An automated control calibration method and system for a confined space gas measurement device

Abstract

The application provides an automatic control calibration method and system for a closed space gas measuring device, and the system comprises a host computer, a high-low temperature test box, a pressure controller, a calibration tool for providing a closed test environment, a data acquisition card and a gas measuring device to be calibrated. The calibration method of the application is as follows: after the host computer reads the configuration parameters, the high-low temperature test box changes the temperature at a fixed rate, and when the temperature in the tool reaches the lower threshold point of the target temperature, the pressure calibration process at this temperature point is triggered; then, the host computer controls the pressure controller to adjust the total pressure in sequence according to the configuration parameters, and ensures that the total pressure is recorded under the steady state by continuously monitoring the pressure stability mark; after completing the current concentration calibration process, the gas cylinder is replaced, and the system automatically controls the execution of the purging process to replace the residual gas in the closed tool; finally, the host computer automatically calculates the device accuracy, and the actual measurement is read back for verification. The application significantly improves the calibration test efficiency and accuracy.

Description

Technical Field

[0001] This invention relates to the field of measurement and testing technology, and specifically to an automated control calibration method and system for a gas measurement device in a confined space. Background Technology

[0002] Gas measurement equipment is a crucial component for maintaining life safety and ensuring core production in confined environments such as aerospace cabins, deep-sea submersibles, underground mines, and sealed industrial reactors. In these environments, air circulation is extremely limited, and even minute changes in gas concentration can trigger irreversible and catastrophic consequences. Therefore, gas measurement equipment used in confined environments requires extremely high measurement accuracy.

[0003] To ensure the reliability of gas measuring equipment under extreme environmental conditions, rigorous calibration tests are required before shipment or during routine maintenance. The calibration process typically needs to be performed in a confined space using a combination of multiple temperatures, total pressures, and different gas concentrations. Current calibration technologies mainly face the following challenges and limitations: (1) During the calibration process, key steps such as adjusting temperature, adjusting pressure, data acquisition, and data processing rely heavily on manual labor. In the face of scenarios involving the cross-calibration of multiple parameters, manual labor is prone to errors and has a large workload. (2) When performing multi-temperature point traversal, the traditional method usually adopts stepped temperature control: that is, after setting the temperature chamber to a certain temperature, it is necessary to wait for the entire temperature chamber and internal equipment to be completely still and stable before starting the pressure test. This method faces problems such as low efficiency and long time consumption.

[0004] (3) When switching between different concentrations of gas during calibration, traditional processes often use continuous positive pressure purging. However, in a fully enclosed calibration fixture, single positive pressure purging can easily create dead zones in the airflow, and residual gas can cause cross-contamination, leading to inaccurate results and poor precision.

[0005] Therefore, there is a need for a method and system that can perform gas calibration efficiently and with high precision. Summary of the Invention

[0006] This invention addresses the problems of low efficiency, long processing time, residual gas in confined spaces, and poor accuracy in existing gas calibration methods. It provides an automated control calibration method and system for confined space gas measuring equipment. The system includes a host computer, a high and low temperature test chamber, a pressure controller, calibration fixtures providing a confined testing environment, a data acquisition card, and the gas measuring equipment to be calibrated. The calibration method is as follows: After the host computer reads the configuration parameters, the high and low temperature test chamber changes temperature at a fixed rate. When the temperature inside the fixture reaches the lower threshold of the target temperature, a pressure calibration process at that temperature is triggered. Subsequently, the host computer controls the pressure controller to adjust the total pressure sequentially according to the configuration parameters, continuously monitoring the pressure stability indicator to ensure the total pressure remains stable and recording test data. After completing the current concentration calibration process, the gas cylinder is replaced, and the system automatically controls a purging process to replace the residual gas in the confined fixture. Finally, the host computer automatically calculates the equipment accuracy, and the actual measurement is read back for verification. This invention significantly improves the efficiency and accuracy of calibration testing.

[0007] This invention provides an automated control calibration method and system for a gas measurement device in a confined space, comprising the following steps: S1. Establish an automated control and calibration system for gas measurement equipment in a confined space and set the calibration parameters in the configuration file; The automated control and calibration system for gas measurement equipment in a confined space includes a host computer, a data acquisition card, a high and low temperature test chamber, calibration fixtures, gas measurement equipment to be calibrated, a DC power supply, a pressure controller, a gas pump, and standard gas cylinders. When the host computer starts up, it reads the calibration parameters from the configuration file. The calibration parameters include an array of target temperature values. Target total pressure array Threshold array at temperature Temperature threshold array The number of purging cycles and the pressure stabilization time t are given, where m and n are integers greater than 2, and T is a constant. Set the lowest temperature of the high and low temperature test chamber. and highest temperature , , ; S2. Begin calibration. The high and low temperature test chamber will operate at a fixed temperature rise rate. During continuous operation, the host computer collects the temperature values ​​of the internal temperature sensor of the gas measuring device to be calibrated in real time through the data acquisition card. i Initialize to 1; S3, when the temperature reaches When the target temperature point corresponding to the lower threshold point is triggered. The total pressure control calibration process proceeds to step S4; S4, Upper computer controls pressure controller (press) The pressure sequence in Within the temperature range, the total pressure inside the calibration fixture is adjusted sequentially, and the calibration data is automatically recorded after the total pressure stabilizes for time t. when After the total pressure calibration is completed within the entire temperature range, the host computer will mark it. Temperature is now complete; Return to step S3 until the total pressure calibration process for all target temperature values ​​under the same gas concentration is completed, and the host computer communicates with the pressure controller. S5. After the current gas concentration has completed the cycle of all target temperature points and total pressure points, the host computer outputs a prompt to indicate the replacement of standard gas. After detecting the gas replacement confirmation signal, the purging process is started. After the purging is completed, the process returns to step S2 until all gas concentrations are calibrated. S6. The host computer automatically calculates the measurement accuracy of the gas measuring equipment to be calibrated.

[0008] The present invention discloses an automated control calibration method and system for a gas measuring device in a confined space. In a preferred embodiment, in step S1, there are at least two gas measuring devices to be calibrated, both of which are set in the same calibration fixture. Each gas measuring device to be calibrated is connected to a data acquisition card and a DC power supply. All gas measuring devices to be calibrated are calibrated simultaneously. The calibration parameters also include the number of gas measuring devices to be calibrated.

[0009] In the preferred embodiment of the automated control calibration method and system for a gas measuring device in a confined space described in this invention, in step S2, the host computer collects the temperature values ​​of all internal temperature sensors of the gas measuring device to be calibrated in real time through a data acquisition card, and calculates the average temperature. In step S3, when the average temperature reaches When the target temperature point corresponding to the lower threshold point is triggered. Total pressure control calibration process.

[0010] The automated control calibration method and system for a gas measuring device in a confined space described in this invention, as a preferred embodiment, in step S2, .

[0011] The automated control calibration method and system for a gas measuring device in a confined space according to the present invention, in a preferred embodiment, in step S4, the host computer sends a control command to the pressure controller and sequentially adjusts the total pressure in the calibration fixture to the target total pressure value array. During the pressure regulation process, the internal pressure value of the calibration fixture and the pressure stability indicator transmitted back by the pressure controller are continuously monitored; a pressure stability indicator of 1 indicates that the pressure is stable, and a pressure stability indicator of 0 indicates that the pressure is not stable. When the host computer receives the pressure stabilization signal for the first time, it starts timing. When the cumulative duration of continuous stabilization reaches the pressure stabilization duration t, the collected gas concentration calibration data of the gas measuring device to be calibrated is recorded locally. If the continuous stable cumulative time has not reached the pressure stabilization time t, but the host computer receives a pressure stabilization signal, the host computer will reset the continuous stable cumulative time to zero until the continuous stable cumulative time reaches the pressure stabilization time t before collecting calibration data.

[0012] The automated control calibration method and system for a gas measuring device in a confined space, as described in this invention, preferably uses a pressure controller with a pressure control accuracy greater than that of the gas measuring device to be calibrated.

[0013] In the preferred embodiment of the automated control calibration method and system for a gas measurement device in a confined space described in this invention, in step S4, the host computer communicates with the pressure controller to transmit calibration data, which includes timestamp, target temperature value, target total pressure value, gas type, gas concentration, temperature value measured by the temperature sensor, and total pressure value measured.

[0014] The automated control calibration method and system for a gas measuring device in a confined space according to the present invention, in a preferred embodiment, the purging process in step S5 is as follows: the host computer controls the pressure controller and the gas circuit valve to draw the total pressure in the calibration fixture to a negative pressure lower than the standard atmospheric pressure, and then fills it with gas to a positive pressure higher than the standard atmospheric pressure. The above-mentioned evacuation-filling action is repeated until the number of purging cycles is reached to replace the residual gas of the previous concentration in the fixture.

[0015] The present invention discloses an automated control calibration method and system for a gas measuring device in a confined space. In a preferred embodiment, the automated control calibration system for the gas measuring device in a confined space consists of a host computer, a data acquisition card, and the gas measuring device to be calibrated connected in sequence. The host computer manages parameters, processes, records data, and coordinates equipment; it controls the pressure controller to adjust the gas environment inside the calibration fixture, and receives the output of the gas measuring device to be calibrated from the data acquisition card. The calibration fixture houses the gas measuring device to be calibrated and provides a closed gas testing environment. The calibration fixture is connected to the pressure controller and is equipped with a power supply interface and a gas path interface. The high and low temperature test chamber contains calibration fixtures and provides a sealed variable temperature environment.

[0016] The automated control calibration method and system for a gas measuring device in a confined space described in this invention, in a preferred embodiment, involves the host computer communicating with the pressure controller via an RS232 serial port. The DC power supply is connected to the gas measuring device to be calibrated and provides power output; Under the control of the host computer and pressure controller, the gas replacement device discharges or fills gas into the calibration fixture. The gas replacement device includes an air pump, a standard gas cylinder and pipeline valves. The output interface of the pressure controller is connected to the calibration fixture, the positive input interface is connected to the standard gas cylinder, and the negative input interface is connected to the air pump. The pressure controller monitors and adjusts the gas environment inside the calibration fixture.

[0017] This invention provides an automated control calibration method and system for a gas measurement device in a confined space. The system mainly includes a host computer, a high and low temperature test chamber, a pressure controller, calibration fixtures providing a confined testing environment, a data acquisition card, and a gas replacement device. The calibration method is as follows: After the host computer reads the configuration parameters, the high and low temperature test chamber changes temperature at a fixed rate. When the temperature inside the fixture reaches the lower threshold of the target temperature, a pressure calibration process at that temperature is triggered. Subsequently, the host computer controls the pressure controller to adjust the total pressure sequentially according to the configuration parameters, and continuously monitors the pressure stability flag to ensure the total pressure remains stable and records test data. After completing the current concentration calibration process, the gas cylinder is replaced, and the system automatically controls the purging process to replace the residual gas in the confined fixture. Finally, the host computer automatically calculates the equipment accuracy and verifies it by reading back from the actual measurement. The technical effects achieved by this invention are: reduced manual workload, reduced possibility of human error, improved calibration testing efficiency and accuracy, and provision of a verification method.

[0018] This invention establishes an automated control system for gas measurement equipment in confined spaces through a host computer coordinating a high and low temperature test chamber, a pressure controller, a data acquisition card, and a gas replacement device. This system enables multi-parameter collaborative calibration. The host computer can read the configuration file with a single click, automatically execute the calibration process, monitor equipment status, perform the purging process, and synchronously collect and record calibration data. This invention can monitor the temperature value during the temperature rise process of the gas measurement equipment and compare it in real time with the threshold value at the target temperature. It also records steady-state data under the pressure instability flag zeroing and reset mechanism, ensuring the effectiveness of data acquisition. Simultaneously, during the switching phase between different gas concentrations, it resets the gas concentration within the confined calibration fixture by alternately executing a cyclic purging process of negative pressure below standard atmospheric pressure and positive pressure above standard atmospheric pressure. After the entire calibration process is completed, it automatically calculates the fitting equipment accuracy, performs real-time readback and equipment accuracy verification, and synchronously saves the equipment accuracy to the local storage. This invention establishes an automated control system for gas measurement equipment in confined spaces through a host computer coordinating a high and low temperature test chamber, a pressure controller, a data acquisition card, and a gas replacement device. This system enables collaborative calibration of multiple parameters. The host computer can read the configuration file with a single click, automatically executing the calibration process, monitoring equipment status, performing the purging process, and synchronously acquiring and recording calibration data. This invention can monitor the temperature value during the temperature rise process of the gas measurement equipment and compare it in real time with the threshold value at the target temperature. It also records steady-state data under the pressure instability flag zeroing and reset mechanism, ensuring the effectiveness of data acquisition. Simultaneously, during the switching phase between different gas concentrations, it resets the gas concentration within the confined calibration fixture by alternately executing a cyclic purging process of negative pressure below standard atmospheric pressure and positive pressure above standard atmospheric pressure. After the entire calibration process is completed, it automatically calculates the fitting equipment accuracy, performs real-time readback and equipment accuracy verification, and synchronously saves the equipment accuracy to the local storage.

[0019] The present invention has the following advantages: (1) This invention manages parameters, processes, records data and coordinates equipment in the calibration process through a host computer. The unattended mode is easy to operate and transforms the repetitive work of manually adjusting the pressure and observing the steady state into one-click automated operation driven by parameter configuration. This makes the calibration process more standardized and efficient. In the face of multi-parameter cross-calibration scenarios, it further liberates manpower, reduces the workload of manpower and reduces the possibility of errors caused by human error. (2) This invention performs automated pressure control and data acquisition, and introduces a timing mechanism for resetting and zeroing when the pressure is unstable, ensuring that all calibration data are acquired under the steady-state pressure of the closed space where the gas measuring equipment is located, thus avoiding errors caused by minor leaks or disturbances. (3) This invention improves the efficiency of calibration testing, breaks the long stagnation and waiting of traditional stepped temperature control, accurately triggers the total pressure calibration process in the dynamic process of fixed temperature rise rate, and greatly shortens the cycle of multi-dimensional test matrix; (4) The gas purging process of the present invention utilizes the breathing purging technology of alternating negative and positive pressure to remove residual high-concentration gas in the dead corner of the sealed calibration fixture, thereby reducing cross-contamination between multiple concentration tests. (5) The data processing and effect verification of the present invention automatically calculates the equipment accuracy after the collected data is recorded by the host computer software, and then performs back reading verification, which can effectively evaluate the equipment accuracy and realize intelligent analysis of the performance of gas measurement equipment in closed space. (6) This invention reduces the average working hours per person for a single calibration task to 1 / 10 of the original, significantly improving the overall output efficiency of the team. Attached Figure Description

[0020] Figure 1A flowchart of an automated control calibration method for a gas measurement device in a confined space; Figure 2 This is a schematic diagram of the system structure of an automated control calibration method for a gas measurement device in a confined space.

[0021] Figure label: 1. Host computer; 2. Data acquisition card; 3. High and low temperature test chamber; 4. Calibration fixture; 5. Gas measuring equipment to be calibrated; 6. DC power supply; 7. Pressure controller; 8. Air pump; 9. Standard gas cylinder. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example 1

[0023] like Figures 1-2 As shown, an automated control calibration method and system for a gas measuring device in a confined space is disclosed. The automated control calibration method for the gas measuring device in a confined space includes the following steps: S1. Build an automated control calibration system for gas measurement equipment in a closed space, set the calibration parameters in the configuration file, and the host computer (1) reads the preset calibration parameters in the configuration file when it starts.

[0024] In this embodiment, the calibration parameters include: number of devices to be calibrated (5 units), target temperature value array (-15℃, -5℃, 5℃, 15℃, 25℃), target total pressure value array (70kPa, 75 kPa, 80 kPa, 85 kPa, 90 kPa, 95 kPa, 100kPa, 105 kPa), temperature threshold array (-17℃, -7℃, 3℃, 13℃, 23℃), temperature upper threshold array (-13℃, -3℃, 7℃, 17℃, 27℃), number of purging cycles (30 times), and pressure stabilization time (120 seconds).

[0025] The initial temperature of the high and low temperature test chamber 3 is lower than the lower threshold point of the lowest temperature point. Calibration begins when the temperature sensor temperature is lower than the lower threshold point of the temperature point.

[0026] In this embodiment, the high and low temperature test chamber 3 is set with a minimum temperature of -20℃ and a maximum temperature of 30℃, and the heating rate of the high and low temperature test chamber 3 is a fixed value of 0.2℃ / min; S2. Start calibration. The high and low temperature test chamber 3 runs continuously at a fixed temperature rise rate. The host computer 1 collects the temperature value of the internal temperature sensor of the gas measuring device 5 to be calibrated in real time through the data acquisition card 2, and judges whether the temperature value has reached the lower threshold of the target temperature point. S3. During the heating process, when the temperature collected by the host computer 1 reaches the lower threshold of the temperature point for the first time, the total pressure control calibration process of the target temperature point is triggered.

[0027] S4. When the lower threshold point of the target temperature point is determined, the calibration process is automatically started. The host computer 1 controls the pressure controller 7 to adjust the total pressure value according to the total pressure value array set in the calibration parameters. After the total pressure is stable, the calibration data is automatically recorded. The specific method is as follows: the pressure control accuracy is greater than that of the gas measuring equipment. After the calibration process is started, the host computer 1 sends a control command to the pressure controller 7 to adjust the total pressure in the calibration fixture 4 to the set value. During the process, the internal pressure value and pressure stability flag of the calibration fixture 4 returned by the pressure controller 7 are continuously monitored. When the pressure stability flag is received for the first time, the timing starts. After the pressure stability time is reached, the calibration data is collected and recorded locally. If the pressure stability time is not reached, the pressure instability flag received by the host computer 1 is reset to zero. The calibration data is collected again after the continuous stability time reaches the pressure stability time.

[0028] Once the total pressure calibration process at a certain target temperature is completed, the host computer 1 marks that temperature as complete, until the total pressure calibration process for all target temperature values ​​at the same gas concentration is completed.

[0029] The host computer 1 communicates with the pressure controller 7, and the calibration data includes timestamp, target temperature value, target total pressure value, gas type, gas concentration, temperature value measured by the temperature sensor, and measured total pressure value.

[0030] S5. After the current gas concentration has completed the cycle of all temperature points and total pressure points, the host computer 1 outputs a prompt to indicate the replacement of the standard gas. After the gas replacement confirmation signal is detected, the purging process is started. After the purging is completed, steps S2 to S4 are repeated until all gas concentrations are calibrated. The purging process is as follows: the host computer 1 controls the pressure controller 7 and related gas circuit valves to draw the total pressure in the calibration fixture 4 to a negative pressure lower than the standard atmospheric pressure, and then fills it with gas to a positive pressure higher than the standard atmospheric pressure. The above purging-filling action is repeated to replace the gas of the previous concentration remaining in the fixture.

[0031] S6. The host computer 1 automatically calculates the accuracy of the gas measuring device to be calibrated and saves it locally. The output analog value of the gas measuring device 5 to be calibrated is converted into the actual environmental measurement value, which can verify the accuracy of the gas measuring device to be calibrated.

[0032] like Figure 1The diagram shown is an automated control calibration system for a gas measuring device in a confined space provided in an embodiment of this application. It includes a host computer 1, a data acquisition card 2, a high and low temperature test chamber 3, a calibration fixture 4, a gas measuring device to be calibrated 5, a DC power supply 6, a pressure controller 7, a gas pump 8, and a standard gas cylinder 9.

[0033] The host computer 1 is the control core of the entire system. It is responsible for parameter management, process management, data recording and equipment coordination of the system calibration process. It communicates with the pressure controller 7 through RS232 serial port and is connected to the data acquisition card 2. It is responsible for controlling the pressure controller 7 to adjust the gas environment inside the calibration fixture 4 and receiving the output of the gas measuring device 5 to be calibrated from the data acquisition card 2. Data acquisition card 2 is used to acquire the analog signal output by the gas measuring device 5 to be calibrated; The high and low temperature test chamber 3 is used to house the calibration fixture 4 and provide a closed variable temperature environment; The calibration fixture 4 is connected to the gas measuring device 5 to be calibrated and the pressure controller 7. It is equipped with a power supply interface and a gas circuit interface. The gas measuring device 5 to be calibrated is placed inside the calibration fixture 4 to provide a closed gas testing environment. DC power supply 6 is connected to gas measuring device 5 to be calibrated, providing a stable power output; data acquisition card 2 acquires the analog signal output by gas measuring device 5 to be calibrated. The gas replacement device includes a gas pump 8, a standard gas cylinder 9, and pipeline valves, which are used to discharge or fill gas into the calibration fixture 4 under the control of the host computer 1 and the pressure controller 7. The output interface of the pressure controller 7 is connected to the calibration fixture 4, the positive input interface is connected to the standard gas cylinder 9, and the negative input interface is connected to the air pump 8, which is used to monitor and adjust the gas environment inside the calibration fixture 4.

[0034] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An automated control calibration method and system for a gas measuring device in a confined space, characterized in that: Includes the following steps: S1. Establish an automated control and calibration system for gas measurement equipment in a confined space and set the calibration parameters in the configuration file; The automated control calibration system of the gas measuring device in the confined space includes a host computer (1), a data acquisition card (2), a high and low temperature test chamber (3), a calibration fixture (4), a gas measuring device to be calibrated (5), a DC power supply (6), a pressure controller (7), a gas pump (8), and a standard gas cylinder (9). When the host computer (1) starts up, it reads the calibration parameters in the configuration file, the calibration parameters including an array of target temperature values. Target total pressure array Threshold array at temperature Temperature threshold array The number of purging cycles and the pressure stabilization time t are given, where m and n are integers greater than 2, and T is a constant. Set the lowest temperature of the high and low temperature test chamber (3). and highest temperature , , ; S2. Calibration begins. The high and low temperature test chamber (3) operates at a fixed temperature rise rate. During continuous operation, the host computer (1) collects the temperature value of the internal temperature sensor of the gas measuring device (5) to be calibrated in real time through the data acquisition card (2); i Initialize to 1; S3, when the temperature reaches When the target temperature point corresponding to the lower threshold point is triggered. The total pressure control calibration process proceeds to step S4; S4, the host computer (1) controls the pressure controller (7) to press The pressure sequence in Within the temperature range, the total pressure value inside the calibration fixture (4) is adjusted sequentially, and the calibration data is automatically recorded after the total pressure stabilizes for a time t. when After the total pressure calibration is completed within the entire temperature range, the host computer (1) marks... Temperature is now complete; Return to step S3 until the total pressure calibration process for all target temperature values ​​under the same gas concentration is completed, and the host computer (1) communicates with the pressure controller (7); S5. After the current gas concentration completes the cycle of all target temperature points and total pressure points, the host computer (1) outputs a prompt to indicate the replacement of standard gas. After detecting the gas replacement confirmation signal, the purging process is started. After the purging is completed, the process returns to step S2 until all gas concentrations are calibrated. S6. The host computer (1) automatically calculates the measurement accuracy of the gas measuring device (5) to be calibrated.

2. The automated control calibration method and system for a gas measuring device in a confined space according to claim 1, characterized in that: In step S1, there are at least two gas measuring devices (5) to be calibrated, both of which are set in the same calibration fixture (4). Each gas measuring device (5) to be calibrated is connected to the data acquisition card (2) and the DC power supply (6). All the gas measuring devices (5) to be calibrated are calibrated at the same time. The calibration parameters also include the number of the gas measuring devices (5) to be calibrated.

3. The automated control calibration method and system for a gas measuring device in a confined space according to claim 2, characterized in that: In step S2, the host computer (1) collects the temperature values ​​of all the internal temperature sensors of the gas measuring device (5) to be calibrated in real time through the data acquisition card (2), and calculates the average temperature. In step S3, when the average temperature reaches When the target temperature point corresponding to the lower threshold point is triggered. Total pressure control calibration process.

4. The automated control calibration method and system for a gas measuring device in a confined space according to claim 1, characterized in that: In step S2, 。 5. The automated control calibration method and system for a gas measuring device in a confined space according to claim 1, characterized in that: In step S4, the host computer (1) sends a control command to the pressure controller (7) and sequentially adjusts the total pressure in the calibration fixture (4) to the target total pressure value array. During the pressure regulation process, the internal pressure value and pressure stability flag of the calibration fixture (4) transmitted back by the pressure controller (7) are continuously monitored; when the pressure stability flag is 1, it indicates that the pressure is stable, and when the pressure stability flag is 0, it indicates that the pressure is not stable. When the host computer (1) receives the pressure stabilization signal for the first time, it starts timing. When the continuous stable cumulative time reaches the pressure stabilization time t, it records the collected gas concentration calibration data output by the gas measuring device (5) to be calibrated locally. When the continuous stable cumulative duration has not reached the pressure stabilization duration t, but the host computer (1) receives a pressure stabilization signal, the host computer (1) will clear the continuous stable cumulative duration to zero until the continuous stable cumulative duration reaches the pressure stabilization duration t before collecting calibration data.

6. The automated control calibration method and system for a gas measuring device in a confined space according to claim 1, characterized in that: The pressure control accuracy of the pressure controller (7) is greater than that of the gas measuring device (5) to be calibrated.

7. The automated control calibration method and system for a gas measuring device in a confined space according to claim 1, characterized in that: In step S4, the host computer (1) communicates with the pressure controller (7) to transmit calibration data, which includes timestamp, target temperature value, target total pressure value, gas type, gas concentration, temperature value measured by temperature sensor and total pressure value measured.

8. The automated control calibration method and system for a gas measuring device in a confined space according to claim 1, characterized in that: The purging process in step S5 is as follows: The host computer (1) controls the pressure controller (7) and the gas valve to draw the total pressure in the calibration fixture (4) to a negative pressure lower than the standard atmospheric pressure, and then fill it with gas to a positive pressure higher than the standard atmospheric pressure. The above purging-filling action is repeated until the number of purging cycles is reached to replace the gas of the previous concentration remaining in the fixture.

9. An automated control calibration method for a gas measuring device in a confined space according to any one of claims 1 to 8, characterized in that: In the automated control calibration system of the gas measuring device in a confined space, the host computer (1), the data acquisition card (2), and the gas measuring device to be calibrated (5) are connected in sequence; The host computer (1) performs parameter management, process management, data recording and equipment coordination; the host computer (1) controls the pressure controller (7) to adjust the gas environment inside the calibration fixture (4); the host computer (1) receives the output of the gas measuring device (5) to be calibrated collected by the data acquisition card (2); The calibration fixture (4) houses the gas measuring device (5) to be calibrated and provides a closed gas testing environment. The calibration fixture (4) is connected to the pressure controller (7) and is equipped with a power supply interface and a gas path interface. The high and low temperature test chamber (3) houses the calibration fixture (4) and provides a sealed variable temperature environment.

10. The automated control calibration method for a gas measuring device in a confined space according to claim 9, characterized in that: The host computer (1) communicates with the pressure controller (7) via an RS232 serial port; The DC power supply (6) is connected to the gas measuring device (5) to be calibrated and provides power output; Under the control of the host computer (1) and the pressure controller (7), the gas replacement device discharges or fills gas into the calibration fixture (4). The gas replacement device includes the air pump (8), the standard gas cylinder (9) and pipeline valves. The output interface of the pressure controller (7) is connected to the calibration fixture (4), the positive input interface is connected to the standard gas cylinder (9), and the negative input interface is connected to the air pump (8). The pressure controller (7) monitors and adjusts the gas environment inside the calibration fixture (4).

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