chiller, creating a low-temperature zone, so that the entire pressure cavity forms a temperature gradient zone of inner cavity heating and outer cavity water cooling.

[0009] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, the through-hole component is an optical flange connector, which is fixed to the center of the cavity cover by means of threads and washers, so as to achieve a sealed connection between the through-hole component and the cavity cover.

[0010] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, a high-purity argon gas cylinder is introduced into the pressure chamber through a high-pressure gas inlet to adjust the internal pressure of the pressure chamber; at the same time, the high-purity argon gas, as a protective gas, can provide anti-oxidation protection for the fiber optic high-temperature pressure sensor under test at high temperatures.

[0011] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, a vacuum system is used to evacuate the pressure chamber.

[0012] In the aforementioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device, a standard pressure sensor is used to monitor the internal pressure of the pressure chamber.

[0013] Accordingly, this invention also discloses a temperature-pressure composite calibration method for fiber optic high-temperature pressure sensors, comprising: S1. Open the cavity cover and place the high-temperature probe of the fiber optic high-temperature pressure sensor under test into the through hole B of the insulation layer, ensuring that the high-temperature probe and the thermocouple are in the same plane. S2, the pigtail of the fiber optic high-temperature pressure sensor under test is led out from the chamber fitting, and the cavity cover is sealed to the outer cavity by screws and PTFE gaskets. S3, activate the vacuum system to evacuate the inside of the pressure chamber to a vacuum; S4. Connect the water cooling pipe to the water chiller, turn on the water chiller, and cool the external cavity through the water cooling pipe to form a temperature gradient range. S5, based on the current calibration temperature point, controls the heating module to work through the temperature controller, adjusting the temperature of the insulation zone to the current calibration temperature point; after the temperature of the insulation zone reaches the current calibration temperature point, it maintains the temperature for a period of time; S6, open the high-purity argon cylinder, observe the pressure reading of the standard pressure sensor, and perform pressure calibration at the current calibration temperature point according to the calibration pressure point; S7. After the pressure stroke test at the current calibration temperature point is completed, repeat the above steps S3~S6 to perform pressure calibration at the next calibration temperature point. S8, based on the readings of the thermocouple and the standard pressure sensor, uses a comparative calibration method to complete the temperature and pressure composite calibration test of the fiber optic high-temperature pressure sensor under test.

[0014] The present invention has the following advantages: (1) This invention discloses a temperature and pressure composite calibration device for an optical fiber high temperature pressure sensor. It designs a high-strength, closed pressure chamber and installs the entire optical fiber high temperature pressure sensor in the pressure chamber. This avoids the leakage of high temperature and high pressure gas caused by improper installation of the high temperature probe of the optical fiber high temperature pressure sensor and the pressure testing fixture, thus improving the test safety. At the same time, the pigtail of the optical fiber high temperature pressure sensor is led out to the outside of the pressure chamber through the sealed optical penetration component, thereby realizing the penetration sealing of the optical fiber high temperature pressure sensor.

[0015] (2) The present invention discloses a temperature-pressure composite calibration device for an optical fiber high temperature pressure sensor. It uses internal cavity heating and external cavity water cooling to create a temperature gradient in the pressure cavity. While providing a high temperature environment for the high temperature probe of the optical fiber high temperature pressure sensor, it reduces the temperature of the pigtail of the optical fiber high temperature pressure sensor, protecting the pigtail from the effects of high temperature on encapsulation failure and signal loss. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the installation of a fiber optic high-temperature pressure sensor in a temperature and pressure composite calibration device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the temperature and pressure calibration curve of an optical fiber high-temperature pressure sensor in an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0018] Reference Figure 1 In this embodiment, the fiber optic high-temperature pressure sensor temperature-pressure composite calibration device includes: an outer cavity 1, an inner cavity 2, a heating module 3, an insulation layer 4, a thermocouple 6, a water-cooling pipe 7, a cavity cover 8, a chamber penetration component 9, a vacuum system 14, a high-purity argon cylinder 15, and a temperature controller 17; wherein, one end of the outer cavity 1 is connected to the cavity cover 8, and the other end is connected to the inner cavity 2; the outer cavity 1, the inner cavity 2, and the cavity cover 8 together form a closed pressure chamber; the heating module 3 and the insulation layer 4 are located in the inner cavity 2, and the insulation layer 4 is disposed on the heating module 3; the insulation layer 4 has a through hole A51 and at least one through hole B52, and the bottom of the through hole A51 and the through hole B52 are attached to the heating module 3; the thermocouple 6 is placed in the through hole A51 and is attached to the heating module 3; at least one high-temperature probe of the fiber optic high-temperature pressure sensor under test is placed in the corresponding through hole B52 and is attached to the heating module. 3. Fitting; Water-cooled pipe 7 is installed on the outside of outer cavity 1; Through-cavity component 9 is set in the middle of cavity cover 8 and sealed to cavity cover 8; The pigtail of at least one fiber optic high-temperature pressure sensor under test is led out to the outside of pressure cavity through through-cavity component 9; High-pressure gas inlet 10, exhaust port 11, vacuum pump port 12, pressure detection port 18 and temperature controller interface 16 are provided on the side wall of outer cavity 1; High-purity argon cylinder 15 is connected to high-pressure gas inlet 10 through connecting pipe A; Vacuum system 14 is connected to vacuum pump port 12 through connecting pipe B; Standard pressure sensor 13 is installed at pressure detection port 18; Temperature controller 17 is connected to heating module 3 and thermocouple 6 through wires respectively; Temperature controller 17 is located outside pressure cavity, one end of temperature controller 17 is connected to wire, and the other end of wire passes through temperature controller interface 16 and is connected to heating module 3 and thermocouple 6 respectively.

[0019] In this embodiment, one end of the outer cavity 1 is fixed to the cavity cover 8 by screws, and a polytetrafluoroethylene gasket is used to achieve a seal. The screws are evenly and symmetrically distributed on the outside of the cavity cover 8.

[0020] In this embodiment, the heating module 3 generates local high temperature through electric heating, and the surrounding heat insulation layer 4 maintains the high temperature.

[0021] In this embodiment, the temperature controller 17, the heating module 3, and the thermocouple 6 form a temperature control system for displaying and controlling the temperature of the insulation zone (the area where the insulation layer is located). The heating module 3 is a graphite heater; the insulation layer 4 is made of alumina fiber and graphite felt; and the thermocouple 6 is a platinum-rhodium thermocouple or a tungsten-rhenium thermocouple used to measure the temperature of the insulation zone.

[0022] In this embodiment, the sidewall of the outer cavity 1 has a double-layer structure, and the water-cooling pipe 7 is installed inside the double-layer structure. The water-cooling pipe 7 cools the outer cavity 1 by connecting to a water chiller, creating a low-temperature zone, so that the entire pressure cavity forms a temperature gradient zone where the inner cavity 2 is heated and the outer cavity 1 is cooled by water.

[0023] In this embodiment, the through-hole component 9 is an optical flange connector, which is fixed to the center of the cavity cover 8 by means of threads and washers, so as to achieve a sealed connection between the through-hole component 9 and the cavity cover 8.

[0024] In this embodiment, high-purity argon gas is introduced into the pressure chamber through the high-pressure gas inlet 10 from the high-pressure gas cylinder 15 to regulate the internal pressure of the pressure chamber. Simultaneously, the high-purity argon gas acts as a protective gas to provide anti-oxidation protection for the fiber optic high-temperature pressure sensor under test at high temperatures. The pressure of the high-pressure gas output from the high-purity argon cylinder 15 can be adjusted using a pressure reducing gauge, and the flow rate of the high-pressure gas output from the high-purity argon cylinder 15 can be controlled by a manual valve.

[0025] In this embodiment, the vacuum system 14 is used to evacuate the pressure chamber. The vacuum system 14 includes a mechanical pump and a molecular pump, which are used to achieve the evacuation process.

[0026] In this embodiment, a standard pressure sensor 13 is used to monitor the internal pressure of the pressure chamber.

[0027] In this embodiment, the outer cavity 1, the inner cavity 2, and the cavity cover 8 are made of high-strength special steel.

[0028] In summary, this invention discloses a temperature-pressure composite calibration device for fiber optic high-temperature pressure sensors, providing a high-temperature and high-pressure calibration test environment for these sensors, while also enabling data display and control of the test environment. The device uses high-strength special steel as the pressure chamber, creating a temperature gradient within the chamber through internal heating and external water cooling. The fiber optic cable is led out using a chamber cover and a through-hole component, ensuring both signal transmission and the airtightness of the pressure chamber. The pressure environment within the chamber is altered by setting a high-pressure gas inlet, outlet, and vacuum outlet on the outside of the outer cavity. Under high-temperature vacuum or high-temperature and high-pressure conditions, the fiber optic high-temperature pressure sensor is calibrated using a temperature-pressure composite method by precisely controlling temperature and pressure.

[0029] In this embodiment, the temperature-pressure composite calibration method based on the above-mentioned fiber optic high-temperature pressure sensor temperature-pressure composite calibration device is as follows: S1. Open the cavity cover 8 and place the high-temperature probe of the fiber optic high-temperature pressure sensor under test into the through hole B52 of the insulation layer 4, ensuring that the high-temperature probe and the thermocouple 6 are in the same plane.

[0030] S2, the pigtail of the fiber optic high-temperature pressure sensor under test is led out from the chamber 9, and the cavity cover 8 is sealed to the outer cavity 1 by screws and PTFE gaskets.

[0031] S3, activate vacuum system 14 to evacuate the inside of the pressure chamber to a vacuum (≤10Pa).

[0032] S4. Connect the water cooling pipe 7 to the water chiller, turn on the water chiller, and cool the outer cavity 1 through the water cooling pipe 7 to form a temperature gradient range.

[0033] S5, based on the current calibration temperature point, control the heating module 3 to work through the temperature controller 17, and adjust the temperature of the insulation zone to the current calibration temperature point; after the temperature of the insulation zone reaches the current calibration temperature point, keep it warm for a period of time (not less than 1 hour).

[0034] S6, open the high-purity argon cylinder 15, observe the pressure reading of the standard pressure sensor 13, and perform pressure calibration at the current calibration temperature point according to the calibration pressure point.

[0035] S7. After the pressure stroke test at the current calibration temperature point is completed, repeat steps S3 to S6 above to perform pressure calibration at the next calibration temperature point.

[0036] S8. Based on the readings of thermocouple 6 and standard pressure sensor 13, a comparative calibration method is used to complete the temperature and pressure composite calibration test of the fiber optic high-temperature pressure sensor under test.

[0037] Based on the above embodiments, the following is a specific example of composite calibration.

[0038] The composite calibration process for a certain fiber optic high-temperature pressure sensor under test is as follows: Open the cavity cover 8 and remove the fiber optic high-temperature pressure sensor under test from the product box. Insert the high-temperature probe of the fiber optic high-temperature pressure sensor from the outer cavity 1 into the inner cavity 2. Locate the through-hole B in the insulation area and place the high-temperature probe of the fiber optic high-temperature pressure sensor into the through-hole B52, ensuring that the high-temperature probe and thermocouple 6 are on the same plane. Insert high-temperature cotton into the outside of the through-hole B52 to fix and insulate the high-temperature probe. Extend the pigtail of the fiber optic high-temperature pressure sensor from the inner cavity 2 to the outer cavity 1, connecting it to the optical interface of the through-hole component 9 at the center of the cavity cover 8, and maintaining signal communication with the optical cable outside the through-hole component 9. Figure 2 As shown. Place the PTFE gasket at the cavity cover opening, and fix the cavity cover 8 to the outer cavity 1 with screws. During this operation, the screws should be tightened symmetrically so that the PTFE gasket is in contact with the outer cavity 1 and the cavity cover 8, in order to keep the entire pressure chamber sealed.

[0039] Close the valves of the high-pressure gas inlet 10 and outlet 11, and open the valve of the vacuum pumping port 12; turn on the vacuum system 14, and use the mechanical pump and molecular pump of the vacuum system 14 to pump air into the pressure chamber. The standard pressure sensor 13 displays the real-time pressure inside the pressure chamber. When the pressure inside the pressure chamber is pumped to a vacuum (≤10Pa), close the valve of the vacuum pumping port 12 and shut down the vacuum system 14.

[0040] Connect the water-cooling pipe 7 to the water chiller, turn on the water chiller, and cool the outer cavity 1 through the water-cooling pipe 7 to form a temperature gradient range.

[0041] The temperature rise curve is set by the temperature controller 17. Multiple temperature points are set according to the calibration temperature point. After reaching each temperature point, it is necessary to keep it warm for a period of time (not less than 1 hour). Pressure calibration is started after the temperature stabilizes.

[0042] By adjusting the valves of the high-pressure gas inlet 10, the exhaust port 11, and the vacuum extraction port 12, observe the pressure reading of the standard pressure sensor 13, and perform forward and reverse stroke temperature and pressure composite calibration according to the calibration pressure point.

[0043] After the pressure stroke test at the current calibration temperature point is completed, open the valve of the vacuum extraction port 12, turn on the vacuum system 14, and draw the internal pressure of the pressure chamber to a vacuum (≤10Pa). After the temperature control system heats up and maintains the temperature, perform pressure calibration at the next calibration temperature point. Based on the readings of thermocouple 6 and standard pressure sensor 13, a comparative calibration method was used to complete the temperature-pressure composite calibration test of the fiber optic high-temperature pressure sensor under test. Figure 3 As shown.

[0044] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0045] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A temperature-pressure composite calibration device for an optical fiber high-temperature pressure sensor, characterized in that, include: The structure consists of an outer cavity (1), an inner cavity (2), a heating module (3), an insulation layer (4), a thermocouple (6), a water-cooled pipe (7), a cavity cover (8), a transom component (9), a standard pressure sensor (13), a vacuum system (14), a high-purity argon cylinder (15), and a temperature controller (17). One end of the outer cavity (1) is connected to the cavity cover (8), and the other end is connected to the inner cavity (2). The outer cavity (1), inner cavity (2), and cavity cover (8) together form a closed pressure chamber. The heating module (3) and insulation layer... Layer (4) is located in the inner cavity (2), and the insulation layer (4) is disposed on the heating module (3); the insulation layer (4) has a through hole A (51) and at least one through hole B (52), and the bottom of the through hole A (51) and the through hole B (52) are attached to the heating module (3); the thermocouple (6) is placed in the through hole A (51) and attached to the heating module (3); at least one high temperature probe of the fiber optic high temperature pressure sensor under test is placed in the corresponding through hole B (52) and attached to the heating module (3). The water-cooled pipe (7) is installed on the outside of the outer cavity (1); the chamber-penetrating component (9) is located in the middle of the cavity cover (8) and is sealed to the cavity cover (8); the pigtail of at least one fiber optic high-temperature pressure sensor under test is led out to the outside of the pressure chamber through the chamber-penetrating component (9); the side wall of the outer cavity (1) is provided with a high-pressure gas inlet (10), an exhaust port (11), a vacuum pumping port (12), a pressure detection port (18) and a temperature controller interface (16); the high-purity argon cylinder (15) is connected to the high-pressure gas via connecting pipe A. The air inlet (10) is connected; the vacuum system (14) is connected to the vacuum pumping port (12) through the connecting pipe B; the standard pressure sensor (13) is installed at the pressure detection port (18); the temperature controller (17) is connected to the heating module (3) and the thermocouple (6) respectively through the wires; the temperature controller (17) is located outside the pressure chamber, and one end of the temperature controller (17) is connected to the wire, and the other end of the wire passes through the temperature controller interface (16) and is connected to the heating module (3) and the thermocouple (6) respectively.

2. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, One end of the outer cavity (1) is fixed to the cavity cover (8) by screws and sealed by a polytetrafluoroethylene gasket; wherein the screws are evenly and symmetrically distributed on the outside of the cavity cover (8).

3. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, The heating module (3) generates local high temperature through electric heating, and the surrounding area is maintained at high temperature by the insulation layer (4).

4. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, The temperature controller (17), together with the heating module (3) and the thermocouple (6), forms a temperature control system for displaying and controlling the temperature of the insulation zone; where the insulation zone refers to the area where the insulation layer (4) is located.

5. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, The outer cavity (1) has a double-layer structure on its side wall, and the water-cooling pipe (7) is installed inside the double-layer structure. The water-cooling pipe (7) is connected to a water chiller to cool the outer cavity (1) and create a low-temperature zone, so that the entire pressure cavity forms a temperature gradient zone where the inner cavity (2) is heated and the outer cavity (1) is cooled by water.

6. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, The through-hole component (9) is an optical flange connector, which is fixed to the center of the cavity cover (8) by means of thread and gasket, so as to achieve a sealed connection between the through-hole component (9) and the cavity cover (8).

7. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, High-purity argon gas cylinder (15) introduces high-purity argon gas into the pressure chamber through high-pressure gas inlet (10) to regulate the internal pressure of the pressure chamber; at the same time, high-purity argon gas, as a protective gas, can provide anti-oxidation protection for the fiber optic high-temperature pressure sensor under test at high temperature.

8. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, Vacuum system (14) is used to evacuate the pressure chamber.

9. The fiber optic high-temperature pressure sensor temperature-pressure composite calibration device according to claim 1, characterized in that, A standard pressure sensor (13) is used to monitor the internal pressure of the pressure chamber.

10. A method for temperature and pressure composite calibration of an optical fiber high-temperature pressure sensor, characterized in that, include: S1, open the cavity cover (8), place the high temperature probe of the fiber optic high temperature pressure sensor to be tested in the through hole B (52) of the insulation layer (4), and ensure that the high temperature probe and the thermocouple (6) are in the same plane position. S2, the pigtail of the fiber optic high-temperature pressure sensor under test is led out from the cabin part (9), and the cavity cover (8) is sealed to the outer cavity (1) by screws and polytetrafluoroethylene gaskets; S3, turn on the vacuum system (14) to evacuate the inside of the pressure chamber to a vacuum; S4, connect the water cooling pipe (7) to the water chiller, turn on the water chiller, and cool the outer cavity (1) through the water cooling pipe (7) to form a temperature gradient range; S5, based on the current calibration temperature point, control the heating module (3) to work through the temperature controller (17) and adjust the temperature of the insulation zone to the current calibration temperature point; after the temperature of the insulation zone reaches the current calibration temperature point, keep it warm for a period of time; S6, open the high-purity argon cylinder (15), observe the pressure reading of the standard pressure sensor (13), and perform pressure calibration at the current calibration temperature point according to the calibration pressure point; S7. After the pressure stroke test at the current calibration temperature point is completed, repeat the above steps S3~S6 to perform pressure calibration at the next calibration temperature point. S8. Based on the readings of the thermocouple (6) and the standard pressure sensor (13), the temperature and pressure composite calibration test of the fiber optic high-temperature pressure sensor under test is completed by using a comparative calibration method.

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