A device for in-situ measurement of ammonia volatilization from plant canopy

Abstract

This utility model relates to the field of ammonia volatilization measurement technology in plant canopies, and discloses an in-situ ammonia volatilization measurement device for plant canopies, including a pump-suction portable ammonia detector, a connecting tube, and a gas collection chamber. The pump-suction portable ammonia detector has an inlet end for measuring the concentration of ammonia. The gas collection chamber is a closed structure used to cover the plant to be measured and has an outlet end. The connecting tube connects one end to the inlet end of the pump-suction portable ammonia detector and the other end to the outlet end of the gas collection chamber. This solution can acquire and display measurement data in real time, and can capture the instantaneous dynamic changes in ammonia volatilization in plant canopies. The entire measurement process does not require the preparation, placement, and recovery of the adsorbent carrier, nor does it require complex extraction and analysis operations, which greatly simplifies the measurement steps, reduces the risk of human error introduced by multiple operations, and improves the accuracy and efficiency of the measurement.

Description

Technical Field

[0001] This utility model relates to the field of plant canopy ammonia volatilization measurement technology, and more specifically, to an in-situ measurement device for plant canopy ammonia volatilization. Background Technology

[0002] Farmland ecosystems are significant sources of atmospheric ammonia (NH3) emissions. Ammonia volatilization is not only a major pathway for nitrogen loss from fertilizers but also triggers a series of environmental problems, such as air pollution, water eutrophication, and soil acidification. The plant canopy plays a dual role in the biogeochemical cycle of ammonia; it can absorb atmospheric ammonia as a nutrient source but may also release ammonia into the atmosphere under specific conditions (such as after fertilization). Therefore, accurately quantifying the ammonia volatilization flux from the plant canopy is crucial for scientifically evaluating nitrogen fertilizer utilization, reducing environmental pollution, and guiding green agricultural production.

[0003] Currently, the main methods for measuring ammonia volatilization in farmland include the micrometeorological method and the closed-cell extraction method (or closed-chamber method). The micrometeorological method is suitable for large-scale regional flux calculation, but it has extremely stringent requirements on the homogeneity of the underlying surface, meteorological conditions, and the measurement area, and the equipment is expensive. It also cannot distinguish the contributions of the canopy and the soil.

[0004] A more widely used method is the closed-loop vacuum method. For example, patent application CN102279179A discloses a "device and monitoring method for in-situ field study of ammonia exchange in crop canopy". This method uses an airtight culture hood that covers both the soil and the plant canopy. Adsorption carriers (such as sponges) soaked in dilute acid are placed at the top and bottom of the hood, respectively. A vacuum pump is used to remove air, allowing ammonia to be absorbed by the acidic carriers. After the measurement, the carriers need to be brought back to the laboratory for chemical analysis using equipment such as an ultraviolet spectrophotometer. The canopy ammonia exchange capacity is indirectly estimated by calculating the difference in ammonia adsorption capacity between the two groups of carriers.

[0005] While this method enables in-situ monitoring in the field, it still has significant limitations: 1. Inability to measure in real time: This method is a cumulative and lagging measurement method, requiring multiple offline analysis steps such as sampling, extraction, and testing. The operation is cumbersome and time-consuming, making it impossible to quickly obtain real-time data and capture the instantaneous dynamic changes in ammonia volatilization. 2. Complex operation and potential for errors: The preparation, placement, retrieval, extraction, and chemical analysis of the acidic support involve many steps. Improper operation at any stage can introduce human error, affecting the accuracy of the results. Utility Model Content

[0006] The present invention aims to overcome at least one of the defects of the prior art and provide an in-situ measuring device for ammonia volatilization in plant canopies, which solves the technical problems of existing closed-loop extraction methods being unable to provide real-time readings, cumbersome operation, and poor device portability.

[0007] The technical solution adopted by this utility model is an in-situ measuring device for ammonia volatilization in plant canopies, including a pump-suction portable ammonia detector, a connecting pipe, and a gas collection chamber; the pump-suction portable ammonia detector has an inlet end for measuring the concentration of ammonia; the gas collection chamber is a closed structure used to cover the plant to be measured and has an outlet end; the connecting pipe is connected at one end to the inlet end of the pump-suction portable ammonia detector and at the other end to the outlet end of the gas collection chamber.

[0008] This solution uses a pump-driven portable ammonia detector as its core component, enabling direct and continuous reading of ammonia concentration within a sealed chamber. It completely eliminates the lag steps of carrier adsorption and laboratory chemical analysis required in existing technologies, allowing for real-time acquisition and display of measurement data. It can capture the instantaneous dynamic changes in ammonia volatilization from plant canopies. The entire measurement process eliminates the need for preparing, placing, and recovering the adsorption carrier, as well as complex extraction and analysis operations, greatly simplifying the measurement steps, reducing the risk of human error introduced by multiple steps, and improving measurement accuracy and work efficiency.

[0009] Furthermore, the gas collection chamber includes a cylindrical body and a top cover. The top cover is fastened to the top of the cylindrical body, and a gas nozzle is provided at the top of the top cover for connecting the other end of the connecting pipe.

[0010] Furthermore, the cylindrical body is formed by rolling up a flexible plate, and magnets that attract each other are correspondingly arranged on opposite sides of the flexible plate.

[0011] Furthermore, the flexible plate is made of polyvinyl chloride, polyethylene, or thermoplastic polyurethane elastomer.

[0012] Furthermore, the gas collection chamber includes a support frame and a collection film sleeve fitted on the support frame. The collection film sleeve is provided with a second air nozzle for connecting the other end of the connecting pipe.

[0013] Furthermore, the support frame includes a top frame, a bottom frame, and longitudinal telescopic rods connecting the top frame and the bottom frame, wherein there are at least two longitudinal telescopic rods.

[0014] Furthermore, the top frame and / or bottom frame are formed by connecting horizontal telescopic rods and transverse telescopic rods end to end with connecting angle irons.

[0015] Furthermore, the connecting angle iron has three mutually perpendicular connecting surfaces, each with a through hole; the ends of the longitudinal telescopic rod, the horizontal telescopic rod, and the transverse telescopic rod are all provided with external thread sections; the external thread sections pass through the corresponding through holes and are locked with nuts, so that the longitudinal telescopic rod, the horizontal telescopic rod, and the transverse telescopic rod are respectively fixedly connected to the connecting angle iron.

[0016] Furthermore, the connecting angle iron has three mutually perpendicular connecting surfaces, each with a latch; the ends of the longitudinal telescopic rod, the horizontal telescopic rod, and the transverse telescopic rod are all provided with snap-fit ​​posts with annular grooves; the snap-fit ​​posts engage with the corresponding latches to fix the longitudinal telescopic rod, the horizontal telescopic rod, and the transverse telescopic rod to the connecting angle iron respectively.

[0017] Furthermore, the material of the airtight film sleeve is polyethylene, polyvinyl chloride, or ethylene-vinyl acetate copolymer.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model uses a pump-type portable ammonia detector as the core detection component, which can directly and continuously read the ammonia concentration in the closed gas chamber, completely eliminating the lagging links such as carrier adsorption and laboratory chemical analysis required in the prior art. It can acquire and display measurement data in real time and can capture the instantaneous dynamic changes of ammonia volatilization in the plant canopy.

[0019] The entire measurement process does not require the preparation, placement, and recovery of the adsorbent carrier, nor does it require complex extraction and testing operations. This greatly simplifies the measurement steps, reduces the risk of human error introduced by multiple steps, and improves the accuracy and efficiency of the measurement.

[0020] The entire device has a simple structure, small size, and light weight, making it easy to carry to the field for in-situ measurements. The gas collection chamber can adopt a flexible or foldable structure (such as the combination of a flexible plate or support frame with a film sleeve in the embodiment) according to actual needs. This not only facilitates storage and transportation but also allows for flexible coverage of plant canopies of different sizes and heights, significantly improving the practicality and applicability of the device. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this utility model.

[0022] Figure 2 This is a schematic diagram of the gas collection chamber in Embodiment 1 of this utility model.

[0023] Figure 3 This is a schematic diagram of the structure of the flexible plate after it is unfolded in Embodiment 1 of this utility model.

[0024] Figure 4 This is a schematic diagram of the gas collection chamber in Embodiment 2 of this utility model.

[0025] Figure 5 This is a schematic diagram of the support frame in Embodiment 2 of this utility model.

[0026] Figure 6 This utility model Figure 5Enlarged view of the connection points between the horizontal telescopic bar, the transverse telescopic bar, the longitudinal telescopic bar and the connecting angle iron.

[0027] Figure 7 This is a schematic diagram showing the horizontal telescopic rod, the transverse telescopic rod, the longitudinal telescopic rod, and the connecting angle iron respectively snapped together in Embodiment 2 of this utility model.

[0028] In the diagram: 1. Pump-type portable ammonia detector; 2. Connecting pipe; 3. Gas collection chamber; 4. Top cover; 5. Flexible plate; 6. Nozzle 1; 7. Magnet; 8. Collection film sleeve; 9. Nozzle 2; 10. Connecting angle iron; 11. Longitudinal telescopic rod; 12. Horizontal telescopic rod; 13. Lateral telescopic rod. Detailed Implementation

[0029] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0030] Example 1 like Figure 1-3 As shown in the figure, this embodiment discloses an in-situ measuring device for ammonia volatilization in plant canopies, including a pump-type portable ammonia detector 1 and a gas collection chamber 3. The gas collection chamber 3 is connected to the pump-type portable ammonia detector 1 through a connecting pipe 2.

[0031] The portable ammonia detector (PAD) is an existing device, and its specific structure and working principle are well known to those skilled in the art, and will not be described in detail here. In this solution, a detector with a measurement range of 0–10 ppm and a measurement accuracy of 0.001 ppm is preferred. This range and accuracy configuration can meet the measurement needs of most plant canopy ammonia volatilization concentrations. In practical applications, other detectors with higher ranges or higher accuracy can be selected according to the specific measurement object and environment.

[0032] The connecting pipe 2 is preferably a flexible hose, such as a rubber hose. Using a flexible hose makes it easier to adjust the position of the pump-suction portable ammonia detector 1, making it more flexible to use.

[0033] The air collection chamber 3 includes a flexible plate 5 and a top cover 4. Several magnets 7 are vertically attached to both sides of the flexible plate 5. The magnets 7 can be magnets with strong attraction force. When the flexible plate 5 is rolled into a cylindrical shape, the magnets 7 on both sides are magnetically attracted to each other to maintain the cylindrical shape of the flexible plate 5. The top cover 4 is fastened to the top of the rolled-up flexible plate 5 (the sizes match to form a tight fit and prevent air leakage). An air nozzle 6 is installed on the top cover 4 for connecting the connecting pipe 2.

[0034] When it is necessary to measure the ammonia volatilization of a plant canopy, the flexible plate 5 is rolled into a tube and covered to cover the plant to be measured. The magnets 7 on both sides of the flexible plate 5 magnetically attract the flexible plate 5 to maintain its cylindrical shape (the two ends of the flexible plate 5 are in contact to form a seal). The top cover 4 is fastened to the top of the cylindrical flexible plate 5, and the air nozzle 6 on the top cover 4 is connected to the pump-suction portable ammonia detector 1. That is, the ammonia volatilization of the specific plant can be measured by the pump-suction portable ammonia detector 1. When it is necessary to remove it, the connecting tube 2 is disassembled, the top cover 4 is removed, and the magnets 7 are pulled open, so that the flexible plate 5 returns to a plate. It occupies little space and is easy to move and transport.

[0035] Example 2 like Figure 4-7 As shown, the difference between this embodiment and the first embodiment is that the gas collection chamber 3 in this embodiment includes a support frame and a collection film sleeve 8 fitted on the support frame.

[0036] The support frame includes a top frame and a bottom frame, which are connected by four longitudinal telescopic rods 11 (preferably four, but more than four can be set, at least two to ensure stable support). The top frame and bottom frame can be circular or rectangular, and the dimensions between the top frame and bottom frame can be adjusted by the four longitudinal telescopic rods 11.

[0037] When the top and bottom frames are rectangular, the top frame (the bottom frame has the same structure as the top frame) can be formed by connecting two horizontal telescopic rods 12 and two transverse telescopic rods 13. The horizontal telescopic rods 12 and transverse telescopic rods 13 are arranged adjacent to each other and fixedly connected end to end. Specifically, as shown... Figure 6 As shown, the connecting angle iron 10 has three perpendicular surfaces, each with a through hole. The ends of the longitudinal telescopic rod 11, the horizontal telescopic rod 12, and the transverse telescopic rod 13 are all provided with threaded sections. After the threaded sections of the longitudinal telescopic rod 11, the horizontal telescopic rod 12, and the transverse telescopic rod 13 are inserted into the through holes on the corresponding surfaces of the connecting angle iron 10, the threads are connected to the nuts. By tightening the nuts, the ends of the telescopic rods (longitudinal telescopic rod 11, horizontal telescopic rod 12, and transverse telescopic rod 13) can be connected to the connecting angle iron 10.

[0038] The collecting film sleeve 8 is made of transparent and soft plastic material, preferably polyethylene. The top of the collecting film sleeve 8 is provided with an air nozzle 9 for connecting the connecting tube 2.

[0039] When it is necessary to measure the ammonia volatilization of a plant canopy, assemble the support frame, cover the plant to be measured, and place the collecting film sleeve 8 on the support frame. The gas nozzle 2 9 is connected to the pump-type portable ammonia detector 1 via the connecting pipe 2, allowing for the measurement of the ammonia volatilization of that specific plant. By adjusting the height, lateral width, and longitudinal width of the support frame, it can be adapted to plants of different sizes. This adjustable method effectively expands the applicability of this solution. Multiple collecting film sleeves 8 can be prepared in gradients from small to large to accommodate different sizes of support frames; alternatively, only one largest size collecting film sleeve 8 can be prepared, allowing excess sleeves to be piled on the ground when measuring smaller plants. When relocation is required, disassemble the connecting pipe 2, remove the collecting film sleeve 8, and disassemble the longitudinal telescopic rod 11, horizontal telescopic rod 12, lateral telescopic rod 13, and connecting angle iron 10 for storage. This method further reduces the space occupied, making it easier to move and transport. This adjustable size method is mainly suitable for plants such as corn and sorghum, whose height increases significantly over time.

[0040] like Figure 7 As shown, as an improved method for connecting the telescopic rods (longitudinal telescopic rod 11, horizontal telescopic rod 12, and transverse telescopic rod 13) to the connecting angle iron 10 in this embodiment, unlike the above, a locking slot is opened on each of the three perpendicular surfaces of the connecting angle iron 10. The ends of the longitudinal telescopic rod 11, the horizontal telescopic rod 12, and the transverse telescopic rod 13 are all connected to locking posts with annular grooves. The locking posts at the ends of the longitudinal telescopic rod 11, the horizontal telescopic rod 12, and the transverse telescopic rod 13 are locked into the locking slots on the corresponding surfaces of the connecting angle iron 10. By pressing or pulling, the ends of the telescopic rods (longitudinal telescopic rod 11, horizontal telescopic rod 12, and transverse telescopic rod 13) can be connected to the connecting angle iron 10 through the aforementioned locking method. Compared with the connection method of threaded section nuts, this method is faster to connect and easier to disassemble and assemble.

[0041] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A device for in-situ measurement of ammonia volatilization from plant canopy, characterized in that: It includes a pump-type portable ammonia detector (1), a connecting pipe (2), and a gas collection chamber (3); A pump-suction portable ammonia detector (1) has an air inlet for measuring the concentration of ammonia. The gas collection chamber (3) is a closed structure used to cover the plant to be tested and has an air outlet. The connecting pipe (2) is connected at one end to the air inlet of the pump-type portable ammonia detector (1) and at the other end to the air outlet of the gas collection chamber (3). The gas collection chamber (3) includes a cylindrical body and a top cover (4). The top cover (4) is fastened to the top of the cylindrical body. A gas nozzle (6) is provided at the top of the top cover (4) for connecting the other end of the connecting pipe (2). The cylindrical body is formed by rolling up a flexible plate (5), and magnets (7) that attract each other are provided on opposite sides of the flexible plate (5).

2. The device for in-situ measurement of canopy ammonia volatilization according to claim 1, characterized in that: The flexible plate (5) is made of polyvinyl chloride, polyethylene or thermoplastic polyurethane elastomer.

3. The in-situ device for measuring ammonia volatilization in plant canopies according to claim 1, characterized in that: The gas collection chamber (3) includes a support frame and a collection film sleeve (8) fitted on the support frame. The collection film sleeve (8) is provided with a second air nozzle (9) for connecting the other end of the connecting pipe (2).

4. The device for in-situ measurement of canopy ammonia volatilization according to claim 3, characterized in that: The support frame includes a top frame, a bottom frame, and a longitudinal telescopic rod (11) connecting the top frame and the bottom frame, wherein there are at least two longitudinal telescopic rods (11).

5. The device for in-situ measurement of canopy ammonia volatilization according to claim 4, characterized in that: The top frame and / or bottom frame are formed by connecting horizontal telescopic rods (12) and transverse telescopic rods (13) end to end with connecting angle irons (10).

6. The device for in-situ measurement of canopy ammonia volatilization according to claim 5, characterized in that: The connecting angle iron (10) has three mutually perpendicular connecting surfaces, and a through hole is opened on each connecting surface; The ends of the longitudinal telescopic rod (11), the horizontal telescopic rod (12), and the transverse telescopic rod (13) are all provided with external thread sections; The external threaded section passes through the corresponding through hole and is locked with a nut, so that the longitudinal telescopic rod (11), the horizontal telescopic rod (12) and the transverse telescopic rod (13) are respectively fixedly connected to the connecting angle iron (10).

7. The device for in-situ measurement of canopy ammonia volatilization according to claim 5, characterized in that: The connecting angle iron (10) has three mutually perpendicular connecting surfaces, and a bayonet is provided on each connecting surface; The ends of the longitudinal telescopic rod (11), the horizontal telescopic rod (12) and the transverse telescopic rod (13) are all provided with snap-fit ​​posts with ring grooves; The snap-fit ​​pin engages with the corresponding snap-fit ​​slot, so that the longitudinal telescopic rod (11), the horizontal telescopic rod (12) and the transverse telescopic rod (13) are respectively fixedly connected to the connecting angle iron (10).

8. The in-situ device for measuring ammonia volatilization in plant canopies according to any one of claims 3-7, characterized in that: The material of the collecting film sleeve (8) is polyethylene, polyvinyl chloride or ethylene-vinyl acetate copolymer.

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