A wetland soil moisture collection device

Abstract

The application discloses a kind of wetland soil moisture collection devices, including sampling probe, operating handle and negative pressure suction component.Sampling probe uses coaxial nested hollow inner rod and outer rod, the side wall of both is respectively opened axial interval arrangement strip-shaped first, second sampling groove, groove position and size are correspondingly matched.Inner rod is equipped with coaxial hollow center axis, outer wall of shaft is equipped with chute corresponding each sampling groove, hollow telescopic rod driven by micro linear motor is assembled in chute; telescopic rod bottom end is equipped with sleeve pipe transversely, sampling probe is connected by telescopic cylinder, and probe is towards sampling groove opening.Negative pressure suction component contains negative pressure main pipe in center axis, first vacuum air pump, flow collector and sample collection bottle, main pipe is connected each sampling probe through branch pipe, flow collector is connected probe and sample collection bottle, and directional collection and collection of layered soil moisture are realized.The device realizes accurate layered directional collection of wetland soil moisture, avoids sample cross contamination, can protect sampling component, and improve sample purity.

Description

Technical Field

[0001] This invention relates to the field of soil sample collection technology, and more specifically to a wetland soil moisture collection device. Background Technology

[0002] As an important ecosystem, the content, distribution, and interlayer differences of soil moisture in wetlands are core indicators for studying wetland eco-hydrological processes, vegetation growth patterns, soil physicochemical properties, and ecosystem stability. Wetland soils are characterized by high water content, high porosity, heavy clay texture, and susceptibility to siltation. Furthermore, the soil structure is complex, with significant differences in the physical properties of soil moisture and solute content at different depths.

[0003] Existing wetland soil moisture sampling devices are mainly divided into two categories: traditional manual samplers and simple negative pressure sampling devices. Both suffer from numerous technical shortcomings in practical applications, failing to meet the demands for precise and stratified sampling. Traditional manual samplers are mostly one-piece metal tube structures. During sampling, the entire probe must be inserted into the soil layer to extract the soil sample and then separate the moisture. This is not only cumbersome and labor-intensive, but also prone to mixing soils from different layers during sampling, leading to cross-contamination of moisture samples. It cannot achieve targeted sampling of moisture at specific depths, significantly reducing the accuracy and representativeness of the collected data. Furthermore, the high resistance when the metal tube probe is inserted into the heavy clay soil of wetlands can easily damage the soil structure, altering the original distribution of soil moisture and affecting the reliability of the test results.

[0004] While existing simple negative pressure sampling devices can extract and collect soil moisture through negative pressure, reducing soil sample mixing to some extent, they still have significant technical shortcomings: First, most devices lack stratified sampling design and can only collect soil moisture at a single depth. To obtain samples from different soil layers, the probe must be inserted and removed multiple times, which is not only inefficient but also prone to creating sampling channels in the soil, causing deep water to seep upwards and resulting in sampling errors. Second, the sampling components of the devices lack effective protective structures. When the probe is inserted into and pulled out of the soil, the sampling port is easily buried or scraped by the soil, which not only damages the sampling components but also introduces a large amount of impurities, affecting sample purity. Third, some stratified sampling devices have low precision in adjusting the sampling depth, poor stability in the extension and positioning of the sampling components, and cannot accurately align with the target soil layer. Furthermore, the layout of the negative pressure pipeline and the collection pipeline is chaotic, which easily leads to pipeline blockage and leakage, resulting in sample collection failure. Summary of the Invention

[0005] In view of the above-mentioned shortcomings in the prior art, the present invention provides a wetland soil moisture collection device that solves the problems of existing wetland soil moisture collection devices being unable to accurately collect samples in layers and directions, being prone to cross-contamination during sampling, having insufficient protection of sampling components that are easily damaged and contain impurities, and having low accuracy in adjusting sampling depth.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: a wetland soil moisture collection device, comprising a sampling probe, an operating handle connected to the top of the sampling probe, and a negative pressure suction component communicating with the inside of the sampling probe;

[0007] The sampling probe includes an inner rod and an outer rod arranged coaxially. The outer rod is rotatably sleeved on the outside of the inner rod. Both the inner rod and the outer rod are hollow round rods. The inner rod sidewall is provided with several first sampling grooves spaced apart along the axial direction. The first sampling groove is a long strip-shaped through groove. The outer rod sidewall is provided with a second sampling groove that matches the first sampling groove. The size of the second sampling groove is the same as that of the first sampling groove.

[0008] A hollow central shaft with a coaxial axis is fixedly installed inside the hollow cavity of the inner rod. Several sliding grooves are spaced apart along the axial direction on the outer wall of the central shaft. The number of sliding grooves is the same as the number of the first sampling grooves and their positions correspond one-to-one. A hollow telescopic rod is slidably installed in each sliding groove. The telescopic end of the telescopic rod passes through the first sampling groove. A micro linear motor is installed on the sliding groove and connected to the telescopic rod. The telescopic rod is driven by the micro linear motor and moves back and forth in the vertical direction along the sliding groove. A sleeve is fixed laterally at the bottom of the telescopic rod. A telescopic cylinder is installed inside the sleeve. A sampling probe is installed at the end of the telescopic cylinder away from the sleeve. The detection surface of the sampling probe corresponds to the opening direction of the first sampling groove.

[0009] The negative pressure suction assembly includes a negative pressure main pipe, a first vacuum pump, several manifolds, and several sample collection bottles. The negative pressure main pipe is a hollow tube set inside the central shaft. One end of the tube extends along the inside of the central shaft and passes through the top of the inner rod to extend outward. The outward-extending end is connected to the first vacuum pump. Several connection ports are opened on the tube wall inside the central shaft. The number of connection ports is the same as the number of telescopic rods and their positions correspond one-to-one. The connection ports are connected to the sampling probe through branch pipes.

[0010] The manifolds are arranged along the axial direction of the telescopic rod. Each manifold is connected to the sampling probe and the sample collection bottle. A second vacuum pump is also installed on the sample collection bottle.

[0011] Furthermore, the aforementioned wetland soil moisture collection device has a sampling probe that is an integrated multi-layered hollow cavity structure with an overall cylindrical shape. From the outside to the inside, the sampling probe is sequentially equipped with a stainless steel anti-clogging filter layer, a porous ceramic filter layer, and a hydrophilic and permeable filter membrane layer. The cavity is also equipped with a stainless steel mesh support frame.

[0012] Furthermore, in the aforementioned wetland soil moisture collection device, an open temporary water storage chamber is set inside the sampling probe, the end of the collection tube away from the sample collection bottle extends into the temporary water storage chamber, and the branch pipe is set outside the temporary water storage chamber.

[0013] Furthermore, the aforementioned wetland soil moisture collection device has a rotational positioning structure between the inner rod and the outer rod. The rotational positioning structure includes an annular positioning groove on the outer wall of the inner rod, a positioning ball on the inner wall of the outer rod that matches the annular positioning groove, and a compression spring for tightening the positioning ball. Rotating the outer rod can make the second sampling groove coincide with or stagger the first sampling groove, thereby enabling the sampling probe to extend for sampling or be retracted for protection.

[0014] Furthermore, the aforementioned wetland soil moisture collection device includes an operating handle comprising a connecting cover movably connected to the top of the sampling probe and a first grip and a second grip symmetrically disposed at both ends of the connecting cover. A first vacuum pump is fixedly disposed inside the first grip, and a built-in lithium battery is disposed inside the second grip for powering the telescopic cylinder, the micro linear motor, and the first vacuum pump.

[0015] Furthermore, in the aforementioned wetland soil moisture collection device, a puncture head is provided at the bottom of the sampling probe, which is threadedly connected to the bottom of the outer rod. The end of the puncture head away from the outer rod is provided with conical teeth along the circumference, and the outer wall of the puncture head is provided with spiral patterns to facilitate the sampling probe to be screwed into the wetland soil layer.

[0016] Furthermore, in the aforementioned wetland soil moisture collection device, an elastic locking component is provided along the direction of the telescopic rod on the central axis, and a locking groove is provided on the side of the sleeve facing the central axis. The elastic locking component matches the locking groove to achieve vertical locking and fixation of the telescopic rod.

[0017] Furthermore, the aforementioned wetland soil moisture collection device has a waterproof sealing ring between the inner and outer rods.

[0018] Furthermore, in the aforementioned wetland soil moisture collection device, the sample collection bottle is equipped with volume markings.

[0019] Furthermore, the aforementioned wetland soil moisture collection device has an integrated control panel on its operating handle for controlling a miniature linear motor, a telescopic cylinder, a first vacuum pump, and a second vacuum pump.

[0020] The beneficial effects of this invention are as follows: This device, through the integrated design of coaxial nested probes, precise control sampling components, and independent negative pressure collection system, achieves precise, stratified, and directional collection of wetland soil moisture, greatly improving the accuracy, efficiency, and stability of sampling, and is suitable for the characteristics of wetland soil that is heavy and prone to siltation.

[0021] The inner rod matches the outer rod, and the sampling trough is equipped with a telescopic rod driven by a micro linear motor to precisely adjust the sampling depth and target different soil layers. Each sampling probe is equipped with an independent negative pressure branch pipe and a manifold to form a layered independent pipeline system, which effectively avoids cross-contamination of samples.

[0022] The rotating positioning structure can accommodate the sampling probe, preventing it from being scraped or buried by the soil; the sampling probe has a multi-layer filter structure, which can filter impurities step by step, prevent pipeline blockage, and improve sample purity; the waterproof sealing ring between the inner and outer rods blocks the mud moisture and protects the internal components.

[0023] The puncture head with tapered teeth and spiral grooves reduces the resistance of the probe insertion, reduces labor intensity and minimizes damage to soil structure; the operating handle integrates an air pump, lithium battery and control panel to achieve integrated operation, and can complete multi-depth sampling with a single screw insertion, greatly improving work efficiency and avoiding sampling errors caused by multiple insertions and removals.

[0024] The elastic locking assembly secures the telescopic rod to prevent displacement during sampling; the temporary water storage chamber of the sampling probe forms a liquid flow buffer to avoid leakage and blockage in the pipeline; the graduated sample collection bottle facilitates control of the sampling volume and effectively reduces the sample collection failure rate. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the cross-sectional structure of the device;

[0026] Figure 2 This is a schematic diagram of the structure when the first sampling slot and the second sampling slot overlap.

[0027] Figure 3 This is a schematic diagram of the structure with the first and second sampling slots staggered.

[0028] Figure 4 for Figure 1 A magnified view of a portion at point A;

[0029] Figure 5 This is a schematic diagram of the cross-sectional structure of the sampling probe;

[0030] Figure 6 This is a partial structural diagram of the central axis and the sliding groove;

[0031] The components are as follows: 1. Sampling probe, 2. Operating handle, 3. Inner rod, 4. Outer rod, 5. First sampling slot, 6. Second sampling slot, 7. Central shaft, 8. Slide groove, 9. Telescopic rod, 10. Sleeve, 11. Sampling probe, 12. Negative pressure main pipe, 13. First vacuum pump, 14. Manifold, 15. Sample collection bottle, 16. Connection port, 17. Branch pipe, 18. Stainless steel anti-clogging filter layer, 19. Porous ceramic filter layer, 20. Hydrophilic and permeable filter membrane layer, 21. Support frame, 22. Temporary water storage chamber, 23. Connecting cap, 24. First grip, 25. Second grip, 26. Puncture head, 27. Conical teeth, 28. Spiral texture, 29. Elastic locking assembly, 30. Locking slide groove. Detailed Implementation

[0032] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0033] like Figures 1-6 As shown, this embodiment provides a wetland soil moisture collection device. The device includes a sampling probe 1, an operating handle 2 connected to the top of the sampling probe 1, and a negative pressure suction assembly communicating with the inside of the sampling probe 1. The components work together to achieve precise, stratified, and directional collection of wetland soil moisture.

[0034] The sampling probe 1 is a coaxial nested hollow structure, including an inner rod 3 and an outer rod 4 coaxially arranged. The outer rod 4 is rotatably sleeved on the outside of the inner rod 3. Both the inner rod 3 and the outer rod 4 are hollow round rods made of 304 stainless steel. A 3mm gap is reserved between the inner rod 3 and the outer rod 4. A fluororubber waterproof sealing ring is installed in the gap. The waterproof sealing ring is a ring structure and is respectively sleeved on the top, bottom and axial middle position of the inner rod 3, effectively preventing mud and water in the wetland soil from entering the gap between the inner rod 3 and the outer rod 4, protecting the internal components from pollution and corrosion.

[0035] In this embodiment, the inner rod 3 has three first sampling grooves 5 evenly spaced along the axial direction on its side wall. The first sampling grooves 5 are elongated through grooves that penetrate the side wall of the inner rod 3. The outer rod 4 has three second sampling grooves 6 that match the first sampling grooves 5 on its side wall. The dimensions of the second sampling grooves 6 are exactly the same as those of the first sampling grooves 5, and the axial spacing of the second sampling grooves 6 is the same as that of the first sampling grooves 5, so that when the outer rod 4 rotates relative to the inner rod 3, the second sampling grooves 6 can completely overlap or completely offset from the first sampling grooves 5.

[0036] A rotary positioning structure is provided between the inner rod 3 and the outer rod 4. The rotary positioning structure includes an annular positioning groove on the outer wall of the inner rod 3, a positioning ball on the inner wall of the outer rod 4 that matches the annular positioning groove, and a compression spring for pressing the positioning ball. The annular positioning groove is a circular groove that corresponds to the top, bottom, and axial middle positions of the inner rod 3. The inner wall of the outer rod 4 has mounting holes corresponding to each annular positioning groove. The mounting holes are evenly distributed around the circumference of the outer rod 4. The positioning ball and the compression spring are embedded in the mounting holes. The positioning ball is made of stainless steel, and the compression spring is a miniature compression spring. Under normal conditions, the compression spring presses the positioning ball, causing the positioning ball to be engaged in the annular positioning groove, thereby achieving relative positioning of the inner rod 3 and the outer rod 4. When the outer rod 4 is rotated, the positioning ball can roll along the annular positioning groove. When the rotation reaches the position where the second sampling groove 6 coincides with or is offset from the first sampling groove 5, the elastic force of the compression spring can achieve precise positioning of the outer rod 4 and prevent the outer rod 4 from shifting during the sampling process.

[0037] A coaxial hollow central shaft 7 is fixedly installed inside the hollow cavity of the inner rod 3. The central shaft 7 is made of hard aluminum alloy. Both ends of the central shaft 7 are fixedly connected to the top and bottom inner walls of the inner rod 3 through flanges to ensure that the coaxiality error between the central shaft 7 and the inner rod 3 does not exceed 0.1mm. Three sliding grooves 8 are spaced apart along the axial direction on the outer wall of the central shaft 7. The number of sliding grooves 8 is the same as the number of first sampling grooves 5 and their positions correspond one-to-one. The sliding grooves 8 are arc-shaped grooves that extend along the axial direction of the central shaft 7 and remain parallel to the corresponding first sampling grooves 5.

[0038] A hollow telescopic rod 9 is slidably installed in each chute 8. The telescopic rod 9 is a hollow round rod made of stainless steel. The telescopic end of the telescopic rod 9 passes through the first sampling groove 5, and the length of the extended end can be adjusted according to the sampling requirements. A miniature linear motor is fixedly installed on the chute 8. The miniature linear motor is a stepper type miniature linear motor. The output end of the miniature linear motor is rigidly connected to the fixed end of the telescopic rod 9. The telescopic rod 9 is driven by the miniature linear motor to move reciprocally in a linear motion in the vertical direction along the chute 8, so as to achieve precise adjustment of the sampling depth.

[0039] An elastic locking assembly 29 is provided along the direction of the telescopic rod 9 on the central shaft 7. The elastic locking assembly 29 includes a locking spring and a locking protrusion disposed on the side wall of the slide 8. The locking spring is a stainless steel elastic sheet, and the locking protrusion is a hemispherical structure. A locking slide 30 is provided on the side of the sleeve 10 facing the central shaft 7. The length is the same as that of the slide 8. Several locking slots are provided at equal intervals along the axial direction on the side wall of the locking slide 30. The locking slots are hemispherical grooves that match the locking protrusions. When the telescopic rod 9 moves to the target position along the slide 8, the locking protrusion of the elastic locking assembly 29 is engaged in the corresponding locking slot, thereby locking and fixing the telescopic rod 9 in the vertical direction and preventing the telescopic rod 9 from displacing due to soil resistance during the sampling process.

[0040] A sleeve 10 is horizontally fixed to the bottom of the telescopic rod 9. The sleeve 10 is a hollow round tube made of stainless steel and is welded and fixed to the telescopic rod 9 perpendicularly. A telescopic cylinder is fixedly installed inside the sleeve 10. The telescopic cylinder is a miniature pneumatic telescopic cylinder. The cylinder body of the telescopic cylinder is fixed with an interference fit to the inner wall of the sleeve 10. The end of the telescopic cylinder away from the sleeve 10 is fixedly connected to the sampling probe 11 through a flange. The detection surface of the sampling probe 11 corresponds to the opening direction of the first sampling groove 5, so that when the telescopic cylinder drives the sampling probe 11 to extend, the sampling probe 11 can be accurately aimed at the target soil layer.

[0041] The bottom end of the sampling probe 1 is equipped with a puncture head 26, which is made of high-strength alloy steel and is threaded to the bottom end of the outer rod 4. A sealing gasket is provided at the connection to ensure sealing. Eight conical teeth 27 are evenly arranged around the circumference of the end of the puncture head 26 away from the outer rod 4. The cone angle of the conical teeth 27 is 30°. The outer wall of the puncture head 26 is provided with spiral patterns 28 to facilitate the insertion of the sampling probe 1 into the wetland clay layer and reduce the insertion resistance.

[0042] The sampling probe 11 is an integrated multi-layer hollow cavity structure with an overall cylindrical shape. From the outside to the inside, the sampling probe 11 is provided with a stainless steel anti-clogging filter layer 18, a porous ceramic filter layer 19, and a hydrophilic and permeable filter membrane layer 20. The cavity is provided with a stainless steel mesh support frame 21. The support frame 21 is a mesh structure used to support each filter layer and prevent the filter layer from deforming due to negative pressure.

[0043] The sampling probe 11 has an open temporary water storage chamber 22 inside. The temporary water storage chamber 22 is a cylindrical cavity located in the axial middle of the sampling probe 11. The end of the manifold 14 away from the sample collection bottle 15 extends into the temporary water storage chamber 22. The branch pipe 17 is located outside the temporary water storage chamber 22 and is sealed to the cavity wall of the sampling probe 11. The temporary water storage chamber 22 can form a liquid flow buffer to avoid leakage and blockage of the pipeline when soil moisture is rapidly drawn by negative pressure.

[0044] The operating handle 2 includes a connecting cover 23 that is movably connected to the top of the sampling probe 1, and a first gripping part 24 and a second gripping part 25 symmetrically arranged at both ends of the connecting cover 23. The connecting cover 23 is made of aluminum alloy and is connected to the top of the inner rod 3 by threads. A waterproof sealing ring is provided at the connection between the connecting cover 23 and the sampling probe 1 to ensure the internal sealing. The surfaces of the first gripping part 24 and the second gripping part 25 are provided with anti-slip textures to facilitate the operator's grip.

[0045] The first vacuum pump 13 is fixedly installed inside the first grip 24. The first vacuum pump 13 is a miniature oil-free first vacuum pump 13. The air inlet of the first vacuum pump 13 is sealed to the protruding end of the negative pressure main pipe 12, and the air outlet extends to the outside of the first grip 24 to ensure the stability of negative pressure suction.

[0046] The second gripping part 25 is equipped with a built-in lithium battery for powering the telescopic cylinder, the micro linear motor and the first vacuum pump 13. The built-in lithium battery is a lithium iron phosphate battery and is equipped with a charging interface and a power display module. The charging interface is located at the end of the second gripping part 25, and the power display module is embedded in the outer wall of the second gripping part 25 so that the operator can easily check the remaining power. The built-in lithium battery provides stable power support for each electrical component, enabling portable operation of the device.

[0047] The operating handle 2 is equipped with an integrated control panel for controlling the micro linear motor, telescopic cylinder, and first vacuum pump 13. The integrated control panel is embedded in the outer wall of the second grip 25 and includes a power switch, a depth adjustment button, a telescopic control button, a negative pressure start button, and an emergency stop button. Each button is electrically connected to the control circuit of the micro linear motor, telescopic cylinder, and first vacuum pump 13. The depth adjustment button enables precise lifting and lowering adjustment of the telescopic rod 9. The telescopic control button controls the extension and retraction of the telescopic cylinder. The negative pressure start button controls the opening and closing of the first vacuum pump 13. The emergency stop button can cut off all power in an emergency to ensure operational safety.

[0048] The negative pressure suction assembly includes a negative pressure main pipe 12, a first vacuum pump 13, three manifolds 14 and three sample collection bottles 15. Each component forms an independent layered negative pressure collection system to ensure independent collection of soil moisture samples from each layer and avoid cross-contamination.

[0049] The negative pressure main pipe 12 is a hollow tube set inside the central shaft 7 and is coaxial with the central shaft 7. One end of the negative pressure main pipe 12 extends along the inside of the central shaft 7 and extends outward through the top of the inner rod 3, and is sealed to the air inlet of the first vacuum pump 13. The negative pressure main pipe 12 has 3 connection ports 16 on the pipe wall inside the central shaft 7. The number of connection ports 16 is the same as the number of telescopic rods 9 and their positions correspond one-to-one. The connection ports 16 are circular interfaces and are evenly distributed along the axial direction of the negative pressure main pipe 12.

[0050] The connection port 16 is connected to the sampling probe 11 through the branch pipe 17. The branch pipe 17 is a hollow flexible tube made of polytetrafluoroethylene. One end of the branch pipe 17 is sealed to the connection port 16, and the other end passes through the hollow cavity of the telescopic rod 9 and is sealed to the outside of the temporary water storage cavity 22 of the sampling probe 11. The connection between the branch pipe 17 and the telescopic rod 9 and the sampling probe 11 is sealed with sealant to ensure negative pressure sealing.

[0051] The manifold 14 is arranged axially along the telescopic rod 9. The manifold 14 is a hollow flexible tube made of transparent polyvinyl chloride, which has good corrosion resistance and transparency, making it easy to observe the liquid flow status. One end of each manifold 14 passes through the hollow cavity of the telescopic rod 9 and extends into the temporary water storage cavity 22 of the sampling probe 11. The other end passes through the operating handle 2 and is sealed to the sample collection bottle 15. Sealing joints are provided at the connection points of the manifold 14 with the telescopic rod 9, the operating handle 2, and the sample collection bottle 15 to ensure sealing and prevent leakage.

[0052] The sample collection bottle 15 is made of transparent glass and has volume markings on the body to facilitate operators in controlling the sampling volume. The bottle mouth of the sample collection bottle 15 is equipped with a threaded sealing cap, which is sealed to the manifold 14. The sample collection bottle 15 is detachable and replaceable, which facilitates the preservation and transportation of the collected samples.

[0053] In use, the operator holds the operating handle 2, aligns the piercing head 26 of the sampling probe 1 with the sampling point, and rotates the operating handle 2 to screw the sampling probe 1 into the wet soil layer through the spiral groove 28. After screwing into the preset depth, the operator controls the micro linear motor to drive the telescopic rod 9 to move along the slide groove 8 via the depth adjustment button on the integrated control panel to adjust to the target sampling depth. In this embodiment, the three telescopic rods 9 can be adjusted to different sampling depths. After the sampling depth is adjusted, the elastic locking component 29 locks and fixes the telescopic rod 9. Then, the operator rotates the outer rod 4 to make the second sampling groove 6 coincide with the first sampling groove 5, and controls the extension and retraction via the extension and retraction control button. The telescopic cylinder drives the sampling probe 11 to extend, so that the probe surface of the sampling probe 11 is aligned with the target soil layer; then the negative pressure start button is pressed to turn on the first vacuum pump 13 and the second vacuum pump. The negative pressure main pipe 12 generates negative pressure. Soil moisture is filtered through the multi-layer filter of the sampling probe 11 and enters the temporary water storage chamber 22. Then it flows into the corresponding sample collection bottle 15 through the collection pipe 14. The operator controls the sampling volume through the volume scale of the sample collection bottle 15. After sampling is completed, the operating handle 2 is rotated in the opposite direction to unscrew the sampling probe 1 out of the soil layer. The sample collection bottle 15 is disassembled for sample preservation, and the various parts of the device are cleaned and maintained.

[0054] This sampling device solves the problems of existing wetland soil moisture sampling devices, such as inability to accurately collect samples in layers and directions, easy cross-contamination of samples, lack of protection for sampling components that are easily damaged and contain impurities, and low accuracy of sampling depth adjustment.

[0055] The sampling probe 1 uses a coaxially nested inner rod 3 and outer rod 4, along with three axially equally spaced first and second sampling slots 6. A micro linear motor drives the telescopic rod 9 to move vertically along the slide 8. The elastic locking component 29 achieves precise locking of the telescopic rod 9, which can accurately adjust the sampling depth and align with different target soil layers. The three sets of sampling probes 11 are equipped with independent branch pipes 17, collection pipes 14 and sample collection bottles 15, forming a layered and independent negative pressure collection system, which effectively avoids cross-contamination of moisture samples from different soil layers and ensures the accuracy and representativeness of the collected data.

[0056] The rotational positioning structure between the inner rod 3 and the outer rod 4 allows the second sampling slot 6 to overlap or stagger with the first sampling slot 5. During sampling, the sampling probe 11 extends and is retracted after sampling, preventing the sampling probe 11 from being scraped or buried by the soil when the probe is inserted into and pulled out of the soil layer, thus preventing damage to the sampling components. The integrated multi-layer filter structure of the sampling probe 11 can filter large and small particles of impurities in the soil step by step, preventing pipeline blockage and improving sample purity. The waterproof sealing ring between the inner rod 3 and the outer rod 4 effectively blocks mud and water, protecting internal components such as the telescopic rod 9 and the micro linear motor from contamination and corrosion.

[0057] The piercing head 26 at the bottom of the sampling probe 1 is equipped with conical teeth 27 and spiral patterns 28, which greatly reduces the resistance of the probe when it is screwed into the heavy clay soil layer of wetland, reduces the labor intensity of operators, and the screw-in insertion method reduces damage to the soil structure and ensures the original distribution of soil moisture. The operating handle 2 integrates the first vacuum pump 13, built-in lithium battery and integrated control panel, realizing integrated control of power supply, negative pressure suction, sampling depth adjustment and extension of sampling probe 11. No external power supply or equipment is required, which is suitable for wetland field sampling environment. The device can collect soil moisture at multiple different depths with a single screw-in, avoiding the formation of sampling channels and the upward infiltration of deep water caused by repeated insertion and removal of the probe, effectively reducing sampling errors and greatly improving sampling efficiency.

[0058] The elastic locking component 29 can effectively fix the telescopic rod 9, preventing the telescopic rod 9 from shifting due to soil resistance during sampling and ensuring the stability of the sampling depth; the temporary water storage chamber 22 inside the sampling probe 11 forms a liquid flow buffer, avoiding leakage and blockage of the pipeline when soil moisture is rapidly drawn in by negative pressure; the transparent graduated sample collection bottle 15 allows operators to observe the liquid flow status in real time and control the sampling volume; the sealed connection between the collection tube 14 and each component ensures no leakage and effectively reduces the sample collection failure rate; the negative pressure suction component adopts a miniature oil-free first vacuum pump 13 to provide stable negative pressure and ensure the continuity of soil moisture extraction and collection.

[0059] This device enables precise, stratified, and targeted collection of soil moisture in wetlands, taking into account sampling accuracy, ease of operation, equipment stability, and sample purity. It is fully adapted to the characteristics of wetland soils, such as high water content, high porosity, and heavy, easily clogging soil, and can meet the needs of precise soil moisture sampling in fields such as wetland eco-hydrological process research and soil physicochemical property testing.

Claims

1. A wetland soil moisture collection device, characterized in that, Includes a sampling probe (1), an operating handle (2) connected to the top of the sampling probe (1), and a negative pressure suction assembly communicating with the inside of the sampling probe (1); The sampling probe (1) includes an inner rod (3) and an outer rod (4) arranged coaxially. The outer rod (4) is rotatably sleeved on the outside of the inner rod (3). Both the inner rod (3) and the outer rod (4) are hollow round rods. The inner rod (3) has a number of first sampling grooves (5) spaced apart along the axial direction on its side wall. The first sampling groove (5) is a long strip through groove. The outer rod (4) has a second sampling groove (6) that matches the first sampling groove (5) on its side wall. The size of the second sampling groove (6) is the same as that of the first sampling groove (5). A hollow central shaft (7) with a coaxial axis is fixedly installed in the hollow cavity of the inner rod (3). Several sliding grooves (8) are spaced apart along the axial direction on the outer wall of the central shaft (7). The number of sliding grooves (8) is the same as the number of the first sampling grooves (5) and their positions correspond one-to-one. A hollow telescopic rod (9) is slidably installed in each sliding groove (8). The telescopic end of the telescopic rod (9) passes through the first sampling groove (5). A micro linear motor is installed on the sliding groove (8). The micro linear motor is connected to the telescopic rod (9). The telescopic rod (9) is driven by the micro linear motor and moves back and forth in the vertical direction along the sliding groove (8). A sleeve (10) is fixed horizontally at the bottom of the telescopic rod (9). A telescopic cylinder is installed inside the sleeve (10). A sampling probe (11) is installed at the end of the telescopic cylinder away from the sleeve (10). The detection surface of the sampling probe (11) corresponds to the opening direction of the first sampling groove (5). The negative pressure suction assembly includes a negative pressure main pipe (12), a first vacuum pump (13), several manifolds (14), and several sample collection bottles (15); the negative pressure main pipe (12) is a hollow tube set inside the central shaft (7), one end of which extends along the interior of the central shaft (7) and extends outward through the top of the inner rod (3), and the outwardly extended end is connected to the first vacuum pump (13); the negative pressure main pipe (12) has several connection ports (16) on the tube wall inside the central shaft (7), the number of connection ports (16) is the same as the number of telescopic rods (9) and their positions correspond one-to-one, and the connection ports (16) are connected to the sampling probe (11) through branch pipes (17); The manifold (14) is arranged axially along the telescopic rod (9). Each manifold (14) is connected to the sampling probe (11) and the sample collection bottle (15). A second vacuum pump is also provided on the sample collection bottle.

2. The wetland soil moisture collection device according to claim 1, characterized in that, The sampling probe (11) is an integrated multi-layer filter hollow cavity structure, which is cylindrical in shape. The sampling probe (11) is provided with a stainless steel anti-clogging filter layer (18), a porous ceramic filter layer (19), and a hydrophilic and water-permeable filter membrane layer (20) from the outside to the inside. The cavity is provided with a stainless steel mesh support skeleton (21).

3. The wetland soil moisture collection device according to claim 2, characterized in that, The sampling probe (11) has an open temporary water storage chamber (22) inside. The end of the manifold (14) away from the sample collection bottle (15) extends into the temporary water storage chamber (22). The branch pipe (17) is located outside the temporary water storage chamber (22).

4. The wetland soil moisture collection device according to claim 1, characterized in that, A rotary positioning structure is provided between the inner rod (3) and the outer rod (4). The rotary positioning structure includes an annular positioning groove on the outer wall of the inner rod (3), a positioning ball on the inner wall of the outer rod (4) that matches the annular positioning groove, and a compression spring for pressing the positioning ball. Rotating the outer rod (4) can make the second sampling groove (6) coincide with or stagger the first sampling groove (5), so as to realize the extension sampling or the storage protection of the sampling probe (11).

5. The wetland soil moisture collection device according to claim 1, characterized in that, The operating handle (2) includes a connecting cover (23) movably connected to the top of the sampling probe (1) and a first grip (24) and a second grip (25) symmetrically arranged at both ends of the connecting cover (23). The first vacuum pump (13) is fixedly arranged inside the first grip (24), and the second grip (25) is provided with a built-in lithium battery for powering the telescopic cylinder, the micro linear motor and the first vacuum pump (13).

6. The wetland soil moisture collection device according to claim 1, characterized in that, The sampling probe (1) is provided with a puncture head (26) at the bottom end. The puncture head (26) is threaded to the bottom end of the outer rod (4). The end of the puncture head (26) away from the outer rod (4) is provided with conical teeth (27) along the circumference. The outer wall of the puncture head (26) is provided with spiral patterns (28) to facilitate the sampling probe (1) to be screwed into the wetland soil layer.

7. The wetland soil moisture collection device according to claim 1, characterized in that, The central shaft (7) is provided with an elastic locking component (29) along the direction of the telescopic rod (9). The sleeve (10) is provided with a locking groove (30) on the side facing the central shaft (7). The elastic locking component (29) matches the locking groove to achieve vertical locking and fixing of the telescopic rod (9).

8. The wetland soil moisture collection device according to claim 1, characterized in that, A waterproof sealing ring is provided between the inner rod (3) and the outer rod (4).

9. The wetland soil moisture collection device according to claim 1, characterized in that, The sample collection bottle (15) has volume markings on its body.

10. The wetland soil moisture collection device according to any one of claims 1 to 9, characterized in that, The operating handle (2) is equipped with an integrated control panel for controlling the micro linear motor, telescopic cylinder, first vacuum pump (13), and second vacuum pump.

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