A gas testing device and method for simulating cryogenic vacuum environment

Abstract

This invention proposes a gas testing device and method simulating a low-temperature vacuum environment. The device includes a vacuum pump unit, a cold trap test chamber unit, an inlet unit, a testing unit, and a monitoring unit. The vacuum pump unit first evacuates and maintains a low vacuum to remove water vapor from the cold trap test chamber unit. Then, the cold trap is activated to cool the interior of the cold trap test chamber unit. This process ensures good heat transfer, maintaining a uniform temperature throughout the unit and preventing icing, thus improving testing accuracy. Once the internal temperature reaches a specific level (required for gas testing), the vacuum pump unit evacuates to a specific vacuum level (required for gas testing). Finally, the gas to be tested (such as H2S) is introduced, enabling precise measurement of the gas parameters under low-temperature vacuum conditions.

Description

Technical Field

[0001] This invention relates to the field of gas testing technology, and in particular to a gas testing device and method that simulates a low-temperature vacuum environment. Background Technology

[0002] Many gas tests are not conducted under natural conditions; they require testing gas parameters in extreme environments (such as low temperature and high vacuum). Therefore, testing devices capable of simulating low temperature and vacuum environments are needed for gas testing.

[0003] Current devices for simulating low-temperature vacuum environments generally use vacuum pumps for evacuation. For example, Chinese patent CN112937930A discloses a vacuum system for simulating a large dusty environment on the moon. The high-vacuum unit includes a cryogenic pump main evacuation system and a molecular pump auxiliary evacuation system. The cryogenic pump main evacuation system is used to establish and maintain the test pressure, while the molecular pump auxiliary evacuation system is used to assist the cryogenic pump in evacuating gas. The problem with this is that it causes the pressure inside the vacuum container to drop very low. Since there is no medium for heat transfer under high vacuum conditions, the temperature of the inner wall of the vacuum container will be inconsistent with the temperature of the center of the container, resulting in inaccurate test results. Therefore, it is not suitable for gas testing in simulating low-temperature vacuum environments. Summary of the Invention

[0004] In view of this, the present invention proposes a gas testing device and method for simulating a low-temperature vacuum environment, in order to solve the problem that when the pressure inside the vacuum container of the existing low-temperature vacuum environment simulating device is directly reduced to a very low level, the temperature of the inner wall of the vacuum container is inconsistent with the temperature of the center of the container, resulting in inaccurate gas testing results.

[0005] The technical solution of the present invention is implemented as follows: On one hand, the present invention provides a gas testing device for simulating a low-temperature vacuum environment, wherein the device includes:

[0006] Vacuum pump unit, cold trap test chamber unit, air intake unit, testing unit, and monitoring unit;

[0007] The vacuum pump unit is connected to the cold trap test chamber unit and is used to evacuate the cold trap test chamber unit and adjust the vacuum level of the cold trap test chamber unit.

[0008] The cold trap test cavity unit is used to cool the interior of the cold trap test cavity unit using a cold trap, thereby adjusting the internal temperature of the cold trap test cavity unit.

[0009] The air intake unit is connected to the cold trap test chamber unit and is used to transmit the gas to be tested to the cold trap test chamber unit.

[0010] The test unit is connected to the cold trap test chamber unit and is used to measure the parameters of the gas to be tested in the cold trap test chamber unit.

[0011] The monitoring unit is electrically connected to the vacuum pump unit and the cold trap test chamber unit, and is used to monitor the vacuum level of the vacuum pump unit and the vacuum level of the cold trap test chamber unit.

[0012] Based on the above technical solutions, preferably, the vacuum pump unit includes a mechanical pump and a molecular pump;

[0013] The mechanical pump is connected to the molecular pump via a bellows;

[0014] The molecular pump is connected to the cold trap test chamber unit via a suction baffle valve.

[0015] Based on the above technical solutions, preferably, the air intake unit includes a first adapter, a first shut-off valve, a second adapter, a gas buffer chamber, a third adapter, a second shut-off valve, a fourth adapter, and a rubber stopper seal.

[0016] One end of the first shut-off valve is connected to the cold trap test chamber unit via the first adapter, and the other end is connected to one end of the gas buffer chamber via the second adapter.

[0017] One end of the second shut-off valve is connected to the other end of the gas buffer chamber via the third adapter, and the other end is connected to one end of the rubber stopper seal via the fourth adapter.

[0018] Based on the above technical solutions, preferably, the testing unit includes a MEMS gas sensor and a resistance tester;

[0019] The MEMS gas sensor is connected to the cold trap test chamber unit;

[0020] The resistance tester is electrically connected to the MEMS gas sensor and is used to receive measurement data and output measurement results.

[0021] Based on the above technical solutions, preferably, the cold trap test chamber unit includes a cold trap chamber, a cold trap cover, a cold trap temperature controller, a temperature sensor, and a display;

[0022] The cold trap cavity is sealed to the cold trap cover;

[0023] The cold trap cover is connected to the vacuum pump unit, the air inlet unit, the testing unit, and the monitoring unit, respectively.

[0024] The cold trap temperature controller is located outside the cold trap cavity and is used to adjust the temperature of the inner wall of the cold trap cavity;

[0025] The temperature sensor is located around the test unit and is used to measure the temperature near the test unit;

[0026] The display is located outside the cold trap cavity and is used to display the temperature of the inner wall of the cold trap cavity and the temperature near the test unit.

[0027] Based on the above technical solutions, preferably, the monitoring unit includes a first resistance gauge, a second resistance gauge, a first ionization gauge, and a second ionization gauge;

[0028] The first resistance gauge is connected to the mechanical pump and is used to monitor the vacuum level of the mechanical pump;

[0029] The first ionization gauge is connected to the molecular pump and is used to monitor the vacuum level of the molecular pump;

[0030] The second resistance gauge is connected to the cold trap cover and is used to monitor the vacuum level of the cold trap cavity when the mechanical pump is working;

[0031] The second ionization gauge is connected to the cold trap cover and is used to monitor the vacuum level of the cold trap cavity when the molecular pump is working.

[0032] Based on the above technical solutions, preferably, the cold trap cover includes a first channel, a second channel, a third channel, a fourth channel, a fifth channel, and a sixth channel;

[0033] The first channel is used to connect to the intake unit;

[0034] The second channel is used to connect to the second resistor gauge;

[0035] The third channel is used as a backup channel;

[0036] The fourth channel is used to connect the molecular pump via the suction baffle valve;

[0037] The fifth channel is used to connect the test unit via an air plug;

[0038] The sixth channel is used to connect to the second ionization gauge;

[0039] The first, second, third, fourth, fifth, and sixth channels are staggered on the cold trap cover.

[0040] On the other hand, the present invention provides a gas testing method simulating a low-temperature vacuum environment, which employs the gas testing device for simulating a low-temperature vacuum environment as described above, and includes the following steps:

[0041] S1. Open the vacuum baffle valve, the first shut-off valve and the second shut-off valve, then turn on the mechanical pump to evacuate the cold trap test chamber unit, and start timing at the same time;

[0042] S2. After a certain vacuum level is reached in the first time T1, the mechanical pump and the first shut-off valve are turned off. Then, the syringe containing the gas to be tested is injected into the gas buffer chamber through the rubber stopper seal. After the injection is completed, the second shut-off valve is turned off.

[0043] S3. Turn on the cold trap to cool the inside of the cold trap test chamber unit. When the display shows that the temperature of the inner wall of the cold trap chamber and the temperature near the test unit have reached the required test temperature, maintain the temperature through the cold trap temperature controller, and at the same time turn on the molecular pump to evacuate the cold trap test chamber unit and restart the timing.

[0044] S4. After the required vacuum level for the test is reached after the second time T2, the molecular pump is turned off;

[0045] S5. Open the first shut-off valve to allow the gas to be tested to enter the cold trap test chamber unit, and measure the parameters of the gas to be tested through the MEMS gas sensor;

[0046] S6. Test completed. Turn off the gas testing device and wait for the next gas test.

[0047] Based on the above technical solution, preferably, in step S2, the relationship between the vacuum degree P of the cold trap test chamber unit and the first time T1 is as follows:

[0048]

[0049] The first time T1 ranges from [0, +∞), and the limit (minimum) of vacuum P is 1 Pa.

[0050] Based on the above technical solution, preferably, in step S4, the relationship between the vacuum degree P of the cold trap test chamber unit and the second time T2 is as follows:

[0051]

[0052] The second time T2 ranges from [0, +∞), and the limit (minimum) of the vacuum degree P is 10. -5 Pa.

[0053] The gas testing apparatus and method for simulating low-temperature vacuum environments of the present invention have the following advantages over the prior art:

[0054] (1) A low vacuum is first drawn and pressure is maintained by a vacuum pump unit to remove water vapor from the cold trap test chamber unit. Then the cold trap is turned on to cool the inside of the cold trap test chamber unit. This not only allows for good heat transfer and makes the internal temperature of the entire cold trap test chamber unit uniform, but also prevents ice formation inside and improves the accuracy of the test. After the internal temperature drops to a specific temperature (the temperature required for gas testing), the vacuum pump unit is used to draw a specific vacuum (the high vacuum required for gas testing). Finally, the gas to be tested (such as H2S) is introduced to achieve accurate measurement of the parameters of the gas to be tested in a low-temperature vacuum environment.

[0055] (2) Unlike the low temperature and normal pressure test device, the gas to be tested is first injected into the gas buffer chamber through the rubber stopper seal (such as by injecting with a syringe). When the vacuum degree in the cold trap test chamber unit reaches the experimental set value, the gas buffer chamber is then introduced into the cold trap test chamber unit. This can ensure the vacuum degree and improve the measurement accuracy.

[0056] (3) By assembling a set of resistance gauges and ionization gauges on the cold trap cover of the cold trap test chamber unit, the resistance gauge is used to test the pressure under low vacuum, while the ionization gauge is used to test the pressure under high vacuum. The pressure measured by the two is displayed on the vacuum gauge in real time. Resistance gauges and ionization gauges are respectively installed on the mechanical pump and molecular pump of the vacuum pump unit so as to monitor the vacuum degree of the mechanical pump and molecular pump in real time, thereby achieving the purpose of protecting the resistance gauges and ionization gauges on the cold trap cover. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 This is a schematic diagram of the gas testing device module for simulating a low-temperature vacuum environment according to the present invention;

[0059] Figure 2 This is a structural diagram of the intake unit of the present invention;

[0060] Figure 3 This is a structural diagram of the cold trap cover of the present invention;

[0061] Figure 4 This is a flowchart of the gas testing method for simulating a low-temperature vacuum environment according to the present invention. Detailed Implementation

[0062] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0063] Example 1

[0064] like Figure 1 As shown, the present invention provides a gas testing device for simulating a low-temperature vacuum environment, wherein the device comprises:

[0065] Vacuum pump unit, cold trap test chamber unit, air intake unit, testing unit, and monitoring unit;

[0066] The vacuum pump unit is connected to the cold trap test chamber unit and is used to evacuate the cold trap test chamber unit and adjust the vacuum level of the cold trap test chamber unit.

[0067] The cold trap test cavity unit is used to cool the interior of the cold trap test cavity unit using a cold trap, thereby adjusting the internal temperature of the cold trap test cavity unit.

[0068] The air intake unit is connected to the cold trap test chamber unit and is used to transmit the gas to be tested to the cold trap test chamber unit.

[0069] The test unit is connected to the cold trap test chamber unit and is used to measure the parameters of the gas to be tested in the cold trap test chamber unit.

[0070] The monitoring unit is electrically connected to the vacuum pump unit and the cold trap test chamber unit, and is used to monitor the vacuum level of the vacuum pump unit and the vacuum level of the cold trap test chamber unit.

[0071] This device employs a vacuum pump unit to first create a low vacuum and maintain pressure, aiming to remove water vapor from the cold trap test chamber unit. Then, the cold trap is activated to cool the interior of the cold trap test chamber unit. This process ensures good heat transfer, maintaining a uniform temperature throughout the unit and preventing icing, thus improving test accuracy. Once the internal temperature reaches a specific level (required for gas testing), the vacuum pump unit is used to create a specific vacuum level (required for gas testing). Finally, the gas to be tested (such as H2S) is introduced, enabling precise measurement of the gas parameters under low-temperature vacuum conditions.

[0072] The vacuum pump unit includes a mechanical pump and a molecular pump;

[0073] The mechanical pump is connected to the molecular pump via a bellows;

[0074] The molecular pump is connected to the cold trap test chamber unit via a suction baffle valve.

[0075] First, turn on the mechanical pump to evacuate the cold trap test chamber unit to approximately 1 Pa. Then, turn on the cold trap to cool it down. Once the appropriate temperature is reached, turn on the molecular pump to further reduce the vacuum level inside the cold trap test chamber unit to 10. -5 Pa achieves a two-step vacuuming process—low vacuum followed by high vacuum—through a combination of mechanical and molecular pumps, with a cold trap used for cooling in between, thus enabling accurate simulation of a low-temperature vacuum environment.

[0076] The air intake unit includes a first adapter 1, a first shut-off valve 2, a second adapter 3, a gas buffer chamber 4, a third adapter 5, a second shut-off valve 6, a fourth adapter 7, and a rubber stopper seal 8.

[0077] One end of the first shut-off valve 2 is connected to the cold trap test chamber unit through the first adapter 1, and the other end is connected to one end of the gas buffer chamber 4 through the second adapter 3.

[0078] One end of the second shut-off valve 6 is connected to the other end of the gas buffer chamber 4 through the third adapter 5, and the other end is connected to one end of the rubber stopper seal 8 through the fourth adapter 7.

[0079] like Figure 2 As shown, the air intake unit is composed of a first shut-off valve 2, a gas buffer chamber 4, a second shut-off valve 6, and a rubber stopper seal 8, all connected by an adapter. Unlike the low-temperature atmospheric pressure testing device, this device first injects the gas to be tested into the gas buffer chamber 4 through the rubber stopper seal 8 (e.g., using a syringe). Once the vacuum level in the cold trap testing chamber unit reaches the experimentally set value, the gas is then introduced into the cold trap testing chamber unit from the gas buffer chamber 4. This method effectively ensures the vacuum level and improves measurement accuracy. The specific operation is as follows: Open the first shut-off valve 2 and the second shut-off valve 6, turn on the mechanical pump, and after a period of time (e.g., 30 seconds), close the first shut-off valve 2 to bring the gas buffer chamber 4 into a certain vacuum state; then insert the syringe containing the gas to be tested into the rubber stopper seal 8. At this time, the gas to be tested in the syringe will be quickly drawn into the gas buffer chamber 4. Immediately close the second shut-off valve 6, and the gas to be tested will be sealed in the gas buffer chamber 4; when the vacuum degree in the cold trap test chamber unit reaches the experimental set value, open the first shut-off valve 2, and the gas to be tested enters the cold trap test chamber unit (since the volume of the gas buffer chamber 4 (φ25mm×30mm) is very small relative to the cold trap test chamber unit, the influence on the vacuum degree in the cold trap test chamber unit can be ignored), and the gas-sensitive response process begins immediately.

[0080] The test unit includes a MEMS gas sensor and a resistance tester;

[0081] The MEMS gas sensor is connected to the cold trap test chamber unit;

[0082] The resistance tester is electrically connected to the MEMS gas sensor and is used to receive measurement data and output measurement results.

[0083] The MEMS gas sensor is inserted into the cold trap test chamber unit to measure the resistance of the gas to be tested entering the cold trap test chamber unit. The resistance measurement range is 1Ω to 10GΩ.

[0084] The cold trap test chamber unit includes a cold trap cavity, a cold trap cover, a cold trap temperature controller, a temperature sensor, and a display.

[0085] The cold trap cavity is sealed to the cold trap cover;

[0086] The cold trap cover is connected to the vacuum pump unit, the air inlet unit, the testing unit, and the monitoring unit, respectively.

[0087] The cold trap temperature controller is located outside the cold trap cavity and is used to adjust the temperature of the inner wall of the cold trap cavity;

[0088] The temperature sensor is located around the test unit and is used to measure the temperature near the test unit;

[0089] The display is located outside the cold trap cavity and is used to display the temperature of the inner wall of the cold trap cavity and the temperature near the test unit.

[0090] The cold trap test chamber unit includes a cold trap cavity, a cold trap cover, a cold trap temperature controller, a temperature sensor, and a display. The cold trap volume (i.e., the test chamber volume) is 4L, with internal dimensions of φ160mm × 200mm and external dimensions of W360mm × D600mm × H300mm. The display shows the temperature of the inner wall of the cavity and the temperature of the PT100 temperature sensor located adjacent to the MEMS gas sensor. The real-time temperature displayed on the display ensures a consistent internal temperature throughout the cold trap test chamber unit. To ensure the airtightness of the test chamber, the PT100 temperature sensor and the display are connected via an aviation connector.

[0091] The monitoring unit includes a first resistance gauge, a second resistance gauge, a first ionization gauge, and a second ionization gauge.

[0092] The first resistance gauge is connected to the mechanical pump and is used to monitor the vacuum level of the mechanical pump;

[0093] The first ionization gauge is connected to the molecular pump and is used to monitor the vacuum level of the molecular pump;

[0094] The second resistance gauge is connected to the cold trap cover and is used to monitor the vacuum level of the cold trap cavity when the mechanical pump is working;

[0095] The second ionization gauge is connected to the cold trap cover and is used to monitor the vacuum level of the cold trap cavity when the molecular pump is working.

[0096] The cold trap test chamber unit is equipped with a set of resistance gauges and ionization gauges on its cold trap cover. The resistance gauge is used to test the pressure under low vacuum, while the ionization gauge is used to test the pressure under high vacuum. The pressure measured by both is displayed on the vacuum gauge in real time. The mechanical pump and molecular pump of the vacuum pump unit are equipped with resistance gauges and ionization gauges respectively, so as to monitor the vacuum level of the mechanical pump and molecular pump in real time, thereby protecting the resistance gauges and ionization gauges on the cold trap cover.

[0097] The cold trap cover includes a first channel 9, a second channel 10, a third channel 11, a fourth channel 12, a fifth channel 13, and a sixth channel 14.

[0098] The first channel 9 is used to connect to the air intake unit;

[0099] The second channel 10 is used to connect the second resistor gauge;

[0100] The third channel 11 is used as a backup channel;

[0101] The fourth channel 12 is used to connect the molecular pump through the suction baffle valve;

[0102] The fifth channel 13 is used to connect the test unit via an air connector;

[0103] The sixth channel 14 is used to connect to the second ionization gauge;

[0104] The first channel 9, the second channel 10, the third channel 11, the fourth channel 12, the fifth channel 13 and the sixth channel 14 are staggered on the cold trap cover.

[0105] The most important and also the most precise part of the cold trap test chamber unit is the cold trap cover on top of the cold trap chamber. For example... Figure 3As shown (where (a) is a perspective view, (b) is a top view, and (c) is a front view), there are a total of 10 holes on the top of the cold trap cover. The four holes closest to the outer edge of the cold trap cover are screw holes, which seal the cold trap cover to the cold trap cavity. The interface sizes of the six smaller holes in the middle are: three KF16, two KF40, and one KF25. The central KF16 port is used to connect to the air intake unit, another KF16 port is used to connect to the resistance gauge, and the last KF16 port serves as a spare outlet. Two KF40 ports are used to connect the suction baffle valve and the aviation connector, respectively. The suction baffle valve is connected to the vacuum pump unit via a bellows. The aviation connector is a 9-pin connector; the side facing the cold trap cavity is soldered with the test electrodes of the PT100 temperature sensor and the MEMS gas sensor, while the side facing away from the cold trap cavity is soldered with DuPont wires to connect the alligator clips of the display and the Keithley 6487 picoammeter (or a USB data transfer cable directly to the computer). One KF25 port connects to the ionization gauge. The varying heights of the protruding connecting tubes from each port are to allow for staggered installation of clamps within the limited space.

[0106] The gas testing device in this embodiment can generate specific extreme environments, including specific temperatures and specific vacuum levels. Once the cold trap cavity within the device reaches a low temperature and a high vacuum level (extreme environment), the gas to be tested enters the cold trap cavity through the inlet unit. The MEMS gas sensor is also placed inside the cold trap cavity. Thus, the MEMS gas sensor can detect the parameters of the gas to be tested under the simulated low-temperature vacuum environment of the cold trap cavity, ensuring measurement accuracy. This gas testing device can lower the temperature inside the cold trap cavity to -50°C and achieve a vacuum level of 1×10⁻⁶. -5 Pa, resistance measurement range is 1Ω~10GΩ.

[0107] Example 2

[0108] like Figure 4 As shown, a gas testing method simulating a low-temperature vacuum environment is provided, which uses the gas testing device simulating a low-temperature vacuum environment as described in Example 1, and includes the following steps:

[0109] S1. Open the vacuum baffle valve, the first shut-off valve 2 and the second shut-off valve 6, then turn on the mechanical pump to evacuate the cold trap test chamber unit, and start timing at the same time;

[0110] S2. After a certain vacuum level is reached in the first time T1, the mechanical pump and the first shut-off valve 2 are turned off. Then, the syringe containing the gas to be tested is injected into the gas buffer chamber 4 through the rubber stopper seal 8. After the injection is completed, the second shut-off valve 6 is turned off.

[0111] S3. Turn on the cold trap to cool the inside of the cold trap test chamber unit. When the display shows that the temperature of the inner wall of the cold trap chamber and the temperature near the test unit have reached the required test temperature, maintain the temperature through the cold trap temperature controller, and at the same time turn on the molecular pump to evacuate the cold trap test chamber unit and restart the timing.

[0112] S4. After the required vacuum level for the test is reached after the second time T2, the molecular pump is turned off;

[0113] S5. Open the first shut-off valve 2 to allow the gas to be tested to enter the cold trap test chamber unit, and measure the parameters of the gas to be tested through the MEMS gas sensor;

[0114] S6. Test completed. Turn off the gas testing device and wait for the next gas test.

[0115] This method first uses a mechanical pump to create a low vacuum (approximately 1 Pa) and maintain the pressure to remove water vapor from the cold trap test chamber unit. Then, the cold trap is activated to cool the interior of the unit. This process ensures good heat transfer, maintaining a uniform temperature throughout the unit and preventing icing, thus improving test accuracy. Once the internal temperature reaches a specific level (the temperature required for gas testing, such as -50°C), a molecular pump is used to create a specific vacuum (the high vacuum required for gas testing, such as 10...). -5 Pa), and finally the gas to be measured (such as H2S) is introduced to achieve accurate measurement of the parameters of the gas to be measured in a low-temperature vacuum environment.

[0116] In step S2, the relationship between the vacuum level P of the cold trap test chamber unit and the first time T1 is as follows:

[0117]

[0118] The first time T1 ranges from [0, +∞), and the limit (minimum) of vacuum P is 1 Pa.

[0119] In step S4, the relationship between the vacuum level P of the cold trap test chamber unit and the second time T2 is as follows:

[0120]

[0121] The second time T2 ranges from [0, +∞), and the limit (minimum) of the vacuum degree P is 10. -5 Pa.

[0122] It should be noted that since the molecular pump can only start working after the mechanical pump has reduced the gas pressure in the cold trap test chamber unit to 1 Pa, the vacuum degree P ≈ 1 Pa when the second time T2 = 0.

[0123] The gas testing method in this embodiment can generate specific extreme environments, including specific temperatures and specific vacuum levels. When the cold trap cavity in the gas testing device reaches a low temperature and a high vacuum level (extreme environment), the gas to be tested enters the cold trap cavity through the gas inlet unit. The MEMS gas sensor is also placed inside the cold trap cavity. In this way, the MEMS gas sensor can detect the parameters of the gas to be tested in the low-temperature vacuum environment simulated by the cold trap cavity, ensuring measurement accuracy.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gas testing device simulating a low-temperature vacuum environment, characterized in that: The device includes: Vacuum pump unit, cold trap test chamber unit, air intake unit, testing unit, and monitoring unit; The vacuum pump unit is connected to the cold trap test chamber unit and is used to evacuate the cold trap test chamber unit and adjust the vacuum level of the cold trap test chamber unit. The cold trap test cavity unit is used to cool the interior of the cold trap test cavity unit using a cold trap, thereby adjusting the internal temperature of the cold trap test cavity unit. The air intake unit is connected to the cold trap test chamber unit and is used to transmit the gas to be tested to the cold trap test chamber unit. The test unit is connected to the cold trap test chamber unit and is used to measure the parameters of the gas to be tested in the cold trap test chamber unit. The monitoring unit is electrically connected to the vacuum pump unit and the cold trap test chamber unit, and is used to monitor the vacuum level of the vacuum pump unit and the vacuum level of the cold trap test chamber unit. The vacuum pump unit includes a mechanical pump and a molecular pump; The mechanical pump is connected to the molecular pump via a bellows; The molecular pump is connected to the cold trap test chamber unit via a suction baffle valve. The intake unit includes a first adapter (1), a first shut-off valve (2), a second adapter (3), a gas buffer chamber (4), a third adapter (5), a second shut-off valve (6), a fourth adapter (7), and a rubber stopper seal (8). One end of the first shut-off valve (2) is connected to the cold trap test chamber unit through the first adapter (1), and the other end is connected to one end of the gas buffer chamber (4) through the second adapter (3); One end of the second shut-off valve (6) is connected to the other end of the gas buffer chamber (4) through the third adapter (5), and the other end is connected to one end of the rubber stopper seal (8) through the fourth adapter (7); The cold trap test chamber unit includes a cold trap chamber, a cold trap cover, a cold trap temperature controller, a temperature sensor, and a display. The cold trap cavity is sealed to the cold trap cover; The cold trap cover is connected to the vacuum pump unit, the air inlet unit, the testing unit, and the monitoring unit, respectively. The cold trap temperature controller is located outside the cold trap cavity and is used to adjust the temperature of the inner wall of the cold trap cavity; The temperature sensor is located around the test unit and is used to measure the temperature near the test unit; The display is located outside the cold trap cavity and is used to display the temperature of the inner wall of the cold trap cavity and the temperature near the test unit; The monitoring unit includes a first resistance gauge, a second resistance gauge, a first ionization gauge, and a second ionization gauge; The first resistance gauge is connected to the mechanical pump and is used to monitor the vacuum level of the mechanical pump; The first ionization gauge is connected to the molecular pump and is used to monitor the vacuum level of the molecular pump; The second resistance gauge is connected to the cold trap cover and is used to monitor the vacuum level of the cold trap cavity when the mechanical pump is working; The second ionization gauge is connected to the cold trap cover and is used to monitor the vacuum level of the cold trap cavity when the molecular pump is working.

2. The gas testing device for simulating a low-temperature vacuum environment as described in claim 1, characterized in that: The testing unit includes a MEMS gas sensor and a resistance tester; The MEMS gas sensor is connected to the cold trap test chamber unit; The resistance tester is electrically connected to the MEMS gas sensor and is used to receive measurement data and output measurement results.

3. The gas testing device for simulating a low-temperature vacuum environment as described in claim 1, characterized in that: The cold trap cover includes a first channel (9), a second channel (10), a third channel (11), a fourth channel (12), a fifth channel (13), and a sixth channel (14). The first channel (9) is used to connect the air intake unit; The second channel (10) is used to connect the second resistor gauge; The third channel (11) is used as a backup channel; The fourth channel (12) is used to connect the molecular pump through the suction baffle valve; The fifth channel (13) is used to connect the test unit via an air plug; The sixth channel (14) is used to connect to the second ionization gauge; The first channel (9), the second channel (10), the third channel (11), the fourth channel (12), the fifth channel (13) and the sixth channel (14) are staggered on the cold trap cover.

4. A gas testing method for a gas testing device simulating a low-temperature vacuum environment as described in any one of claims 1-3, characterized in that: Includes the following steps: S1. Open the vacuum baffle valve, the first shut-off valve (2) and the second shut-off valve (6), then turn on the mechanical pump to evacuate the cold trap test chamber unit, and start timing at the same time; S2. After the vacuum reaches a certain level in the first time T1, the mechanical pump and the first shut-off valve (2) are closed. Then, the syringe containing the gas to be tested is injected into the gas buffer chamber (4) through the rubber stopper seal (8). After the injection is completed, the second shut-off valve (6) is closed. S3. Turn on the cold trap to cool the inside of the cold trap test chamber unit. When the display shows that the temperature of the inner wall of the cold trap chamber and the temperature near the test unit have reached the required test temperature, maintain the temperature through the cold trap temperature controller, and at the same time turn on the molecular pump to evacuate the cold trap test chamber unit and restart the timing. S4. After the required vacuum level for the test is reached after the second time T2, the molecular pump is turned off; S5. Open the first shut-off valve (2) to allow the gas to be tested to enter the cold trap test chamber unit and measure the parameters of the gas to be tested through the MEMS gas sensor; S6. Test completed. Turn off the gas testing device and wait for the next gas test.

5. The gas testing method as described in claim 4, characterized in that: In step S2, the relationship between the vacuum level P of the cold trap test chamber unit and the first time T1 is as follows: ； The first time T1 ranges from [0, +∞), and the minimum value of vacuum P is 1 Pa.

6. The gas testing method as described in claim 4, characterized in that: In step S4, the relationship between the vacuum level P of the cold trap test chamber unit and the second time T2 is as follows: ； The second time T2 ranges from [0, +∞), and the minimum value of the vacuum degree P is 10. -5 Pa.

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