A gas sensor response time measurement system

Abstract

The utility model provides a kind of gas sensor response time measurement system, to solve the technical problem of poor reliability of the response time measurement result of existing gas sensor.The utility model includes closed circulation device, and the closed circulation device is equipped with the isolated sealing device of containing the gas sensor to be measured, and closed circulation device is connected with gas distribution device and gas concentration monitoring device respectively, and the gas sensor to be measured, isolated sealing device, gas distribution device and gas concentration monitoring device are connected with control unit.The utility model realizes the efficient, accurate measurement of gas sensor response time;And simple structure, reduce manual intervention;Convenient operation, high detection efficiency;Strong universality is applicable to various gas sensors, and can significantly improve industrial calibration and research and development efficiency.

Description

Technical Field

[0001] This utility model relates to the technical field of gas sensors, and in particular to a gas sensor response time measurement system. Background Technology

[0002] In existing technologies, especially for laser gas sensors, response time measurements typically rely on manual operation or non-standardized equipment due to their generally large size and high sensitivity. Traditional methods, such as static chamber testing or open environment exposure, have significant shortcomings: environmental interference (e.g., airflow changes, temperature fluctuations) can lead to concentration instability, affecting measurement accuracy; the operation process is cumbersome, requiring manual recording of time and concentration data, resulting in low efficiency; and different sensor types (e.g., laser, electrochemical, semiconductor, etc.) lack a unified testing platform, leading to poor versatility. These problems result in low reliability of response time measurement results, making it difficult to meet industrial calibration and R&D needs. This invention aims to overcome these shortcomings and provide an automated, high-precision solution.

[0003] Patent application number 201911149162.0 discloses a gas concentration measuring device, which includes at least one gas sensor, a target gas filter, and a gas flow path converter. The device employs an unfiltered mode in the first gas flow path and a quantitative closed-loop filtration mode in the second gas flow path. The filtration effect is not limited by the filter efficiency, effectively extending the service life of the target gas filter. The method uses interval sampling to avoid sensor poisoning failure caused by excessively high concentrations of interfering gases in the measured gas flow, effectively protecting the target gas sensor. To prevent changes in the detection signal value in the filtered mode due to prolonged use, the gas concentration in the measured gas flow is periodically re-detected in the filtered mode to ensure the accuracy of the target gas concentration detection. This invention effectively eliminates the influence of external interference such as interfering gases, sensor drift, and changes in ambient temperature and humidity on gas concentration measurement, resulting in high measurement accuracy, long service life, and fast response speed. However, this patent neglects the measurement of the sensor's dynamic performance (response time). Utility Model Content

[0004] To address the technical problem of poor reliability in the response time measurement results of existing gas sensors, this invention proposes a gas sensor response time measurement system that achieves accurate measurement of response time through closed-loop circulation and intelligent control.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows: a gas sensor response time measurement system includes a closed circulation device, an isolation and sealing device for accommodating the gas sensor to be measured is provided in the closed circulation device, the closed circulation device is connected to a gas distribution device and a gas concentration monitoring device respectively, and the gas sensor to be measured, the isolation and sealing device, the gas distribution device and the gas concentration monitoring device are all connected to a control unit.

[0006] Preferably, the closed-loop circulation device includes a cavity with an air inlet and an air outlet. The air inlet is connected to a gas distribution device, and the air outlet is connected to a gas concentration monitoring device.

[0007] Preferably, the cavity at the positions of the air inlet and air outlet is provided with baffles or grilles to rectify the airflow entering and exiting the cavity, so as to eliminate the influence of airflow on the response time.

[0008] Preferably, both the air inlet and the air outlet are connected to the air pipe via quick-release connectors, and the air pipe is connected to the gas distribution device and the gas concentration monitoring device respectively, which facilitates the connection of the gas distribution device and the gas concentration monitoring device to the air pipe respectively.

[0009] Preferably, the isolation and sealing device is a chamber with a controllable switch, and a gas sensor to be tested is installed inside the chamber; the controllable switch is connected to a control unit; the chamber is connected to a cover through a sealing ring, thereby enabling the gas sensor to be tested to be placed in a sealed state.

[0010] Preferably, the isolation sealing device applies a clamping force through a clamping structure when closed, so that the sealing ring fits tightly against the cabin body, thereby improving the sealing effect of the sealing ring.

[0011] Preferably, the clamping structure includes an annular clamping spring or several leaf springs disposed at the junction of the cover and the cabin. When the cover is closed, the clamping spring or leaf springs are compressed and generate a rebound force, thereby causing the sealing ring to fit against the cabin.

[0012] Preferably, the pressing structure includes a permanent magnet or electromagnet disposed on the edge of the cabin, and an iron block adapted to the permanent magnet or electromagnet is provided on the cover. When closed, the cover is pressed against the cabin by magnetic or electromagnetic force. The permanent magnet or electromagnet is electrically connected to the control unit to achieve synchronous opening and closing.

[0013] Preferably, the clamping structure includes a mechanical latch disposed between the cover and the cabin. The mechanical latch is a cam latch or a wedge latch, which generates clamping force through mechanical engagement when closed.

[0014] Preferably, the clamping structure includes a pneumatic or electric pressure plate, which is fixed to the cover and matches the sealing ring. During closure, a small cylinder drives the pneumatic or electric pressure plate to press down, ensuring the sealing ring is evenly stressed and achieving a seal.

[0015] Compared with existing technologies, the advantages of this invention are: it achieves efficient and accurate measurement of gas sensor response time; the system structure is simple, reducing manual intervention; it is easy to operate and supports one-click testing; it has high detection efficiency; it is highly versatile and applicable to various gas sensors (such as laser, electrochemical, and optical types), which can significantly improve industrial calibration and R&D efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a flowchart illustrating the process of this utility model.

[0019] In the diagram, 1 is the sealing circulation device, 2 is the isolation sealing device, 3 is the gas distribution device, 4 is the gas concentration monitoring device, and 5 is the control unit. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] like Figure 1As shown, this utility model provides a gas sensor response time measurement system, which consists of the following key components: a closed-loop circulation device 1 serves as the test chamber to ensure a stable gas environment; an isolation and sealing device 2 is used to fix and isolate the sensor, preventing gas from prematurely entering the gas sensor under test; a gas distribution device 3 injects the target gas into the closed-loop circulation device 1 through the inlet; a gas concentration monitoring device 4 monitors the gas concentration at the outlet of the closed-loop circulation device 1 in real time; and a control unit 5 is connected to the gas distribution device, the isolation and sealing device 2, and the gas concentration monitoring device 4 to coordinate the entire process. During operation, the control unit 5 first closes the isolation and sealing device 1, putting the sensor under test in a sealed state, while the gas distribution device 3 injects gas into the closed-loop circulation device 1 through the inlet. The gas concentration monitoring device feeds back the monitoring data to the control unit 5. When the concentration reaches the preset target concentration value, the control unit 5 instantly opens the isolation and sealing device 2, exposing the gas sensor under test and starting a timer. The timer continues until the gas sensor output value reaches the target response value (e.g., 90% of the preset target concentration value), at which point the timer stops and the response time value is output and displayed on the screen. The preset target concentration value is the target gas concentration value that needs to be prepared in the closed circulation device 1. Both the preset target concentration value and the target response value can be set by the control unit in combination with the sensor's usage scenario or national standard requirements.

[0022] like Figure 1 The system composition and the connection diagrams of each component are shown, such as the circulation path of the closed circulation device, the layout of the isolation sealing device, and the interface layout of the control unit.

[0023] The closed-loop circulation device 1 includes a cavity with an air inlet and an air outlet. Baffles / grates are installed at both the air inlet and outlet positions within the cavity to rectify the airflow entering and exiting the cavity, thereby eliminating the influence of airflow on response time. The cavity is made of acrylic / glass material. Both the air inlet and outlet are connected to air pipes via quick-release connectors. All gaps in the cavity are filled with rubber gaskets to ensure a tight seal.

[0024] The isolation and sealing device 2 is centrally located within the closed-loop device 1 and is used to fix and isolate the gas sensor to be tested. The isolation and sealing device 2 is a small chamber with a controllable switch. The small chamber includes a chamber body and a cover body. The chamber body and cover body are sealed together by a sealing ring to achieve an airtight seal. The controllable switch is connected to the control unit through an electromagnetic relay. The electromagnetic relay / mechanical structure drives the rapid opening and closing, ensuring that the sensor can be fixed in a closed environment and can be exposed instantaneously after the target concentration gas stabilizes, thereby realizing standardized response time testing.

[0025] When the isolation sealing device 2 is closed, a clamping force is applied through the clamping structure to make the sealing ring fit tightly against the cabin body, thereby improving the sealing effect of the sealing ring. Specifically, the following methods can be used to achieve compression: For example, a ring-shaped compression spring or several leaf springs can be installed at the junction of the cover and the cabin of the isolation sealing device 2, i.e., on the sealing ring. When the cover is closed, the spring is compressed and generates a rebound force, so that the sealing ring is tightly combined with the cabin, thereby achieving a reliable seal; or permanent magnets / electromagnets can be arranged at the edge of the cabin, and matching iron blocks can be provided on the cover. When closed, the cover is pressed against the cabin by magnetic or electromagnetic force. The electromagnet is connected to the control unit, and the control unit 5 controls the electromagnet to achieve synchronous opening and closing; a mechanical lock can also be set between the cover and the cabin. The mechanical lock is a cam lock or a wedge lock, which is fixed on the cover and the cabin respectively, and a compression force is generated by mechanical engagement; in a further embodiment, the compression structure can also be a pneumatic pressure plate or an electric pressure plate. The pneumatic pressure plate is connected to the control unit through a small cylinder, and the electric pressure plate is connected to the control unit through a motor. When closed, the small cylinder drives the pneumatic pressure plate or the motor drives the electric pressure plate to press down, so that the sealing ring is subjected to uniform force. By combining any one or more of the above methods, a stable and reliable compression seal can be achieved when the isolation sealing device 2 is closed, thereby ensuring airtightness during the test process.

[0026] The gas mixing device 3 is connected to the air inlet on the cavity via a pipeline, and is used to inject the target concentration of gas into the closed circulation device 1. The gas mixing device 3 is a high-precision automatic gas mixing instrument of model GW-5000.

[0027] Gas concentration monitoring device 4 is connected to the outlet of the cavity to monitor the gas concentration in the closed-loop device 1 in real time. Both the inlet and outlet are normally open, and gas circulation within the closed-loop device 1 is achieved through the gas distribution device 3 and the gas concentration monitoring device 4. The gas enters the closed-loop device 1 after being proportionally controlled and uniformly mixed by the gas distribution device 3, thus ensuring a uniform gas concentration within the closed-loop device 1. Taking methane as an example, the gas concentration monitoring device 4 can be, but is not limited to, a Siemens ULTRAMAT 23 infrared analyzer.

[0028] The control unit 5 is electrically connected to the isolation sealing device 2, the gas mixing device 3, and the gas concentration monitoring device 4, respectively. It controls the opening and closing actions and processes data, and can be programmed to adjust the specific test process. The test process can be adjusted in the control unit 5 according to different standard requirements or applicable scenarios, such as modifying the sensor range, adjusting the gas mixing concentration, and setting the sensor response concentration. The control unit 5 is a controller developed based on an STM32 microcontroller, containing a timer, memory, and comparator. The memory stores preset target concentration values ​​and target response values, which are input or adjusted through the control unit. The gas sensor under test is connected to the control unit 5, and the control unit 5 reads the concentration value of the gas sensor under test in real time, without manual processing.

[0029] Control unit 5 simultaneously performs three operations: controlling gas distribution device 3 to adjust the gas to the target concentration; triggering the opening of isolation sealing device 2 and starting a timer when the concentration reaches the preset target value; and stopping the timer and outputting the response time based on the output value of the gas sensor to be measured. Control unit 5 is configured to: control the opening and closing of isolation sealing device 2; acquire real-time gas concentration data within the chamber and monitor the response value of the gas sensor to be measured; open isolation sealing device 2 and start a timer when the concentration reaches the preset target concentration; and stop the timer when the output value of the gas sensor to be measured reaches the target response value.

[0030] The measurement system of this utility model includes the following steps: sealing the gas sensor to be measured in a closed environment using a closed circulation device 1; injecting the target gas into the closed circulation device 1; monitoring the gas concentration using a gas concentration monitoring device 4 until the concentration reaches the predicted target value; opening the isolation sealing device 2 to momentarily expose the gas sensor to be measured and timing; and stopping timing when the value displayed by the gas sensor to be measured reaches the target value.

[0031] like Figure 2 The diagram illustrates a specific implementation of the measurement system of this invention. Taking a laser methane sensor with a measurement range of 0-100% LEL (the lowest volume concentration percentage at which an explosion occurs) as an example, according to the national standard GB15322.1-2019 for combustible gas detectors, the specific steps are as follows: (1) System preparation: Install the gas sensor to be tested in the isolation sealing device 2. Introduce 60% LEL methane gas into the cavity of the closed circulation device 1 through the gas distribution device 3 at a flow rate of 500 ml / min. When the gas concentration reading monitored by the gas concentration monitoring device 4 reaches 60% LEL, maintain it stably for 60 seconds to meet the national standard requirements. At this time, the isolation sealing device is in the open state. After 60 seconds, record the reading of the gas sensor to be tested as the reference value. Finally, vent the gas in the closed circulation device 1. After the gas concentration monitoring device displays the target gas concentration as zero, power on the gas sensor to be tested and run it for 5 minutes (as required by the national standard). The above is the standard response time test procedure according to GB-15322.

[0032] (2) Test Start-up: After completing the system preparation, the control unit 5 closes the isolation sealing device 2, and the isolation sealing device 2 is airtightly sealed by the sealing ring. Electromagnetic / mechanical drive enables rapid opening and closing. At the same time, in the closed state, the isolation sealing device applies a certain clamping force through the clamping structure to ensure the sealing effect. The gas distribution device 3 injects gas into the cavity through the gas inlet at a flow rate of 500 ml / min. The control unit 5 collects the concentration data monitored by the gas concentration monitoring device 4 in real time. When the concentration monitored by the gas concentration monitoring device 4 reaches 60% LEL, the control unit 5 instantly opens the isolation sealing device 2.

[0033] (3) Timing and data acquisition: When the isolation sealing device 2 is opened, the control unit 5 starts timing synchronously through the timer. The control unit 5 collects the response value of the gas sensor to be tested in real time. When the value reaches 90% of the reference value, the timing stops, and the required accurate response time data is achieved.

[0034] (4) Output results: The time taken to stop the output is the accurate response time of the sensor measured according to the national standard requirements.

[0035] The specific implementation steps and numerical recording requirements can be set according to specific standards.

[0036] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A gas sensor response time measurement system, characterized in that, It includes a closed circulation device (1), which is equipped with an isolation and sealing device (2) for accommodating the gas sensor to be tested. The closed circulation device (1) is connected to the gas distribution device (3) and the gas concentration monitoring device (4) respectively. The gas sensor to be tested, the isolation and sealing device (2), the gas distribution device (3) and the gas concentration monitoring device (4) are all connected to the control unit (5).

2. The gas sensor response time measurement system according to claim 1, characterized in that, The closed circulation device (1) includes a cavity with an air inlet and an air outlet. The air inlet is connected to the gas distribution device (3), and the air outlet is connected to the gas concentration monitoring device (4).

3. The gas sensor response time measurement system according to claim 2, characterized in that, The cavity at the location of the air inlet and air outlet is equipped with baffles or grilles.

4. The gas sensor response time measurement system according to claim 2 or 3, characterized in that, Both the air inlet and outlet are connected to the air pipe via quick-release connectors, and the air pipe is connected to the gas distribution device (3) and the gas concentration monitoring device (4) respectively.

5. The gas sensor response time measurement system according to claim 4, characterized in that, The isolation and sealing device (2) is a chamber with a controllable switch, and a gas sensor to be tested is installed inside the chamber; the controllable switch is connected to the control unit (5); the chamber is connected to the cover through a sealing ring.

6. The gas sensor response time measurement system according to claim 5, characterized in that, The isolation sealing device (2) applies a clamping force through the clamping structure in the closed state, so that the sealing ring fits tightly against the cabin.

7. The gas sensor response time measurement system according to claim 6, characterized in that, The clamping structure includes a ring-shaped clamping spring or several leaf springs disposed at the junction of the cover and the cabin.

8. The gas sensor response time measurement system according to claim 6, characterized in that, The clamping structure includes a permanent magnet or electromagnet located at the edge of the cabin, and an iron block adapted to the permanent magnet or electromagnet is provided on the cover; the permanent magnet or electromagnet is electrically connected to the control unit (5).

9. The gas sensor response time measurement system according to claim 6, characterized in that, The clamping structure includes a mechanical latch disposed between the cover and the cabin, wherein the mechanical latch is a cam latch or a wedge latch.

10. The gas sensor response time measurement system according to claim 6, characterized in that, The clamping structure includes a pneumatic or electric clamping plate, which is fixed to the cover and matches the sealing ring.

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