A soil layer greenhouse gas collection device and a collection method
By employing a layered mechanism and inner and outer cylinder design, the problem of inaccurate sampling depth adjustment and monitoring in humid environments in existing soil greenhouse gas collection devices has been solved, achieving flexible adjustment and high-precision greenhouse gas collection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HANGZHOU METEOROLOGICAL BUREAU
- Filing Date
- 2023-02-14
- Publication Date
- 2026-06-19
AI Technical Summary
Existing soil greenhouse gas sampling devices cannot flexibly adjust the sampling depth and are easily affected by humid environments, resulting in inaccurate monitoring results.
The depth of the sampling support is adjusted by a layered mechanism and a drive mechanism. Combined with the inner and outer cylinder structure and a waterproof and breathable membrane, the inner cylinder drives the sealing plate to achieve time-series sampling. An opening and closing mechanism is used to ensure the accuracy of gas sampling.
It enables flexible adjustment of sampling depth under different terrain conditions, prevents water vapor from affecting the sampling, and ensures the accuracy of gas collection and the precision of multiple samplings.
Smart Images
Figure CN117250053B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of greenhouse gas detection technology, specifically to a soil greenhouse gas collection device and collection method. Background Technology
[0002] Soil is the largest terrestrial carbon pool on Earth, accounting for about two-thirds of the global total. Studying soil respiration is of great significance for understanding the underground carbon flux and carbon distribution patterns in terrestrial ecosystems. Existing soil greenhouse gas sampling devices use fixed sampling tubes, which cannot adjust their sampling depth according to different terrain environments, thus limiting the use of these devices. At the same time, since long-term continuous observation of greenhouse gas emissions from soil layers is sometimes required, the monitoring methods using sensors are not suitable for humid or high-humidity environments, which can easily affect the monitoring results. Direct sampling methods can create negative pressure in the sampling tube, disturbing the airflow and making it impossible to accurately obtain the gas concentration at the current time point, thus failing to achieve effective monitoring of soil respiration. Summary of the Invention
[0003] Technical Objective: To address the shortcomings of existing soil greenhouse gas collection devices, which have fixed collection tube positions, cannot flexibly adjust sampling depth according to environmental changes, and whose methods of direct monitoring with sensors and sampling are limited and easily affected by the environment, thus failing to effectively monitor soil respiration, this invention discloses a soil greenhouse gas collection device and collection method that can flexibly adjust the sampling depth range according to environmental needs and effectively monitor soil respiration.
[0004] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:
[0005] A soil greenhouse gas collection device includes a collection support frame. The collection support frame is provided with a layering mechanism along its length, which divides the collection support frame into several collection zones along its length. Each collection zone is provided with a collection cylinder for collecting gas at a corresponding depth. The collection cylinder is fixed on the layering mechanism. The layering mechanism includes an adjusting plate and a sealing gas ring embedded in the outer periphery of the adjusting plate. The adjusting plate is limited by an adjusting rod on the collection support frame. The adjusting plate and the adjusting rod are screwed together. A drive mechanism is provided below the collection support frame for rotating the adjusting rod to adjust the layering depth of the collection zone.
[0006] Preferably, the driving mechanism of the present invention includes a base and a power source. The acquisition bracket is installed on the base, the lower end of the adjusting rod extends into the base and is rotatably connected to the base, the power source is fixed on the base, and a driving wheel is fixed at the driving end of the power source. The teeth of the driving wheel mesh with the driving wheel fixed on the adjusting rod. The power source drives the driving wheel to rotate through the driving wheel to adjust the height of the adjusting plate.
[0007] Preferably, the collection tube of the present invention includes an outer cylinder and an inner cylinder. The outer cylinder is fixed on an adjustment plate and has vent holes for collecting gas flow on its side wall. The inner cylinder is concentrically arranged inside the outer cylinder and has a waterproof and breathable membrane on its outside.
[0008] Preferably, the inner cylinder of the present invention has sub-sampling tubes distributed on its outer periphery. The bottom of the sub-sampling tubes is fixedly connected to the outer cylinder, and the upper part is provided with an opening for air intake. The inner cylinder is rotatably disposed inside the outer cylinder. The inner cylinder is driven to rotate by a second driving mechanism disposed on the adjusting plate. A sealing plate is provided on the outer periphery of the inner cylinder for sealing the sub-sampling tubes as the inner cylinder rotates.
[0009] Preferably, the sub-sampling tubes of the present invention are evenly distributed along the outer circumference of the inner cylinder, the height of the tube openings of the sub-sampling tubes increases sequentially along the circumferential direction, and the sealing plates are arranged along the circumferential direction of the inner cylinder according to the distribution spacing of the sub-sampling tubes; the tube openings of the sub-sampling tubes are provided with arc-shaped grooves, the shape of which is a concentric arc with the axis of the inner cylinder as the center, and the lower surface of the sealing plates is provided with locking blocks for cooperating with the arc-shaped grooves.
[0010] Preferably, the card block of the present invention includes guide portions at both ends and a sealing and pressing portion between the guide portions. The guide portions adopt an elliptical spindle-shaped structure, and there is a smooth transition between the sealing and pressing portion and the guide portions. An elastic and stretchable material is wrapped around the outside of the sealing and pressing portion.
[0011] Preferably, the sub-sampling tube, inner tube, and outer tube of the present invention are all connected to an external sampling device through separate air tubes. The air tubes are connected to the bottom of the outer tube, and their ends pass through the outer tube and are connected to the corresponding tubes.
[0012] Preferably, the present invention has an opening and closing mechanism at the bottom of the sub-sampling cylinder for connecting with the air tube when the sub-sampling cylinder is closed by the sealing plate. The opening and closing mechanism includes a sealing plate and a T-shaped connecting seat. The sealing plate is located inside the sub-sampling cylinder. The upper end of the T-shaped connecting seat passes through the sub-sampling cylinder and connects to the sealing plate. A spring is sleeved on the T-shaped connecting seat to keep the sealing plate pressed tightly at the bottom of the sub-sampling cylinder for sealing. The T-shaped connecting seat has a connecting hole with an open bottom end. The air tube communicates with the connecting hole. A vent hole is opened on the side wall of the upper part of the connecting hole. When the sub-sampling cylinder is blocked and pressed down by the sealing plate, the air tube lifts up the T-shaped connecting seat, realizing the connection between the air tube and the sub-sampling cylinder.
[0013] The present invention also provides a method for collecting greenhouse gases based on the above-mentioned soil layer greenhouse gas collection device, comprising the following steps:
[0014] S01. Select a collection point based on the greenhouse gas collection requirements, and set up a collection room at the collection point that can accommodate the greenhouse gas collection device, and place the collection device there.
[0015] S02. Start the drive mechanism. The power source drives the adjusting rod to rotate. The adjusting plate, which is screwed to the adjusting rod, moves along the axis of the adjusting rod to change the height of the fixed collection tube.
[0016] S03. After the collection tube is adjusted to the correct position, inflate the sealing ring around the outer periphery of the adjustment plate. The sealing ring expands, dividing the collection chamber vertically into separate collection areas.
[0017] S04. Greenhouse gases escaping from the soil layer enter through the vents in the outer cylinder of the collection tube, thus collecting the greenhouse gases. Gas samples are then extracted from the collection tube through a gas pipe connected to the collection tube.
[0018] Preferably, in step S04 of the present invention, when it is necessary to detect the gas emission rate, the second driving mechanism drives the inner cylinder to rotate, the sealing plate seals the sub-sampling tubes in time sequence, seals the gas at the current time point in the sub-sampling tube, the opening and closing mechanism located below the sub-sampling tube opens, and the emission rate is determined by detecting the gas concentration collected in the sub-sampling tube.
[0019] Beneficial effects: The soil greenhouse gas collection device and method provided by this invention have the following beneficial effects:
[0020] 1. The adjusting plate and adjusting rod of the present invention are screwed together. The adjusting rod is driven to rotate by the driving mechanism to realize the height adjustment of the adjusting plate, so that the device can meet the greenhouse gas sampling requirements in different environments and improve the adaptability of the device.
[0021] 2. The collection tube of the present invention is divided into an outer tube and an inner tube, and a waterproof and breathable membrane is provided on the outside of the inner tube. When the external environment is relatively humid or it is raining, it can prevent external water vapor from entering the inner tube, and the device can still collect greenhouse gases.
[0022] 3. The inner cylinder and outer cylinder of the present invention are rotatably connected. Several sub-sampling cylinders are set outside the inner cylinder. By rotating the inner cylinder, the sealing plate is driven to seal the sub-sampling cylinders. According to the sampling and detection requirements, the sub-sampling cylinders can be sealed in sequence according to time, so as to realize the sealing and detection of gas concentration at different time points. Furthermore, when sampling the sealed sub-sampling cylinders, it can avoid disturbing the gas inside the outer cylinder and avoid affecting the external gas sampling environment due to gas extraction.
[0023] 4. An opening and closing mechanism is provided below the sub-sampling tube of the present invention. When the opening of the sub-sampling tube is sealed by the sealing plate, the sub-sampling tube is pressed down, the opening and closing mechanism is pressed down, and the T-shaped connecting seat is lifted up, so as to realize the connection between the gas tube and the sub-sampling tube. According to the needs, the greenhouse gas concentration at different time points can be collected to detect the soil respiration rate.
[0024] 5. The opening and closing mechanism of the present invention realizes the connection and closing between the sub-sampling tube and the air tube through the sealing plate and the T-shaped connecting seat. It can cooperate with the locking block above the sub-sampling tube to realize the connection between its bottom and the air tube while the sub-sampling tube is blocked. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.
[0026] Figure 1 This is a structural diagram of the present invention;
[0027] Figure 2 This is a diagram of the internal structure of the collection tube of the present invention;
[0028] Figure 3 This is a cross-sectional view of the card block of the present invention;
[0029] Figure 4 This is a diagram of the internal structure of the sampling tube of the present invention;
[0030] Among them, 1-collection tube, 2-adjusting plate, 3-sealing air ring, 4-adjusting rod, 5-base, 6-power source, 7-drive wheel, 8-drive wheel, 9-outer cylinder, 10-inner cylinder, 11-air hole, 12-sub-sampling tube, 13-blocking plate, 14-arc groove, 15-blocking block, 16-guide part, 17-sealing and pressing part, 18-sealing plate, 19-T-type connecting seat, 20-spring, 21-connecting hole, 22-vent hole, 23-second drive mechanism. Detailed Implementation
[0031] The present invention will now be described more clearly and completely by way of a preferred embodiment in conjunction with the accompanying drawings, but this does not limit the invention to the scope of the described embodiment.
[0032] like Figure 1 The image shows a soil greenhouse gas collection device disclosed in this invention, comprising a collection support frame. The collection support frame is provided with a layering mechanism along its length, which divides the collection support frame along its length into several collection zones. Each collection zone is provided with a collection cylinder 1 for collecting gas at a corresponding depth. The collection cylinder 1 is fixed on the layering mechanism. The layering mechanism includes an adjusting plate 2 and a sealing gas ring 3 embedded on the outer periphery of the adjusting plate 2. The adjusting plate 2 is limited by an adjusting rod 4 on the collection support frame. The adjusting plate 2 and the adjusting rod 4 are screwed together. A drive mechanism is provided below the collection support frame for rotating the adjusting rod 4 to adjust the layering depth of the collection zone.
[0033] In one specific embodiment, the driving mechanism of the present invention includes a base 5 and a power source 6. The acquisition bracket is installed on the base 5, the lower end of the adjusting rod 4 extends into the base 5 and is rotatably connected to the base 5, the power source 6 is fixed on the base 5, and a driving wheel 7 is fixed at the driving end of the power source 6. The teeth of the driving wheel 7 mesh with the driving wheel 8 fixed on the adjusting rod 4. The power source 6 drives the driving wheel 8 to rotate through the driving wheel 7 to adjust the height of the adjusting plate 2.
[0034] Depending on the different terrain and environment of different regions, the height of the collection area can be adjusted by starting the power source 6 to drive the drive wheel 8 on the adjustment rod 4, thereby improving the adaptability of the collection device.
[0035] In some humid areas or when there is a lot of rain, ordinary collection tubes may experience backflow of water vapor, which can affect their ability to collect greenhouse gases from the soil layer. In this invention, the collection tube 1 includes an outer tube 9 and an inner tube 10. The outer tube 9 is fixed on an adjusting plate 2, and air holes 11 for gas flow are provided on the side wall of the outer tube 9. The inner tube 10 is concentrically arranged inside the outer tube 9, and a waterproof and breathable membrane is provided on the outside of the inner tube 10. In a dry environment, both the outer tube 9 and the inner tube 10 can collect greenhouse gases normally, and the waterproof and breathable membrane will not affect the flow of gases. When the external humidity increases or there is rainfall, the outer tube 9, which is located on the outside, cannot continue to collect gases, but the inner tube 10, because it is covered with a waterproof and breathable membrane, can still collect greenhouse gases normally, thus ensuring that greenhouse gas collection from the soil layer can still be maintained in humid or rainy environments.
[0036] When conducting greenhouse gas analysis in soil layers, depending on the region, it is necessary to detect the greenhouse gas respiration rate of the soil layer to assess the carbon capacity of a certain area. Existing sampling methods mainly involve directly extracting gases from the collection area through pipelines for analysis. However, direct extraction creates local negative pressure at the end of the pipeline, affecting the normal dissipation and flow of greenhouse gases. When multiple samplings are required, it affects the subsequent sampling accuracy, resulting in low accuracy of the results. To address this, the present invention has sub-sampling cylinders 12 distributed around the outer periphery of the inner cylinder 10. The bottom of the sub-sampling cylinder 12 is fixedly connected to the outer cylinder 9, and an opening for air intake is provided at the top. The inner cylinder 10 is rotatably disposed inside the outer cylinder 9. The inner cylinder 10 is driven to rotate by a second drive mechanism 23 mounted on the adjusting plate 2. Specifically, the second drive mechanism 23 can be driven by an electric motor or a pneumatic motor. A sealing plate 13 is provided around the outer periphery of the inner cylinder 10 for sealing the sub-sampling cylinders 12 as the inner cylinder 10 rotates.
[0037] After the sub-sampling tube 12 has finished sampling, the sub-sampling tube 12 is directly sealed by the sealing plate 13, which can avoid the influence of sampling and aspiration of other areas. Specifically, the sub-sampling tubes 12 of the present invention are evenly distributed along the outer periphery of the inner cylinder 10, and the height of the tube opening of the sub-sampling tube 12 increases sequentially along the circumferential direction. The sealing plate 13 is arranged along the circumferential direction of the inner cylinder 10 according to the distribution spacing of the sub-sampling tubes 12. The tube opening of the sub-sampling tube 12 is provided with an arc-shaped groove 14. The shape of the arc-shaped groove 14 is a concentric arc with the axis of the inner cylinder 10 as the center. The lower surface of the sealing plate 13 is provided with a locking block 15 for cooperating with the arc-shaped groove 14.
[0038] The card block 15 includes guide portions 16 located at both ends and a sealing and pressing portion 17 located between the guide portions 16. The guide portions 16 adopt an elliptical spindle-shaped structure. The sealing and pressing portion 17 and the guide portions 16 are smoothly transitioned. The sealing and pressing portion 17 is covered with an elastic and stretchable material. The sub-sampling cylinder 12, the inner cylinder 10, and the outer cylinder 9 are all connected to the external sampling device through separate air tubes. The air tubes are connected to the bottom of the outer cylinder 9, and the ends pass through the outer cylinder 9 and are connected to the corresponding cylinders.
[0039] As the inner cylinder 10 rotates, the guide part 16 first enters the arc-shaped slot 14 to ensure that the locking block 15 can enter smoothly. Then, the sealing and pressing part 17 seals the sub-sampling cylinder 12. After sealing, the sub-sampling cylinder is evacuated for sampling. The present invention also provides an opening and closing mechanism at the bottom of the sub-sampling cylinder 12 for connecting with the air tube when the sub-sampling cylinder 12 is closed by the sealing plate 13. The opening and closing mechanism includes a sealing plate 18 and a T-shaped connecting seat 19. The sealing plate 18 is located inside the sub-sampling cylinder 12, and the T-shaped connecting seat 19 is located inside the sub-sampling cylinder 12. The upper end of the tube 9 passes through the sub-sampling cylinder 12 and connects to the sealing plate 18. A spring 20 is fitted onto the T-shaped connecting seat 19 to keep the sealing plate 18 pressed tightly against the bottom of the sub-sampling cylinder 12 for sealing. The T-shaped connecting seat 19 has a connecting hole 21 with an open bottom end, through which the air pipe communicates. A vent hole 22 is opened on the upper side wall of the connecting hole 21. When the sub-sampling cylinder 12 is blocked and pressed down by the sealing plate 13, the air pipe pushes up the T-shaped connecting seat 19, realizing the communication between the air pipe and the sub-sampling cylinder 12. While sealing the sub-sampling cylinder 12, the communication between the air pipe and the sub-sampling cylinder can be realized. Furthermore, when the sub-sampling cylinder 12 is collecting greenhouse gases, the air pipe and the sub-sampling cylinder remain in a closed state, maintaining the closure of the collection area.
[0040] The present invention also provides a method for collecting greenhouse gases from the soil layer using the above-mentioned greenhouse gas collection device, comprising the following steps:
[0041] S01. Select a collection point based on the greenhouse gas collection requirements, and set up a collection room at the collection point that can accommodate the greenhouse gas collection device, and place the collection device there.
[0042] S02. Start the drive mechanism. The power source drives the adjusting rod to rotate. The adjusting plate, which is screwed to the adjusting rod, moves along the axis of the adjusting rod to change the height of the fixed collection tube.
[0043] S03. After the collection tube is adjusted to the correct position, inflate the sealing ring around the outer periphery of the adjustment plate. The sealing ring expands, dividing the collection chamber vertically into separate collection areas.
[0044] S04. Greenhouse gases escaping from the soil layer enter through the vents in the outer cylinder of the collection tube, thus collecting the greenhouse gases. Gas samples are then extracted from the collection tube through a gas pipe connected to the collection tube.
[0045] When it is necessary to detect the gas emission rate, the second drive mechanism drives the inner cylinder to rotate, and the sealing plate seals the sub-sampling tubes in time sequence, sealing the gas at the current time point inside the sub-sampling tube. The opening and closing mechanism located below the sub-sampling tube opens, and the emission rate is determined by detecting the gas concentration collected in the sub-sampling tube.
[0046] The collection device of this invention can meet the gas collection needs under different terrain environments. In conjunction with temperature and humidity sensors and data acquisition and analysis instruments, it can realize the analysis of greenhouse gas emission at different depths of the soil layer. It can continuously monitor the respiration state of the soil layer while detecting the emission rate of greenhouse gases.
[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A soil layer greenhouse gas collection apparatus, characterized by, The system includes a collection bracket, which has a layering mechanism along its length to divide the collection bracket into several collection zones. Each collection zone has a collection cylinder (1) for collecting gas at a corresponding depth. The collection cylinder (1) is fixed on the layering mechanism. The layering mechanism includes an adjustment plate (2) and a sealing gas ring (3) embedded on the outer periphery of the adjustment plate (2). The adjustment plate (2) is limited by an adjustment rod (4) on the collection bracket. The adjustment plate (2) and the adjustment rod (4) are screwed together. A drive mechanism is provided below the collection bracket to drive the adjustment rod (4) to rotate and adjust the layering depth of the collection zone. The drive mechanism includes a base (5) and a power source (6). The collection bracket is installed on the base (5). The lower end of the adjusting rod (4) extends into the base (5) and is rotatably connected to the base (5). The power source (6) is fixed on the base (5). A drive wheel (7) is fixed at the drive end of the power source (6). The teeth of the drive wheel (7) mesh with the drive wheel (8) fixed on the adjusting rod (4). The power source (6) drives the drive wheel (8) to rotate through the drive wheel (7) to adjust the height of the adjusting plate (2). The collection tube (1) includes an outer tube (9) and an inner tube (10). The outer tube (9) is fixed on the adjusting plate (2). The side wall of the outer tube (9) is provided with a vent (11) for collecting gas flow. The inner tube (10) is concentrically arranged inside the outer tube (9). A waterproof and breathable membrane is provided on the outside of the inner tube (10). The inner cylinder (10) has sub-sampling tubes (12) distributed around its outer periphery. The bottom of the sub-sampling tube (12) is fixedly connected to the outer cylinder (9), and an opening for air intake is provided at the top. The inner cylinder (10) is rotatably disposed inside the outer cylinder (9). The inner cylinder (10) is driven to rotate by the second drive mechanism (23) provided on the adjustment plate (2). A sealing plate (13) is provided on the outer periphery of the inner cylinder (10) for sealing the sub-sampling tubes (12) as the inner cylinder (10) rotates. The sub-sampling tube (12), inner tube (10), and outer tube (9) are all connected to the external sampling device through separate air tubes. When the sub-sampling tube (12) is blocked and pressed down by the sealing plate (13), the air tube is connected to the sub-sampling tube (12).
2. The soil layer greenhouse gas collection apparatus of claim 1, wherein, The sub-sampling tubes (12) are evenly distributed along the outer periphery of the inner cylinder (10). The height of the tube opening of the sub-sampling tubes (12) increases sequentially along the circumferential direction. The sealing plates (13) are arranged along the circumferential direction of the inner cylinder (10) according to the distribution spacing of the sub-sampling tubes (12). The tube opening of the sub-sampling tubes (12) is provided with an arc-shaped groove (14). The arc-shaped groove (14) is a concentric arc with the axis of the inner cylinder (10) as the center. The lower surface of the sealing plate (13) is provided with a locking block (15) for cooperating with the arc-shaped groove (14).
3. The soil layer greenhouse gas collection apparatus of claim 2, wherein, The card block (15) includes guide portions (16) located at both ends and a sealing and pressing portion (17) located between the guide portions (16). The guide portions (16) adopt an elliptical spindle-shaped structure. The sealing and pressing portion (17) and the guide portions (16) are smoothly transitioned. The sealing and pressing portion (17) is covered with an elastic and stretchable material.
4. The soil layer greenhouse gas collection apparatus of claim 3, wherein, The trachea is connected to the bottom of the outer cylinder (9), and its end passes through the outer cylinder (9) and is connected to the corresponding cylinder.
5. The soil layer greenhouse gas collection apparatus of claim 4, wherein, The bottom of the sub-sampling tube (12) is provided with an opening and closing mechanism for connecting with the air tube when the sub-sampling tube (12) is closed by the sealing plate (13). The opening and closing mechanism includes a sealing plate (18) and a T-shaped connecting seat (19). The sealing plate (18) is located inside the sub-sampling tube (12). The upper end of the T-shaped connecting seat (19) passes through the sub-sampling tube (12) and is connected to the sealing plate (18). A spring (20) is sleeved on the T-shaped connecting seat (19) to keep the sealing plate (18) pressed against the bottom of the sub-sampling tube (12) for sealing. The T-shaped connecting seat (19) is provided with a connecting hole (21) with an open bottom end. The air tube is connected to the connecting hole (21). A ventilation hole (22) is opened on the side wall of the upper part of the connecting hole (21).
6. A method for capturing greenhouse gases from a soil layer, using the soil layer greenhouse gas capture device according to any one of claims 1-5, characterized in that, Including the following steps: S01. Select a collection point based on the greenhouse gas collection requirements, and set up a collection room at the collection point that can accommodate the greenhouse gas collection device, and place the collection device there. S02. Start the drive mechanism. The power source drives the adjusting rod to rotate. The adjusting plate, which is screwed to the adjusting rod, moves along the axis of the adjusting rod to change the height of the fixed collection tube. S03. After the collection tube is adjusted to the correct position, inflate the sealing ring around the outer periphery of the adjustment plate. The sealing ring expands, dividing the collection chamber vertically into separate collection areas. S04. Greenhouse gases escaping from the soil layer enter through the vents in the outer cylinder of the collection tube, thus collecting the greenhouse gases. Gas samples are then extracted from the collection tube through a gas pipe connected to the collection tube.
7. The method of claim 6, wherein the soil layer is a soil layer of a soil surface. In step S04, when it is necessary to detect the gas emission rate, the second drive mechanism drives the inner cylinder to rotate, and the sealing plate seals the sub-sampling tubes in time sequence, sealing the gas at the current time point inside the sub-sampling tube. The opening and closing mechanism located below the sub-sampling tube opens, and the emission rate is determined by detecting the gas concentration collected inside the sub-sampling tube.