Ultralow temperature test system and test method for pressure sensor

Abstract

The invention provides a pressure sensor ultralow temperature test system and test method. The pressure sensor ultralow temperature test system comprises an operation cabinet; the test box is arranged at the top of the operation cabinet; the bearing support is arranged in the test box and used for bearing the temperature sensor and at least one pressure sensor to be tested at the same time; the gas supply unit is connected with the test box and used for supplying gas to the temperature sensor and the pressure sensor at the same time; the ultralow-temperature supply unit is connected with the test box and used for providing an ultralow-temperature environment for the temperature sensor and the pressure sensor; and the acquisition control unit is arranged on the operation cabinet, is electrically connected with the gas supply unit, the ultralow temperature supply unit and the temperature sensor respectively, and is used for controlling the gas supply unit and the ultralow temperature supply unit and acquiring the actual pressure and the actual temperature of the pressure sensor. The pressure sensor ultralow temperature test system and test method provided by the invention are simple and convenient, high in detection efficiency, and convenient for subsequent calibration work.

Description

Technical Field

[0001] The present application relates to the technical field of pressure sensor testing, and in particular to an ultra-low temperature testing system and testing method for a pressure sensor. Background Art

[0002] In recent years, based on the needs of ground testing of aerospace engines, it is necessary to build an ultra-low temperature environment to calibrate and test special pressure sensors to ensure that the special pressure sensors can work accurately and reliably.

[0003] In the prior art, Hu Rui et al. developed a cryogenic pressure sensor calibration system that is continuously adjustable in the temperature range of (79-150)K. The system uses liquid nitrogen as the cooling source, and its temperature control accuracy is no more than ±2K. Li Zhengbing et al. developed a cryogenic pressure sensor calibration system that is continuously adjustable in the temperature range of (80-300)K. The expanded uncertainty of the calibration device is 0.3% (k=2). Li Zhi et al. developed a cryogenic pressure sensor calibration system that is continuously adjustable in the temperature range of (77-293)K. The uncertainty of the system is better than 1% (k=2). Li Xing et al. developed a cryogenic pressure sensor calibration system that is continuously adjustable in the temperature range of (20-80)K. The temperature control accuracy of the system is no more than ±0.2K. This is also the first time that my country has realized continuous variable temperature calibration of cryogenic pressure sensors in the liquid hydrogen temperature range. Zhang Jian et al. also designed and studied the cryogenic pressure sensor calibration device, and successfully realized the calibration of the self-developed ultra-low temperature pressure sensor in the pressure range of -253℃~-163℃ and 0MPa~2MPa.

[0004] Although the development of the above ultra-low temperature environment pressure sensor calibration system has achieved temperature adjustment, the temperature measured by the system is different from the actual temperature of the pressure sensor, resulting in poor calibration effect of the pressure sensor. In addition, there are also problems such as complex system structure, cumbersome operation, and low calibration efficiency. Therefore, a simple and accurate pressure sensor ultra-low temperature test system is urgently needed. Summary of the invention

[0005] In view of this, the purpose of the present application is to propose a pressure sensor ultra-low temperature testing system and testing method to solve the related problems mentioned in the background technology.

[0006] In a first aspect of the present application, a pressure sensor ultra-low temperature testing system is provided, comprising: an operating cabinet; a test box, arranged on the top of the operating cabinet; a supporting bracket, arranged in the test box, and used to simultaneously support a temperature sensor and at least one pressure sensor to be tested; an air supply unit, connected to the test box, and used to simultaneously supply air to the temperature sensor and the pressure sensor; an ultra-low temperature supply unit, connected to the test box, and used to provide an ultra-low temperature environment for the temperature sensor and the pressure sensor; a collection control unit, arranged on the operating cabinet, and electrically connected to the air supply unit, the ultra-low temperature supply unit, and the temperature sensor, respectively, for controlling the air supply unit and the ultra-low temperature supply unit, and collecting the actual pressure and actual temperature of the pressure sensor.

[0007] Furthermore, the test box includes a box body and a box cover, the box body includes a sleeved outer shell and an inner liner, an insulating layer is provided between the outer shell and the inner liner, a sealing strip is provided on the box cover, and a heating belt is provided on the mating surfaces of the box body and the box cover.

[0008] Furthermore, the supporting bracket includes a porous plate, on which a plurality of mounting seats are detachably mounted, the mounting seats are arranged to pass through the porous plate, one end of the mounting seat is connected to an adapter, and the adapter is used to connect the temperature sensor, the pressure sensor or the blind plate; among the plurality of mounting seats, one mounting seat is connected to the temperature sensor, and the remaining mounting seats are connected to the pressure sensor or the blind plate.

[0009] Furthermore, a cooling cover is provided in the test box, and the cooling cover is mounted on the temperature sensor and the pressure sensor for balancing the temperature; a lead-in port is provided on the box body, and the lead-in port is used for electrically connecting the pressure sensor to the outside of the test box.

[0010] Furthermore, the gas supply unit includes a gas cylinder, a pressure reducing valve, an air release valve and a pressure regulator, the gas cylinder is used to store test gas; the pressure reducing valve is connected to the gas cylinder, and is used to reduce the pressure of the test gas; the pressure regulator is arranged in the operating cabinet, one end is connected to the pressure reducing valve, and the other end is connected to the test box, and is used to supply gas to the test box. The gas supply accuracy of the pressure regulator is 5‰, and it is electrically connected to the acquisition control unit; the air release valve is connected between the pressure reducing valve and the pressure regulator, and is used to discharge the test gas.

[0011] Furthermore, the air supply unit further comprises a plurality of four-way connectors connected in series, and each of the four-way connectors is respectively connected to two of the mounting seats.

[0012] Furthermore, the ultra-low temperature supply unit includes a liquid storage tank, a liquid inlet valve, a liquid outlet valve and a liquid level sensor, the liquid storage tank is used to store ultra-low temperature liquid, the liquid inlet valve, the liquid outlet valve and the liquid level sensor are arranged in the operating cabinet and are electrically connected to the acquisition control unit; one end of the liquid inlet valve is connected to the liquid storage tank, and the other end is connected to the test box, for injecting the ultra-low temperature liquid into the test box; one end of the liquid outlet valve is connected to the bottom of the test box, and the other end is connected to the outside of the operating cabinet, for discharging the ultra-low temperature liquid; the liquid level sensor is connected to the test box, and is used to measure the liquid level of the ultra-low temperature liquid in the test box.

[0013] Furthermore, an exhaust pipe is provided in the test box, one end of which is located at the opening of the box body, and the other end passes through the operating cabinet to communicate with the outside world, so as to discharge the gas vaporized from the ultra-low temperature liquid; a lead tube is provided at the bottom of the test box, and the temperature sensor is electrically connected to the acquisition control unit through the lead tube.

[0014] Furthermore, the ultra-low temperature supply unit also includes a plurality of interconnected liquid inlet pipes, each of which is provided with a plurality of liquid inlets. Each layer of the liquid inlet pipes is located in the test box and is arranged around the supporting bracket, and the liquid inlet pipes on the bottom layer are connected to the liquid inlet valve.

[0015] A second aspect of the present application provides a method for ultra-low temperature testing of a pressure sensor, using the ultra-low temperature testing system for the pressure sensor as described in the first aspect above, the method comprising: opening the test box, installing a temperature sensor and a pressure sensor to be tested on the supporting bracket, and then closing the test box; opening the ultra-low temperature supply unit through the acquisition control unit to provide ultra-low temperature liquid into the test box so that the liquid level of the ultra-low temperature liquid in the test box is higher than the height of the temperature sensor or the pressure sensor; opening the air supply unit through the acquisition control unit to supply air to the temperature sensor and the pressure sensor at the same time; and acquiring the actual pressure and actual temperature of the pressure sensor through the acquisition control unit.

[0016] As can be seen from the above, the ultra-low temperature test system and test method of the pressure sensor provided by the present application, the ultra-low temperature test system of the pressure sensor includes: an operating cabinet; a test box, arranged on the top of the operating cabinet; a bearing bracket, arranged in the test box, for simultaneously carrying a temperature sensor and at least one pressure sensor to be tested; a gas supply unit, connected to the test box, for simultaneously supplying gas to the temperature sensor and the pressure sensor; an ultra-low temperature supply unit, connected to the test box, for providing an ultra-low temperature environment to the temperature sensor and the pressure sensor; an acquisition control unit, arranged on the operating cabinet, electrically connected to the gas supply unit, the ultra-low temperature supply unit and the temperature sensor, respectively, for controlling the gas supply unit and the ultra-low temperature supply unit, and collecting the actual pressure and actual temperature of the pressure sensor. By simultaneously supplying gas to the pressure sensor and the temperature sensor and providing an ultra-low temperature environment, the environment in which the temperature sensor is located can be made almost consistent with the environment in which the pressure sensor is located, so that the temperature measured by the temperature sensor can represent the actual temperature of the pressure sensor, cooperate with the gas supply unit to obtain the actual pressure, and facilitate the subsequent pressure calibration of the pressure sensor according to the actual pressure and the actual temperature, and the calibration effect is good; the bearing bracket can be set to test multiple pressure sensors at the same time, thereby improving the detection efficiency. The pressure sensor ultra-low temperature testing system and testing method have simple structure, convenient operation, high detection efficiency, can accurately measure the actual temperature of the pressure sensor during testing, and are convenient for subsequent calibration work. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of the three-dimensional structure of an ultra-low temperature testing system for a pressure sensor in an embodiment of the present application;

[0019] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the ultra-low temperature test system for medium pressure sensors;

[0020] Figure 3 This is a schematic diagram of the internal structure of the operating cabinet and the test box in the embodiment of the present application;

[0021] Figure 4 This is a schematic diagram of the three-dimensional structure of the load-bearing bracket in an embodiment of the present application;

[0022] Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure of the middle load-bearing bracket;

[0023] Figure 6 Schematic diagram of a process for ultra-low temperature testing of a pressure sensor in an embodiment of the present application.

[0024] Figure numerals: 1. operating cabinet; 2. test box; 2-1. box body; 2-2. box cover; 2-3. cooling cover plate; 2-4. lead-in port; 2-5. exhaust pipe; 2-6. lead-in pipe; 3. supporting bracket; 3-1. mounting seat; 3-2. adapter; 3-3. blind plate; 3-4. porous plate; 4. temperature sensor; 5. pressure sensor; 6. gas supply unit; 6-1. gas cylinder; 6-2. pressure reducing valve; 6-3. air relief valve; 6-4. pressure regulator; 6-5. four-way connector; 7. ultra-low temperature supply unit; 7-1. liquid storage tank; 7-2. liquid inlet valve; 7-3. liquid outlet valve; 7-4. liquid level sensor; 7-5. liquid inlet pipe; 8. acquisition control unit. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0026] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] In the process of implementing the present application, it was found that the prior art usually simply sets the temperature sensor in the test box, for example, on the side wall of the box, and uses the measured temperature to represent the actual temperature of the pressure sensor performing the pressure test in the test box. During the pressure test of the pressure sensor, the test gas may change the temperature of the environment around the pressure sensor, and the temperature sensor is not affected by the test gas. Therefore, the measured temperature cannot accurately represent the temperature of the pressure sensor during the pressure test, which leads to inaccurate calibration of the pressure sensor. It can be considered to correct this part of the influence.

[0028] Below, through specific embodiments and in combination with the attached Figures 1 to 6 To describe the technical solution of this application in detail.

[0029] Some embodiments of the present application provide a pressure sensor ultra-low temperature testing system, such as Figure 1 and Figure 2 As shown, it includes: an operating cabinet 1; a test box 2, which is arranged on the top of the operating cabinet 1; a supporting bracket 3, which is arranged in the test box 2 and is used to simultaneously carry a temperature sensor 4 and at least one pressure sensor 5 to be tested; an air supply unit 6, which is connected to the test box 2 and is used to simultaneously supply air to the temperature sensor 4 and the pressure sensor 5; an ultra-low temperature supply unit 7, which is connected to the test box 2 and is used to provide an ultra-low temperature environment for the temperature sensor 4 and the pressure sensor 5; a collection control unit 8, which is arranged on the operating cabinet 1 and is electrically connected to the air supply unit 6, the ultra-low temperature supply unit 7 and the temperature sensor 4, respectively, and is used to control the air supply unit 6 and the ultra-low temperature supply unit 7, and collect the actual pressure and actual temperature of the pressure sensor 5.

[0030] like Figure 1 As shown, the pressure sensor ultra-low temperature test system includes a stacked operating cabinet 1 and a test box 2. The operating cabinet 1 is used to arrange some pipelines and lines, and universal wheels can be set at the bottom for easy movement; the test box 2 is used to perform pressure testing on the pressure sensor 5.

[0031] like Figure 2 As shown, a bearing bracket 3 is provided in the test box 2, which can simultaneously bear at least one temperature sensor 4 and multiple pressure sensors 5, so as to facilitate simultaneous pressure testing of multiple pressure sensors 5, and the temperature sensor 4 is used to measure the temperature during the pressure test.

[0032] like Figure 2 As shown, the air supply unit 6 is connected to the test box 2 through the operating cabinet 1, and is used to supply air to the temperature sensor 4 and the pressure sensor 5 at the same time; the ultra-low temperature supply unit 7 is connected to the test box 2 through the operating cabinet 1, and is used to provide an ultra-low temperature environment to the temperature sensor 4 and the pressure sensor 5 at the same time. The temperature of the ultra-low temperature environment is, for example, -196°C or below, and there is no specific limitation.

[0033] like Figure 2 As shown, the acquisition control unit 8 is arranged on the operating cabinet 1, and realizes the communication data transmission of analog signals and the communication of digital signals through the PLC programmable logic controller. It is electrically connected to the gas supply unit 6, the ultra-low temperature supply unit 7 and the temperature sensor 4 respectively, and is used to control the gas supply unit 6 to supply gas, control the ultra-low temperature supply unit 7 to provide an ultra-low temperature environment, and collect the actual pressure and actual temperature of the pressure sensor 5, where the actual pressure is the gas supply pressure measured by the gas supply unit 6, and the actual temperature is the temperature measured by the temperature sensor 4.

[0034] By supplying air to the pressure sensor 5 and the temperature sensor 4 at the same time and providing an ultra-low temperature environment, the environment in which the temperature sensor 4 is located can be made almost consistent with the environment in which the pressure sensor 5 is located. In this way, the temperature measured by the temperature sensor 4 can represent the actual temperature of the pressure sensor 5, and cooperate with the air supply unit 6 to obtain the actual pressure. The subsequent pressure calibration of the pressure sensor 5 is convenient according to the actual pressure and the actual temperature, and the calibration effect is good. The supporting bracket 3 is set to test multiple pressure sensors 5 at the same time, thereby improving the detection efficiency.

[0035] The pressure sensor ultra-low temperature test system has a simple structure, is easy to operate, and has high detection efficiency. It can accurately measure the actual temperature of the pressure sensor 5 during the test, and is convenient for subsequent calibration work.

[0036] In some embodiments, Figure 2 As shown, the test box 2 includes a box body 2-1 and a box cover 2-2, the box body 2-1 includes a sleeved outer shell and an inner liner, an insulating layer is provided between the outer shell and the inner liner, a sealing strip is provided on the box cover 2-2, and a heating belt is provided on the mating surfaces of the box body 2-1 and the box cover 2-2.

[0037] like Figure 2 As shown, the test box 2 includes a box body 2-1 and a box cover 2-2 which are rotatably connected. The box cover 2-2 can open and close the box body 2-1, and a lock can be set on the side wall to ensure that the test environment is closed; the box body 2-1 includes a sleeved outer shell and an inner liner, and an aerogel insulation blanket can be used as an inner lining to ensure the thermal insulation effect. An insulation layer is provided between the outer shell and the inner liner. The insulation layer is, for example, foamed polyurethane, which can fill the interlayer and insulate to ensure the stability of the ultra-low temperature environment; a sealing strip, such as an E-type silicone strip, is provided on the box cover 2-2 to further ensure the sealing effect; a heating belt is provided on the mating surface of the box body 2-1 and the box cover 2-2, and the heating belt can be heated when the temperature is lower than 5°C to avoid frost on the mating surface and the inability to open the box body 2-1.

[0038] In some embodiments, Figure 4 and Figure 5 As shown, the supporting bracket 3 includes a porous plate 3-4, and a plurality of mounting seats 3-1 are detachably mounted on the porous plate 3-4, and the mounting seats 3-1 are arranged through the porous plate 3-4, and one end of the mounting seat 3-1 is connected to an adapter 3-2, and the adapter 3-2 is used to connect the temperature sensor 4, the pressure sensor 5 or the blind plate 3-3; among the plurality of mounting seats 3-1, one mounting seat 3-1 is connected to the temperature sensor 4, and the remaining mounting seats 3-1 are connected to the pressure sensor 5 or the blind plate 3-3.

[0039] like Figure 4As shown, the supporting bracket 3 includes a porous plate 3-4, which can facilitate the upper and lower circulation of ultra-low temperature liquid to quickly form an ultra-low temperature environment. The porous plate 3-4 can be set on the angle bracket in the box body 2-1, and the specific details are not limited; a plurality of mounting seats 3-1 can be detachably mounted on the porous plate 3-4, for example, 12 mounting seats 3-1 are connected by bolts, and the mounting seat 3-1 is, for example, a step structure, and a part of the area can pass through the through hole of the porous plate 3-4, such as Figure 5 As shown, a through hole is provided in the middle of the mounting base 3-1 for the test gas to pass through; an adapter 3-2 is connected to the end of the mounting base 3-1 away from the bottom of the box body 2-1, such as a threaded connection, and the adapter 3-2 is used for detachably connecting the temperature sensor 4, the pressure sensor 5 or the blind plate 3-3, such as a threaded connection. The adapter 3-2 is a hollow structure and is used to provide test gas to the temperature sensor 4 and the pressure sensor 5. When the adapter 3-2 is connected to the blind plate 3-3, the test gas pipeline can be closed to avoid affecting the measurement of other temperature sensors 4 or pressure sensors 5; the models of multiple adapters 3-2 can be different, so as to connect different pressure sensors 5 or temperature sensors 4 and realize multi-model measurement.

[0040] like Figure 5 As shown, a mounting seat 3-1 at the corner is connected to the temperature sensor 4, and among the remaining 11 mounting seats 3-1, 2 are connected to the blind plate 3-3, and 9 are connected to the pressure sensor 5, which can meet the pressure test of the 9 pressure sensors 5 at the same time; the blind plate 3-3 can be against the bottom of the cooling cover plate 2-3 to play a supporting role.

[0041] In some embodiments, Figure 2 and Figure 3 As shown, a cooling cover plate 2-3 is provided in the test box 2, and the cooling cover plate 2-3 is mounted on the temperature sensor 4 and the pressure sensor 5 for balancing the temperature; a lead-in port 2-4 is provided on the box body 2-1, and the lead-in port 2-4 is used for electrical connection between the pressure sensor 5 and the outside of the test box 2.

[0042] like Figure 3 As shown, the cold-conducting cover plate 2-3 is, for example, an aluminum plate, which can transfer heat. When the ultra-low temperature liquid is just injected into the box body 2-1, the temperature of the sensors at different positions is not the same. By setting the cold-conducting cover plate 2-3 on each sensor, the temperature can be quickly equalized and the detection efficiency can be improved. In addition, the cold-conducting cover plate 2-3 is located above the porous plate 3-4, which can also block debris and protect the sensor.

[0043] like Figure 3As shown, a lead port 2-4 is provided at the opening of the box body 2-1, and the pressure sensor 5 in the box body 2-1 can be connected to the outside through the lead port 2-4, for example, connected to an external computer, to obtain the test pressure of the pressure sensor 5, and then calibrate the pressure sensor 5 according to the actual pressure and actual temperature collected by the acquisition control unit 8. The calibration method can adopt the pressure sensor calibration method in the relevant technology, which will not be repeated here.

[0044] In some embodiments, Figure 2 As shown, the gas supply unit 6 includes a gas cylinder 6-1, a pressure reducing valve 6-2, a bleed valve 6-3 and a pressure regulator 6-4, wherein the gas cylinder 6-1 is used to store the test gas; the pressure reducing valve 6-2 is connected to the gas cylinder 6-1, and is used to reduce the pressure of the test gas; the pressure regulator 6-4 is arranged in the operating cabinet 1, one end of which is connected to the pressure reducing valve 6-2, and the other end of which is connected to the test box 2, and is used to supply gas to the test box 2. The gas supply accuracy of the pressure regulator 6-4 is 5‰, and it is electrically connected to the acquisition control unit 8; the bleed valve 6-3 is connected between the pressure reducing valve 6-2 and the pressure regulator 6-4, and is used to discharge the test gas.

[0045] like Figure 2 As shown, the gas cylinder 6-1 is used to store the test gas, and the gas cylinder 6-1 is, for example, a high-pressure helium cylinder; the pressure reducing valve 6-2 is arranged near the gas cylinder 6-1 and outside the operating cabinet 1, and can reduce the pressure of the test gas to a pressure slightly higher than the pressure required for the test, and adjust it according to the test requirements; the pressure regulator 6-4 is arranged in the operating cabinet 1, and is used to accurately control the pressure of the test gas, and is connected to the mounting seat 3-1 through a pipeline to deliver it to the pressure sensor 5 and the temperature sensor 4. The pressure regulator 6-4 is, for example, a WIKA CPC400 pressure regulator, a WIKA cpc6000 pressure regulator or a Drucker pressure regulator, etc., without specific limitation, which can make the gas supply accuracy reach 5‰, ensuring accurate acquisition of the actual pressure; the air relief valve 6-3 is arranged outside the operating cabinet 1. After the test is completed, opening the air relief valve 6-3 can quickly release the pressure to ensure safety.

[0046] like Figure 2 As shown, a partition is provided in the operating cabinet 1, and the partition is located above the pressure regulator 6-4 to play a protective role and ensure high-precision gas supply.

[0047] In some embodiments, Figure 4 As shown, the air supply unit 6 further includes a plurality of four-way connectors 6 - 5 connected in series, and each of the four-way connectors 6 - 5 is respectively connected to two of the mounting seats 3 - 1 .

[0048] like Figure 3As shown, the pressure regulator 6-4 is connected to the test box 2 through a pipeline, and then connected to multiple four-way connectors 6-5 in series, such as Figure 4 As shown, the four-way connector 6-5 is used to divert the test gas and then transmit it to the mounting seat 3-1, so that multiple sensors can be tested at the same time with the same gas environment; one port of the four-way connector 6-5 at the end is closed.

[0049] In some embodiments, Figure 2 and Figure 3 As shown, the ultra-low temperature supply unit 7 includes a liquid storage tank 7-1, a liquid inlet valve 7-2, a liquid outlet valve 7-3 and a liquid level sensor 7-4. The liquid storage tank 7-1 is used to store ultra-low temperature liquid. The liquid inlet valve 7-2, the liquid outlet valve 7-3 and the liquid level sensor 7-4 are arranged in the operating cabinet 1 and are electrically connected to the acquisition control unit 8; one end of the liquid inlet valve 7-2 is connected to the liquid storage tank 7-1, and the other end is connected to the test box 2, for injecting the ultra-low temperature liquid into the test box 2; one end of the liquid outlet valve 7-3 is connected to the bottom of the test box 2, and the other end is connected to the outside of the operating cabinet 1, for discharging the ultra-low temperature liquid; the liquid level sensor 7-4 is connected to the test box 2, for measuring the liquid level height of the ultra-low temperature liquid in the test box 2.

[0050] like Figure 2 As shown, the liquid storage tank 7-1 is used to store ultra-low temperature liquid, and the liquid storage tank 7-1 is, for example, a self-pressurized liquid nitrogen tank; a liquid inlet valve 7-2 is provided in the operating cabinet 1, which is used to control the ultra-low temperature liquid to enter the box body 2-1 to provide an ultra-low temperature environment; a liquid outlet valve 7-3 is also provided in the operating cabinet 1. After the test is completed, or when there is too much ultra-low temperature liquid in the box body 2-1, the ultra-low temperature liquid can be discharged, for example, connected to an external recovery tank for recovery, etc.; a liquid level sensor 7-4 is also provided in the operating cabinet 1, which is used to measure the liquid level of the ultra-low temperature liquid in the test box 2 to ensure the test effect. During the test, the liquid level should be higher than the mating surface height of the sensor and the adapter 3-2, for example, higher than the height of the cooling cover 2-3, to ensure the stability of the ultra-low temperature environment.

[0051] In some embodiments, Figure 2 and Figure 3 As shown, the test box 2 is provided with an exhaust pipe 2-5, one end of which is located at the opening of the box body 2-1, and the other end passes through the operating cabinet 1 to communicate with the outside world, so as to discharge the gas vaporized from the ultra-low temperature liquid; a lead tube 2-6 is provided at the bottom of the test box 2, and the temperature sensor 4 is electrically connected to the acquisition control unit 8 through the lead tube 2-6.

[0052] like Figure 3As shown, the test box 2 is provided with an exhaust pipe 2-5, one end of which is located at the opening of the box body 2-1 and is higher than the liquid level, and the other end passes through the operating cabinet 1 to communicate with the outside world, and is used to discharge the gas after the ultra-low temperature liquid is vaporized to ensure safety; the test box 2 is also provided with a lead tube 2-6, which is higher than the liquid level. The lead tube 2-6 runs through the bottom of the box body 2-1, so that the temperature sensor 4 can be electrically connected to the collection control unit 8 through the lead tube 2-6, which is convenient for collecting the actual temperature.

[0053] In some embodiments, Figure 3 and Figure 4 As shown, the ultra-low temperature supply unit 7 also includes a plurality of interconnected liquid inlet pipes 7-5, and a plurality of liquid inlet ports are provided on the liquid inlet pipes 7-5. Each layer of the liquid inlet pipes 7-5 is located in the test box 2 and is arranged around the supporting bracket 3. The liquid inlet pipe 7-5 on the bottom layer is connected to the liquid inlet valve 7-2.

[0054] like Figure 3 As shown, the ultra-low temperature supply unit 7 includes two layers of spaced and connected liquid inlet pipes 7-5, and the liquid inlet pipe 7-5 at the bottom layer is connected to the liquid inlet valve 7-2. Figure 4 As shown, each layer of the liquid inlet pipe 7-5 is provided with multiple liquid inlets, and the liquid inlet pipe 7-5 is arranged around the supporting bracket 3, so that ultra-low temperature liquid can be quickly provided to each position of the supporting bracket 3, the temperature can be quickly balanced, and the detection efficiency can be improved.

[0055] In some embodiments, the gas supply unit 6 of the pressure sensor ultra-low temperature testing system is used to supply the pressure sensor 5 with a test gas with an accuracy of 5‰; the ultra-low temperature supply unit 7 is used to maintain the pressure sensor 5 in an ultra-low temperature environment of -196°C during testing; the acquisition control unit 8 is used to collect the actual temperature, actual pressure, and liquid level of the ultra-low temperature liquid of the pressure sensor 5 during testing in real time, and control the liquid inlet and outlet of the ultra-low temperature supply unit 7.

[0056] The leads of each solenoid valve, liquid level sensor 7-4, and temperature sensor 4 in the ultra-low temperature test system of the pressure sensor are connected to the PLC industrial computer of the acquisition control unit 8, which controls the closing or opening of each solenoid valve, as well as the numerical display of the liquid level sensor 7-4 and the temperature sensor 4; the acquisition control unit 8 displays the initial screen, monitoring screen, system parameters, liquid level curve, temperature curve, and data export through software programming, and can store and export the state parameters of each test. The liquid level sensor 7-4 can be programmed to set the rated value. When the actual value is lower than the rated value, the acquisition control unit 8 controls the liquid inlet valve 7-2 to replenish the liquid.

[0057] The air outlet pipeline of the pressure regulator 6-4 is connected to six high-pressure four-way connectors 6-5, and the six four-way connectors 6-5 have a total of 12 ports, one of which is connected to the temperature sensor 4, and the remaining 11 ports are connected to the pressure sensor 5 through the adapter 3-2.

[0058] The pressure sensor ultra-low temperature test system integrates a bearing bracket 3, a temperature sensor 4, and a liquid level sensor 7-4 in a test box 2. Eleven pressure sensors 5 to be tested can be quickly and easily installed on the bearing bracket 3, and the test of the 11 pressure sensors 5 can be completed at one time, which simplifies the installation process and improves the detection efficiency. A detachable adapter 3-2 is designed between the bearing bracket 3 and the pressure sensor 5. When the specification and model of the pressure sensor 5 to be tested changes, a new adapter 3-2 can be designed to match the new specification of the pressure sensor 5 to meet the test of the new specification and model of the pressure sensor 5, thereby realizing one machine with multiple uses. By connecting the lead of the temperature sensor 4, the lead of the liquid level sensor 7-4, the control line of the liquid inlet valve 7-2 and the liquid outlet valve 7-3, and the data line of the pressure regulator 6-4 through the acquisition control unit 8, data acquisition and liquid inlet / discharge control can be conveniently realized, thereby improving the human-computer interactivity of the test system.

[0059] The description of the present application is given for the purpose of illustration and description, and is not intended to be exhaustive or to limit the present application to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present application, and to enable those of ordinary skill in the art to understand the present application and thus design various embodiments with various modifications suitable for specific purposes.

[0060] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may also be combined, and there are many other variations of different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0061] Based on the same inventive concept, the present application also provides a pressure sensor ultra-low temperature testing method, using the pressure sensor ultra-low temperature testing system as described in any of the above embodiments, such as Figure 6 As shown, the ultra-low temperature testing method of the pressure sensor includes:

[0062] S1 . Open the test box 2 , install the temperature sensor 4 and the pressure sensor 5 to be tested on the support bracket 3 , and then close the test box 2 .

[0063] S2. Turn on the ultra-low temperature supply unit 7 through the acquisition control unit 8 to provide ultra-low temperature liquid into the test box 2, so that the liquid level of the ultra-low temperature liquid in the test box 2 is higher than the height of the temperature sensor 4 or the pressure sensor 5.

[0064] Ensure that the temperature sensor 4 and the pressure sensor 5 have the same ultra-low temperature environment.

[0065] S3. Turn on the air supply unit 6 through the acquisition control unit 8 to supply air to the temperature sensor 4 and the pressure sensor 5 at the same time.

[0066] Make sure that the temperature sensor 4 and the pressure sensor 5 have the same gas environment.

[0067] S4. The actual pressure and actual temperature of the pressure sensor 5 are collected by the collection control unit 8 .

[0068] The acquisition control unit 8 acquires the adjustment pressure of the pressure regulator 6-4, that is, the actual pressure of the pressure sensor 5; the acquisition control unit 8 acquires the temperature of the temperature sensor 4, that is, the actual temperature of the pressure sensor 5; the pressure sensor 5 can output the test pressure to the outside through the lead port 2-4, and the test accuracy of the pressure sensor 5 can be determined by comparing the test pressure and the actual pressure; at the same actual temperature, the test pressure can be calibrated according to the corresponding actual pressure to complete the calibration of the pressure sensor 5.

[0069] The ultra-low temperature testing method for the pressure sensor is easy to operate and has high detection efficiency. It focuses on the convenient and efficient testing and calibration of the pressure sensor 5 in a fixed-point ultra-low temperature environment. By maintaining the ultra-low temperature environment and supplying high-precision pressure, high-precision testing and calibration of multiple pressure sensors 5 can be achieved simultaneously, providing technical support for promoting ground testing of aerospace vehicle engines.

[0070] Specifically, the ultra-low temperature test method of the pressure sensor may include: opening the box cover 2-2, installing the pressure sensor 5 on the bearing bracket 3, and closing the box cover 2-2; starting the liquid inlet valve 7-2 to add ultra-low temperature liquid to the box body 2-1 until the rated liquid level is reached and stopped. When the liquid level is lowered due to the gasification of the ultra-low temperature liquid during the test, the acquisition control unit 8 can automatically open the liquid inlet valve 7-2 for liquid replenishment according to the set parameters; starting the gas storage bottle 6-1 to supply gas to the test box 2, adjusting the gas supply pressure through the pressure regulator 6-4, and recording after the pressure value is stable; the acquisition control unit 8 timely collects data from the temperature sensor 4, the liquid level sensor 7-4, and the pressure regulator 6-4 through the lead; after the test is completed, the liquid inlet valve 7-2 is closed by the acquisition control unit 8, and the liquid outlet valve 7-3 is started until the ultra-low temperature liquid is completely discharged from the box body 2-1; the gas storage bottle 6-1 is closed, and the air release valve 6-3 is started to release the air pressure in the box body 2-1 to 0MPa; the acquisition control unit 8 generates a test data packet based on the measurement results, and the data can be exported and processed using a mobile storage medium.

[0071] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0072] In addition, when details are set forth to describe exemplary embodiments of the present application, it is obvious to those skilled in the art that the present application embodiments can be implemented without these details or with changes in these details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0073] While the present application has been described in conjunction with embodiments thereof, many alternatives, modifications and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description.

[0074] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A pressure sensor ultra-low temperature test system, characterized in that: include: Operation cabinet; A test box, arranged on the top of the operating cabinet; A bearing bracket, arranged in the test box, for simultaneously bearing a temperature sensor and at least one pressure sensor to be tested; An air supply unit, connected to the test box, and used to supply air to the temperature sensor and the pressure sensor at the same time; An ultra-low temperature supply unit, connected to the test box, for providing an ultra-low temperature environment for the temperature sensor and the pressure sensor; The acquisition control unit is arranged on the operating cabinet and is electrically connected to the gas supply unit, the ultra-low temperature supply unit and the temperature sensor respectively, and is used to control the gas supply unit and the ultra-low temperature supply unit, and to acquire the actual pressure and actual temperature of the pressure sensor.

2. The pressure sensor ultra-low temperature testing system according to claim 1, characterized in that: The test box comprises a box body and a box cover, wherein the box body comprises a sleeved outer shell and an inner liner, an insulating layer is arranged between the outer shell and the inner liner, a sealing strip is arranged on the box cover, and a heating belt is arranged on the mating surfaces of the box body and the box cover.

3. The pressure sensor ultra-low temperature testing system according to claim 2, characterized in that: The supporting bracket comprises a porous plate, on which a plurality of mounting seats are detachably mounted, the mounting seats are arranged through the porous plate, one end of the mounting seats is connected to an adapter, and the adapter is used to connect the temperature sensor, the pressure sensor or the blind plate; Among the multiple mounting seats, one mounting seat is connected to the temperature sensor, and the remaining mounting seats are connected to the pressure sensor or the blind plate.

4. The pressure sensor ultra-low temperature testing system according to claim 3, characterized in that: A cooling cover plate is provided in the test box, and the cooling cover plate is sleeved on the temperature sensor and the pressure sensor for balancing the temperature; The box body is provided with a lead-in port, and the lead-in port is used for electrically connecting the pressure sensor with the outside of the test box.

5. The pressure sensor ultra-low temperature testing system according to claim 4, characterized in that: The gas supply unit comprises a gas storage bottle, a pressure reducing valve, a gas relief valve and a pressure regulator, wherein the gas storage bottle is used to store the test gas; The pressure reducing valve is connected to the gas storage bottle and is used to reduce the pressure of the test gas; The pressure regulator is arranged in the operating cabinet, one end of which is connected to the pressure reducing valve, and the other end of which is connected to the test box, and is used to supply gas to the test box. The gas supply accuracy of the pressure regulator is 5‰, and the pressure regulator is electrically connected to the acquisition control unit; The air release valve is connected between the pressure reducing valve and the pressure regulator, and is used for discharging the test gas.

6. The pressure sensor ultra-low temperature testing system according to claim 5, characterized in that: The air supply unit further comprises a plurality of four-way connectors connected in series, each of the four-way connectors being respectively connected to two of the mounting seats.

7. The pressure sensor ultra-low temperature testing system according to claim 6, characterized in that: The ultra-low temperature supply unit comprises a liquid storage tank, a liquid inlet valve, a liquid outlet valve and a liquid level sensor, wherein the liquid storage tank is used to store ultra-low temperature liquid, and the liquid inlet valve, the liquid outlet valve and the liquid level sensor are arranged in the operating cabinet and are electrically connected to the acquisition control unit; One end of the liquid inlet valve is connected to the liquid storage tank, and the other end is connected to the test box, so as to inject the ultra-low temperature liquid into the test box; One end of the liquid outlet valve is connected to the bottom of the test box, and the other end is connected to the outside of the operating cabinet for discharging the ultra-low temperature liquid; The liquid level sensor is in communication with the test box and is used to measure the liquid level of the ultra-low temperature liquid in the test box.

8. The pressure sensor ultra-low temperature testing system according to claim 7, characterized in that: The test box is provided with an exhaust pipe, one end of which is located at the opening of the box body, and the other end of which passes through the operating cabinet and is connected to the outside world, so as to exhaust the gas vaporized from the ultra-low temperature liquid; A lead tube is provided at the bottom of the test box, and the temperature sensor is electrically connected to the acquisition control unit through the lead tube.

9. The pressure sensor ultra-low temperature testing system according to claim 8, characterized in that: The ultra-low temperature supply unit also includes a plurality of interconnected liquid inlet pipes, each of which is provided with a plurality of liquid inlets. Each layer of the liquid inlet pipes is located in the test box and is arranged around the supporting bracket. The liquid inlet pipe at the bottom layer is connected to the liquid inlet valve.

10. A method for ultra-low temperature testing of a pressure sensor, characterized in that: Using the pressure sensor ultra-low temperature testing system as described in any one of claims 1 to 9, the pressure sensor ultra-low temperature testing method comprises: Open the test box, install the temperature sensor and the pressure sensor to be tested on the support bracket, and then close the test box; The ultra-low temperature supply unit is turned on by the acquisition control unit to provide ultra-low temperature liquid into the test box, so that the liquid level of the ultra-low temperature liquid in the test box is higher than the height of the temperature sensor or the pressure sensor; Turning on the air supply unit through the acquisition control unit to supply air to the temperature sensor and the pressure sensor at the same time; The actual pressure and actual temperature of the pressure sensor are collected by the collection control unit.

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