Sampling device for gas pollutant detection

Abstract

The invention relates to the technical field of gas sampling, and discloses a sampling device for gas pollutant detection, which comprises a base, a connecting cylinder is rotatably arranged on the base, a lifting seat capable of sliding up and down is arranged in the connecting cylinder, a plurality of mounting seats are equidistantly arranged on the lifting seat along the circumferential direction of the lifting seat, each mounting seat is provided with a detachable sampling assembly, and the sampling assemblies are arranged on the lifting seat. The sampling assembly comprises a sampling cylinder arranged on the mounting seat, each end cover is provided with an air suction port communicated with the interior of the sampling cylinder, a plurality of air suction ports which are spaced from one another are provided with air suction pipes I, and the rest of the plurality of air suction ports are provided with air suction pipes II; the lifting base is provided with a control assembly for the first air suction pipes or the second air suction pipes to conduct independent or simultaneous air suction. The gas sampling device is simple in structure, gas in multiple directions at the same place can be conveniently and rapidly sampled, the number of sampling points can be increased or decreased according to requirements, and therefore the use efficiency of the device is improved.

Description

Technical Field

[0001] This invention relates to the field of gas sampling technology, specifically to a sampling device for detecting gaseous pollutants. Background Technology

[0002] Air pollution refers to the phenomenon where the concentration of pollutants in gases reaches harmful levels, damaging ecosystems and hindering normal human survival and development. Sampling of gaseous pollutants is a crucial step in atmospheric environmental monitoring, significantly impacting the reliability of monitoring data. There are two main methods for collecting gaseous pollutant samples: one involves passing a large volume of air through a liquid or solid absorbent to absorb or retain pollutants, concentrating pollutants that were initially at low concentrations in the gas; the other involves using sampling tubes to collect air containing pollutants.

[0003] When using multiple sampling tubes to sample the atmosphere at the same location from multiple directions, the existing method requires manually attaching a sealing cap to the end of the sampling tube after sampling is complete. This is cumbersome and affects the ease of use of the device. Furthermore, the number of sampling points cannot be adjusted according to needs during the sampling process, which reduces the applicability of the device. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned difficulties and provide a sampling device for detecting gaseous pollutants.

[0005] To solve the above technical problems, the technical solution provided by the present invention is as follows: including a base, a connecting cylinder is rotatably provided on the top surface of the base, a lifting seat that can slide up and down is provided inside the connecting cylinder, and multiple mounting seats are provided equidistantly along the circumferential direction on the lifting seat, and multiple sampling components are provided on each mounting seat;

[0006] The sampling assembly includes a detachable sampling tube mounted on a mounting base. One end of the sampling tube is fixedly provided with an end cap, and the other end is slidably provided with a sealing cap. A piston rod is slidably provided on the end cap, and a piston that cooperates with the inner wall of the sampling tube is provided on the piston rod. Both ends of the sealing cap are provided with sliding rods that are slidably cooperate with the end cap. The ends of the two sliding rods that extend out of the end cap are provided with a connecting seat. The connecting seat and the end cap are provided with a connecting assembly that fixes the two together. A return spring is wound on the sliding rod between the connecting seat and the end cap. The piston rod is provided with a push block that releases the connecting assembly.

[0007] Each of the multiple end caps spaced apart from each other is provided with a detachable air intake pipe 1, and the remaining multiple end caps are provided with a detachable air intake pipe 2. The lifting seat is provided with a control component for the multiple air intake pipes 1 or 2 to perform individual or simultaneous air intake.

[0008] As an improvement, the control assembly includes a control cylinder mounted on a lifting seat. A rotating shaft is rotatably inserted through one end of the control cylinder, and a sealing seat that mates with the inner wall of the control cylinder is mounted on the rotating shaft. Under the action of the sealing seat, the control cylinder is divided into two independent suction cylinders: suction cylinder one and suction cylinder two. The other end of multiple suction pipes one is connected to suction cylinder one and communicates with its interior. The other end of multiple suction pipes two is connected to suction cylinder two and communicates with its interior.

[0009] A suction pipe three is provided on the control cylinder corresponding to the sealing seat, and through holes one, two and three are provided at equal intervals along the circumference of the sealing seat, which are connected to the suction pipe three. Through hole one is a T-shaped structure that is connected to the suction cylinder one and suction cylinder two at both ends respectively. Through holes two and three are L-shaped structures arranged in opposite directions that are connected to the suction cylinder one and suction cylinder two respectively. The lifting seat is provided with an adjustment component that controls the rotation of the rotating shaft one.

[0010] As an improvement, the adjustment assembly includes a worm gear disposed on the outer end of the rotating shaft, and fixed seats are provided on the lifting seats corresponding to both ends of the worm gear. A worm gear meshing with the worm gear is disposed on both fixed seats, and the end of the worm gear extending out of either fixed seat is connected to the output shaft of the motor. The lifting seat is provided with a detection assembly for controlling the rotation angle of the worm gear.

[0011] As an improvement, the detection assembly includes an L-shaped support rod mounted on a lifting seat. The support rod has a disc corresponding to the worm gear. Three detection blocks are equidistantly arranged along the circumference of the outer end face of the worm gear. A U-shaped frame is provided on the disc corresponding to any one of the detection blocks. The U-shaped frame is equipped with a proximity switch that works in conjunction with the detection block.

[0012] As an improvement, three positioning seats are provided at equal intervals along the circumference on the outer surface of the base, and a hinge seat is provided on the base in the middle between every two positioning seats. A detachable tripod is provided on all three hinge seats.

[0013] As an improvement, the bottom surface of the connecting cylinder is detachably provided with a bottom cover that rotates with the base, a large gear is sleeved on the outer side of the bottom cover, and a small gear that meshes with the large gear is rotatably provided on the base.

[0014] As an improvement, electric push rods are provided at both ends of the bottom cover, and the movable ends of the two electric push rods are respectively connected to the bottom surface of the lifting seat.

[0015] The advantages of this invention compared to the prior art are as follows:

[0016] 1. Controlling multiple suction tubes (I and II) to perform suction operations creates a negative pressure space inside the corresponding sampling tubes. At this time, external air enters the sampling tube from the bottom, which then pushes the piston inward. This causes the piston rod and push block to move inward synchronously. When the piston moves inward to contact the end cap, the push block pushes and adjusts the connecting seat, releasing the fixation between the connecting seat and the end cap. Under the action of the return spring, the sealing cap moves quickly towards the bottom wall of the sampling tube, automatically sealing the sampling tube after sampling. This allows for convenient and quick sampling of the atmosphere from multiple directions at the same location.

[0017] 2. By adjusting the control components, multiple suction tubes (I and II) can perform individual or simultaneous suction operations, thereby allowing for adaptive adjustments to the number of sampling tubes used as needed, thus improving the applicability of this device.

[0018] 3. Start the motor to drive the worm gear to rotate, which in turn drives the worm wheel and the shaft to rotate. At the same time, the sealing seat rotates in the control cylinder, so that the through hole one, through hole two or through hole three can selectively connect with the suction pipe four, thereby enabling the individual or simultaneous suction control of multiple suction pipes one or two.

[0019] 4. With the help of the proximity switch and the detection block, the angular position of the worm gear rotation can be effectively detected, and the angular position of the sealing seat rotation can also be effectively detected, ensuring the accuracy of the connection between the through hole one, through hole two or through hole three and the intake pipe three. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 .

[0021] Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2 .

[0022] Figure 3 This is a structural diagram of the invention.

[0023] Figure 4 This is a diagram of the internal structure of the present invention.

[0024] Figure 5 This is a schematic diagram of the cooperation between the sampling tube and the mounting base in this invention.

[0025] Figure 6 This is a diagram of the internal structure of the sampling tube in this invention.

[0026] Figure 7 This is a schematic diagram of the sampling tube in this invention.

[0027] Figure 8 This is a schematic diagram showing the connection between the first and second inhalation tubes in this invention.

[0028] Figure 9 This is a diagram of the internal structure of the control cylinder in this invention.

[0029] Figure 10 This is a schematic diagram of the sealing seat structure in this invention. Figure 1 .

[0030] Figure 11 This is a schematic diagram of the sealing seat structure in this invention. Figure 2 .

[0031] Figure 12 This is a schematic diagram of the connection between the control cylinder and the vacuum pump in this invention.

[0032] Figure 13 This is a schematic diagram of the structure of the adjustment component in this invention.

[0033] Figure 14 This is the present invention. Figure 13 Enlarged view of point A in the middle.

[0034] As shown in the figure: 1. Base; 111. Connecting cylinder; 112. Lifting seat; 113. Mounting seat; 114. Through groove; 115. Bottom cover; 116. Electric push rod; 117. Large gear; 118. Rotating shaft two; 119. Small gear; 120. Motor two; 121. Arc groove; 122. Arc seat; 123. Fastening screw; 124. Top cover; 125. Positioning seat; 126. Hinge seat; 2. Sampling assembly; 211. Sampling cylinder; 212. End cover; 213. Slide rod; 214. Sealing cover; 215. Sealing block; 216. Sealing ring; 217. Vent plug; 218. Piston rod; 219. Piston; 220. Connecting seat; 221. Through hole; 222. Return spring; 223. Connecting assembly; 2231. Magnetic block; 2232. Iron block; 224. Groove; 225. Push block; 226. Air intake port; 227. Air intake pipe one; 228. Air intake pipe two; 3. Control assembly; 311. Control cylinder; 312. Rotating shaft one; 313. Sealing seat; 314. Air intake cylinder one; 315. Air intake cylinder two; 316. Air intake pipe three; 317. Through hole one; 318. Through hole two; 319. Through hole three; 4. Adjustment assembly; 411. Worm gear; 412. Fixed seat; 413. Worm; 414. Motor one; 5. Detection assembly; 511. Support rod; 512. Disc; 513. Detection block; 514. U-shaped frame; 515. Proximity switch; 6. Air pump; 611. Air extraction pipe; 7. Tripod. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings.

[0036] Combined with appendix Figure 2 Appendix Figure 3 Appendix Figure 4 Appendix Figure 5 Appendix Figure 6 Appendix Figure 7 and attached Figure 8 As shown, a sampling device for detecting gaseous pollutants includes a base 1, a connecting cylinder 111 rotatably disposed on the top surface of the base 1, a lifting seat 112 that can slide up and down disposed inside the connecting cylinder 111, a plurality of L-shaped mounting seats 113 are equidistantly disposed on the lifting seat 112 along its circumference, a through groove 114 is provided on the connecting cylinder 111 corresponding to each mounting seat 113, and a detachable sampling component 2 is disposed on each mounting seat 113;

[0037] The sampling assembly 2 includes a detachable sampling cylinder 211 mounted on a mounting base 113. The mounting base 113 has an arc-shaped groove 121 for placing the sampling cylinder 211, and is also hinged to an arc-shaped seat 122 that mates with the arc-shaped groove 121. A fastening screw 123 passes through the arc-shaped seat 122 away from the hinge. The mounting base 113 has an internal thread that mates with the fastening screw 123. The sampling cylinder is sampled under the cooperation of the arc-shaped seat 122 and the arc-shaped groove 121. 211 is detachably connected. One end of the sampling tube 211 is fixedly provided with an end cap 212, and the other end is slidably provided with a sealing cap 214. A sealing block 215 that can extend into the sampling tube 211 and form a sealing state is fixedly provided on the sealing cap 214, and a sealing ring 216 is sleeved on the sealing block 215. A detachable vent plug 217 is provided on the sealing cap 214. The air in the sampling tube 211 after sampling can be discharged and tested through the vent plug 217.

[0038] A piston rod 218 is slidably mounted on the end cap 212, and a piston 219 is mounted on the piston rod 218 to cooperate with the inner wall of the sampling cylinder 211. Both ends of the sealing cap 214 are provided with sliding rods 213 that slidably cooperate with the end cap 212. The ends of the two sliding rods 213 extending out of the end cap 212 are provided with a connecting seat 220. A connecting assembly 223 is provided on the connecting seat 220 and the end cap 212 to fix them together. The connecting assembly 223 includes magnetic blocks 2231 disposed at both ends of the connecting seat 220. The end cap 212 is fixed... An iron block 2232 is provided to cooperate with the magnetic block 2231. With the cooperation of the magnetic block 2231 and the iron block 2232, the sealing cover 214 and the bottom of the sampling tube 211 are separated. A return spring 222 is wound on the slide rod 213 between the connecting seat 220 and the end cover 212. The connecting seat 220 is provided with a through hole 221 for the piston rod 218 to extend out. The piston rod 218 is provided with a push block 225 to release the connection assembly 223. The end cover 212 is provided with a slot 224 for the push block 225 to extend out.

[0039] Each end cap 212 has an air intake 226 that communicates with the inside of the sampling tube 211. Each of the multiple air intakes 226 that are spaced apart from each other is provided with a detachable first air intake tube 227. The remaining multiple air intakes 226 are provided with a detachable second air intake tube 228. The connection between the multiple first air intake tubes 227, the second air intake tubes 228 and the air intakes 226 is made by quick-connect couplings. This makes it easy to detach and connect the sampling tube 211 to the first air intake tubes 227 and the second air intake tubes 228. The lifting seat 112 is provided with a control component 3 for the multiple first air intake tubes 227 or the second air intake tubes 228 to perform air intake individually or simultaneously.

[0040] Through the above structure, the sealing cap 214 and the sampling tube 211 are first separated. Then, the piston 219 is moved away from the end cap 212. Next, multiple sampling tubes 211 are connected to the mounting base 113. Then, multiple suction tubes 1 227 and suction tube 228 are connected to the suction port 226. By controlling the multiple suction tubes 1 227 and suction tube 228 to perform individual or simultaneous suction operations, a negative pressure space can be formed inside the corresponding sampling tube 211. Since the pressure inside the sampling tube 211 is lower than the external atmospheric pressure, external air will enter through the sampling tube 211. The sampler enters the sampling cylinder 211 through the space between the bottom wall and the sealing cover 214. Then, the piston 219 is lifted and moved inward, which drives the piston rod 218 and the push block 225 to move inward synchronously. When the piston 219 moves inward to contact the end cover 212, the push block 225 pushes and adjusts the connecting seat 220, so that the fixing between the connecting seat 220 and the end cover 212 is released. Under the action of the return spring 222, the sealing cover 214 automatically moves towards the bottom wall of the sampling cylinder 211 to seal the sampling cylinder 211 after sampling.

[0041] Combined with appendix Figure 6 Appendix Figure 9 Appendix Figure 10 Appendix Figure 11 and attached Figure 12 As shown, the control component 3 includes a control cylinder 311 mounted on the lifting seat 112. A rotating shaft 312 is rotatably inserted through any end of the control cylinder 311, and a sealing seat 313 that cooperates with the inner wall of the control cylinder 311 is provided on the rotating shaft 312. Under the action of the sealing seat 313, the control cylinder 311 is divided into two independent suction cylinders 314 and 315. The other ends of multiple suction pipes 227 are connected to suction cylinder 314 and communicate with its interior, and the other ends of multiple suction pipes 228 are connected to suction cylinder 315 and communicate with its interior.

[0042] A suction pipe 316 communicating with the interior of the control cylinder 311 corresponding to the sealing seat 313 is provided. An air pump 6 is provided on the lifting seat 112. The suction port end of the air pump 6 is provided with an air pump 611 connected to the suction pipe 316. The sealing seat 313 is provided with through holes 317, 318 and 319 communicating with the suction pipe 316 at equal intervals along its circumference. The through hole 317 is a T-shaped structure that communicates with the suction cylinders 314 and 315 at both ends respectively. The through holes 318 and 319 are L-shaped structures arranged in opposite directions that communicate with the suction cylinders 314 and 315 respectively. The lifting seat 112 is provided with an adjustment component 4 for controlling the rotation of the rotating shaft 312.

[0043] The working principle of the control component 3 is as follows: the rotation of the rotating shaft 312 drives the sealing seat 313 to rotate inside the control cylinder 311, so that its through hole 317, through hole 318 or through hole 319 can selectively connect with the suction pipe 316. Then, the pump 6 is started. With the cooperation of the suction pipe 611 and the suction pipe 316, multiple suction pipes 227 and 228 can be suctioned individually or simultaneously. Thus, the number of sampling cylinders 211 can be increased or decreased according to the usage requirements, which improves the application range of this device.

[0044] Combined with appendix Figure 13 and attached Figure 14 As shown, the adjustment assembly 4 includes a worm gear 411 disposed on the outer end of the rotating shaft 312. Fixed seats 412 are provided on the lifting seats 112 corresponding to both ends of the worm gear 411. A worm 413 that meshes with the worm gear 411 is rotatably disposed on both fixed seats 412. The end of the worm 413 that extends out of either fixed seat 412 is connected to the output shaft of the motor 414. A detection assembly 5 for controlling the rotation angle of the worm gear 411 is provided on the lifting seat 112.

[0045] The detection component 5 includes an L-shaped support rod 511 mounted on the lifting seat 112. The support rod 511 is provided with a disc 512 corresponding to the worm gear 411. Three detection blocks 513 are equidistantly arranged on the outer end face of the worm gear 411 along its circumference. A U-shaped frame 514 is provided on the disc 512 corresponding to any one of the detection blocks 513. The U-shaped frame 514 is provided with a proximity switch 515 that works in conjunction with the detection block 513.

[0046] The working principle of adjustment component 4 and detection component 5 is as follows: the starting motor 414 drives the worm 413 to rotate, which in turn drives the meshing worm wheel 411 and the rotating shaft 312 to rotate. At the same time, the sealing seat 313 is rotated and adjusted. The cooperation between the worm wheel 411 and the worm 413 not only achieves the transmission function, but also achieves a certain self-locking effect. During the rotation of the worm wheel 411, the angle position of the rotation of the worm wheel 411 can be effectively detected by the cooperation of the detection block 513 and the proximity switch 515. At the same time, the rotation angle of the sealing seat 313 can be effectively detected, ensuring the accuracy of the connection between the through hole 317, the through hole 318 or the through hole 319 and the suction pipe 316.

[0047] Combined with appendix Figure 1 and attached Figure 2 As shown, three positioning seats 125 are equidistantly arranged on the outer side of the base 1 along its circumference. Each positioning seat 125 has a positioning hole. A hinge seat 126 is provided on the base 1 in the middle between every two positioning seats 125. A detachable tripod 7 is provided on all three hinge seats 126. This allows the base 1 to be connected to the tripod 7 or placed on a support frame during use, increasing the flexibility of the device.

[0048] Combined with appendix Figure 3 and attached Figure 6 As shown, the bottom surface of the connecting cylinder 111 is detachably provided with a bottom cover 115 that rotates with the base 1, and the top surface is provided with a detachable top cover 124. A large gear 117 is sleeved on the outer side of the bottom cover 115. A rotating shaft 118 is rotatably passed through the base 1. A small gear 119 that meshes with the large gear 117 is provided on the rotating shaft 118. The top end of the rotating shaft 118 is connected to the output shaft of the motor 120. When the motor 120 is started, the rotating shaft 118 and the small gear 119 are driven to rotate, which in turn drives the large gear 117 to rotate, thereby adjusting the rotation of the bottom cover 115 and the connecting cylinder 111.

[0049] Both ends of the bottom cover 115 are provided with electric push rods 116. The movable ends of the two electric push rods 116 are respectively connected to the bottom surface of the lifting seat 112. Both ends of the lifting seat 112 are fixed with sliders. The inner wall of the connecting cylinder 111 is provided with a sliding groove that matches the slider along its axial direction. By controlling the extension and retraction of the electric push rods 116, the lifting seat 112 can be adjusted up and down within the connecting cylinder 111, thereby effectively adjusting the height of the sampling cylinder 211.

[0050] In practical implementation, the tripod 7 is first selectively connected according to the requirements of the application environment. Then, the sampling tube 211 is connected to the mounting base 113. Controlling the rotation of the connecting tube 111 allows for adaptive adjustment of the sampling tube 211's direction. Finally, the vacuum pump 6 is activated. Under the action of the vacuum pipe 611 and the control component 3, multiple suction pipes 227 and 228 can be suctioned individually or simultaneously, creating a negative pressure space within the corresponding sampling tube 211. At this time, external air will flow from the sampling tube 211. The bottom of the 11 enters, simultaneously pushing the piston 219 to move inward, which in turn drives the piston rod 218 and the push block 225 to move inward. During the movement of the push block 225, the fixation between its connecting seat 220 and end cover 212 is released. Then, under the action of the return spring 222, its sealing cover 214 moves towards the bottom wall of the sampling tube 211, sealing the sampling tube 211 after sampling. This allows for convenient and quick sampling of the atmosphere from multiple directions at the same location, improving the efficiency of the device.

[0051] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A sampling device for detecting gaseous pollutants, comprising a base (1), wherein a connecting cylinder (111) is rotatably provided on the top surface of the base (1), and a lifting seat (112) that can slide up and down is provided inside the connecting cylinder (111). Multiple mounting seats (113) are equidistantly arranged along the circumferential direction on the lifting seat (112), and a sampling component (2) is provided on each mounting seat (113), characterized in that: The sampling assembly (2) includes a detachable sampling tube (211) mounted on a mounting base (113). One end of the sampling tube (211) is fixedly provided with an end cap (212), and the other end is slidably provided with a sealing cap (214). A piston rod (218) is slidably provided on the end cap (212), and a piston (219) is provided on the piston rod (218) to cooperate with the inner wall of the sampling tube (211). Both ends of the sealing cap (214) are provided with parts that slidably cooperate with the end cap (212). The sliding rods (213) are connected together. The ends of the two sliding rods (213) extending out of the end cap (212) are provided with a connecting seat (220). The connecting seat (220) and the end cap (212) are provided with a connecting assembly (223) to fix the two together. A return spring (222) is wound around the sliding rod (213) between the connecting seat (220) and the end cap (212). The piston rod (218) is provided with a push block (225) to release the connecting assembly (223). Each of the multiple end caps (212) spaced apart from each other is provided with a detachable suction pipe 1 (227), and the remaining multiple end caps (212) are provided with a detachable suction pipe 2 (228). The lifting seat (112) is provided with a control component (3) for the multiple suction pipes 1 (227) or suction pipe 2 (228) to perform individual or simultaneous suction.

2. The sampling device for detecting gaseous pollutants according to claim 1, characterized in that: The control component (3) includes a control cylinder (311) disposed on the lifting seat (112). A rotating shaft (312) is rotatably inserted through any end of the control cylinder (311), and a sealing seat (313) that cooperates with the inner wall of the control cylinder (311) is provided on the rotating shaft (312). Under the action of the sealing seat (313), the control cylinder (311) is divided into an independent suction cylinder (314) and a suction cylinder (315). The other ends of multiple suction pipes (227) are connected to the suction cylinder (314) and communicate with its interior. The other ends of multiple suction pipes (228) are connected to the suction cylinder (315) and communicate with its interior. A suction pipe three (316) is provided on the control cylinder (311) corresponding to the sealing seat (313), and the sealing seat (313) is provided with through holes one (317), through holes two (318) and through holes three (319) connected to the suction pipe three (316) at equal intervals along its circumference. The through hole one (317) is a T-shaped structure that is connected to the suction cylinder one (314) and the suction cylinder two (315) at both ends respectively. The through holes two (318) and through holes three (319) are L-shaped structures arranged in opposite directions that are connected to the suction cylinder one (314) and the suction cylinder two (315) respectively. The lifting seat (112) is provided with an adjustment component (4) for controlling the rotation of the rotating shaft one (312).

3. The sampling device for detecting gaseous pollutants according to claim 2, characterized in that: The adjustment assembly (4) includes a worm gear (411) disposed on the outer end of the rotating shaft (312). Fixed seats (412) are provided on the lifting seats (112) corresponding to both ends of the worm gear (411). A worm (413) meshing with the worm gear (411) is disposed on both fixed seats (412). The end of the worm (413) extending out of either fixed seat (412) is connected to the output shaft of the motor (414). A detection assembly (5) for controlling the rotation angle of the worm gear (411) is provided on the lifting seat (112).

4. A sampling device for detecting gaseous pollutants according to claim 3, characterized in that: The detection component (5) includes an L-shaped support rod (511) set on the lifting seat (112). The support rod (511) is provided with a disc (512) corresponding to the worm gear (411). Three detection blocks (513) are equidistantly arranged on the outer end face of the worm gear (411) along its circumferential direction. A U-shaped frame (514) is provided on the disc (512) corresponding to any one of the detection blocks (513). A proximity switch (515) is provided on the U-shaped frame (514) to cooperate with the detection block (513).

5. A sampling device for detecting gaseous pollutants according to claim 1, characterized in that: The base (1) has three positioning seats (125) equidistantly arranged along its circumference on its outer side surface. A hinge seat (126) is provided on the base (1) in the middle between each pair of positioning seats (125). A detachable tripod (7) is provided on all three hinge seats (126).

6. A sampling device for detecting gaseous pollutants according to any one of claims 1-5, characterized in that: The bottom surface of the connecting cylinder (111) is detachably provided with a bottom cover (115) that rotates with the base (1). A large gear (117) is sleeved on the outer side of the bottom cover (115), and a small gear (119) that meshes with the large gear (117) is rotatably provided on the base (1).

7. A sampling device for detecting gaseous pollutants according to claim 6, characterized in that: Both ends of the bottom cover (115) are provided with electric push rods (116), and the movable ends of the two electric push rods (116) are respectively connected to the bottom surface of the lifting seat (112).

Images