Passive sampling device

Abstract

The invention provides a passive sampling device which is characterized in that a plurality of fixing ring pipes are sequentially arranged in a collecting pipe body in the axial direction of the collecting pipe body, and an adsorption slide glass is located in the collecting pipe body and arranged between any two adjacent fixing ring pipes or arranged on the side, facing a collecting pipe opening, of any fixing ring pipe. The adsorption slide glass is arranged on one side, opposite to the collection pipe opening, of any fixed ring pipe, so that the relative position of the adsorption slide glass in the collection pipe body can be adaptively adjusted based on the concentration condition of the target gas in the monitoring environment and the standard sampling time before the target gas in the monitoring environment is sampled; further, the diffusion path of the target gas in the collecting pipe body is changed, and the monitoring result of the target gas in the monitoring environment is prevented from being influenced.

Description

Technical Field

[0001] The present application belongs to the technical field of atmospheric environment monitoring, and more specifically, to a passive sampling device. Background Art

[0002] At present, in atmospheric environment monitoring, passive sampling technology mainly uses the adsorption carrier inside the sampling device to capture the target gas, so that the target gas concentration inside the sampling device forms a gradient difference with the target gas concentration in the monitoring environment, and then realizes the continuous collection of the target gas in the monitoring environment based on the gas diffusion principle.

[0003] However, in existing passive sampling devices, the adsorption carrier is usually encapsulated and fixed inside the sampling device, so that the gas diffusion path in the sampling device is relatively fixed, resulting in the inability to adaptively adjust the different concentrations of the target gas in the monitoring environment. It is further inconvenient to adaptively adjust the sampling device's collection rate of the target gas based on the standard sampling time, which ultimately affects the monitoring results of the target gas in the monitoring environment. Summary of the invention

[0004] The purpose of the present application is to provide a passive sampling device, which aims to solve the problem that the gas diffusion path in the current passive sampling device is relatively fixed, resulting in the inability to adaptively adjust the different concentrations of the target gas in the monitoring environment, and thus it is inconvenient to adaptively adjust the sampling rate of the sampling device for the target gas based on the standard sampling time, which ultimately affects the monitoring results of the target gas in the monitoring environment.

[0005] To achieve the above-mentioned purpose, the technical solution adopted in the present application is to provide a passive sampling device, including a collection tube body, a filter cover body, a sealing cover body, an adsorption carrier and multiple fixed ring tubes. One end of the collection tube body is provided with a collection tube opening connected to the outside world. The filter cover body is covered at the collection tube opening of the collection tube body, and is provided with a filter cover opening connected to the collection tube opening. The sealing cover body is used to synchronously open the collection tube opening and the filter cover opening, or to synchronously close the collection tube opening and the filter cover opening. Multiple fixed ring tubes are sequentially arranged inside the collection tube body along the axial direction of the collection tube body. The adsorption carrier is located inside the collection tube body and is arranged between any two adjacent fixed ring tubes, or is arranged on the side of any one of the fixed ring tubes facing the collection tube opening, or is arranged on the side of any one of the fixed ring tubes facing away from the collection tube opening.

[0006] In one of the embodiments, the inner wall of the collection tube body is provided with a plurality of guide prisms along the axial direction of the collection tube body, and the plurality of guide prisms are equidistantly distributed in the circumferential direction along the collection tube body in sequence, and the edge of the adsorption carrier is provided with a plurality of guide notches, and the plurality of guide notches are respectively and one-to-one corresponding to and connected to each guide prism along the axial direction of the collection tube body, and the outer wall of the fixed ring tube is provided with a plurality of guide grooves, and the plurality of guide grooves are respectively and one-to-one corresponding to and connected to each guide prism along the axial direction of the collection tube body.

[0007] In one embodiment, the adsorption carrier includes an adsorption area and a fixed area arranged around the outer periphery of the adsorption area, the adsorption area avoids each fixed ring tube along the axial direction of the collection tube body, the fixed area is relative to each fixed ring tube along the axial direction of the collection tube body, the adsorption area has an adsorption coating, and the fixed area is provided with a plurality of guide notches.

[0008] In one of the embodiments, a first flange is provided on the inner wall of the filter cover body, and the first flange abuts against one end portion of the collection tube body provided with a collection tube opening. A plastic filter membrane and a metal screen are also provided inside the filter cover body. The plastic filter membrane and the metal screen are fixed in sequence along the axial direction of the collection tube body on the side of the first flange facing away from the collection tube opening, and the plastic filter membrane is located on the side adjacent to the collection tube opening, and the metal screen is located on the side away from the collection tube opening.

[0009] In one embodiment, a second flange is provided on the inner wall of the filter cover body, and the first flange and the second flange are spaced relative to each other along the axial direction of the collection tube body to cooperate to form an annular groove, and the plastic filter membrane and the metal screen are clamped and fixed in the annular groove.

[0010] In one embodiment, a first thread is provided on the outer wall of one end of the collecting tube body adjacent to the collecting tube mouth, a second thread adapted to the first thread to form a threaded connection is provided on the inner wall of one end of the filter cover body adjacent to the collecting tube body, and friction stripes are also provided on the outer wall of one end of the filter cover body adjacent to the collecting tube body.

[0011] In one embodiment, the minimum diameter of the filter cover is 20 mm, the metal screen is a stainless steel screen with a pore size less than 35 meshes, and the plastic filter membrane is a polytetrafluoroethylene filter membrane with a pore size of 5 um.

[0012] In one embodiment, the collection tube body, the filter cover body, the sealing cover body and each fixed ring tube are all made of polyethylene, and the adsorption carrier is a fiber filter paper with an adsorption coating.

[0013] In one of the embodiments, it also includes a protective outer cover and a protective screen. The protective outer cover has a cavity structure inside. The bottom of the cavity structure has an opening connected to the outside world. The top of the cavity structure is provided with an adhesive layer. A movable cover of the protective screen is provided on the opening. Multiple collection tube bodies and corresponding filter cover bodies are all located in the cavity structure. The ends of the multiple collection tube bodies facing away from the collection tube openings are respectively adhered and fixed to the adhesive layer.

[0014] In one of the embodiments, it also includes a positioning module and a terminal module. The positioning module is located in the cavity structure and is adhered and fixed on the adhesive layer. The terminal module is communicatively connected to the positioning module and is used to receive real-time positioning information sent by the positioning module, and to issue a reminder alarm when the real-time positioning information sent by the positioning module leaves a preset range.

[0015] The beneficial effect of the sealing structure provided by the present application is that, compared with the prior art, the above-mentioned passive sampling device includes a collection tube body, a filter cover body, a sealing cover body, an adsorption carrier and a plurality of fixed ring tubes, wherein one end portion of the collection tube body is provided with a collection tube opening connected to the outside, the filter cover body is arranged at the collection tube opening of the collection tube body, and is provided with a filter cover opening connected to the collection tube opening, the sealing cover body is used to synchronously open the collection tube opening and the filter cover opening, or to synchronously close the collection tube opening and the filter cover opening, a plurality of fixed ring tubes are sequentially arranged inside the collection tube body along the axial direction of the collection tube body, the adsorption carrier is located inside the collection tube body, and is arranged between any two adjacent fixed ring tubes, or is arranged on the side of any one of the fixed ring tubes facing the collection tube opening, or is arranged on any one of the fixed ring tubes. On the side facing away from the collection tube mouth, before sampling the target gas in the monitoring environment, the relative position of the adsorption carrier inside the collection tube body can be adaptively adjusted based on the concentration of the target gas in the monitoring environment and the standard sampling time, thereby changing the diffusion path of the target gas inside the collection tube body. For example, when the concentration of the target gas in the monitoring environment is high, a longer diffusion path is correspondingly set to reduce the adsorption rate of the adsorption carrier, thereby preventing the adsorption carrier from being saturated too early at the standard sampling time. When the concentration of the target gas in the monitoring environment is low, a shorter diffusion path is correspondingly set to increase the adsorption rate of the adsorption carrier, so that the adsorption carrier can collect a relatively suitable content of the target gas within the standard sampling time, thereby avoiding affecting the monitoring results of the target gas in the monitoring environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A perspective structural diagram of a passive sampling device provided in Embodiment 1 of the present application;

[0018] Figure 2 for Figure 1 A schematic diagram of the main structure of the collection tube body and related structures in the passive sampling device shown;

[0019] Figure 3 for Figure 2 A schematic cross-sectional structure diagram of a collection tube body and related structures shown;

[0020] Figure 4 for Figure 1 A schematic diagram of the structure of the collection tube in the passive sampling device as viewed from above;

[0021] Figure 5 for Figure 1 A schematic diagram of the structure of the adsorption slide in the passive sampling device as viewed from above;

[0022] Figure 6 for Figure 1 A schematic diagram of the structure of the fixed ring tube in the passive sampling device shown in FIG.

[0023] In the figure: 10, passive sampling device; 100, collection tube body; 101, collection tube mouth; 102, guide prism; 200, filter cover body; 201, filter cover mouth; 202, first flange; 203, second flange; 204, annular groove; 205, friction stripes; 210, plastic filter membrane; 220, metal screen; 300, sealing cover body; 400, adsorption carrier; 410, adsorption area; 420, fixing area; 422, guide notch; 500, fixing ring tube; 502, guide groove; 600, protective cover; 601, cavity structure; 602, opening; 610, adhesion layer; 700, protective screen. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0026] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0028] Please also read Figure 1 , Figure 2 and Figure 3 , the passive sampling device 10 provided in an embodiment of the present application is now described. The above-mentioned passive sampling device 10 includes a collection tube body 100, a filter cover body 200, a sealing cover body 300, an adsorption carrier 400 and a plurality of fixed ring tubes 500, wherein one end of the collection tube body 100 is coaxially provided with a collection tube port 101 connected to the outside for collecting target gas in the monitoring environment, the filter cover body 200 is covered at the collection tube port 101 of the collection tube body 100, and is coaxially provided with a filter cover port 201 connected to the collection tube port 101, so that the target gas in the monitoring environment passes through the filter cover port 201 and the collection tube port 101 in turn and then enters the interior of the collection tube body 100 during the collection process, and the collection operation is performed on the target gas. Before and after the collection operation is completed, the sealing cover body 300 covers the filter cover body 200 to synchronously close the collection tube port 101 and the filter cover port 201. When the target gas is collected, the sealing cover body 300 is separated from the filter cover body 200 to synchronously open the collection tube port 101 and the filter cover port 201. A plurality of fixed ring tubes 500 are stacked in sequence along the axial direction of the collection tube body 100 inside the collection tube body 100. The corresponding adsorption carrier 400 is located inside the collection tube body 100 and is fixedly arranged between any two adjacent fixed ring tubes 500, or fixedly arranged on the side of any one of the fixed ring tubes 500 facing the collection tube port 101, or fixedly arranged on the side of any one of the fixed ring tubes 500 facing away from the collection tube port 101.

[0029] It should be noted that, in the present embodiment, the closer the above-mentioned adsorption carrier 400 is to the collection tube opening 101 along the axial direction of the collection tube body 100, the shorter the diffusion path of the target gas in the collection tube body 100, and the faster the adsorption speed of the adsorption carrier 400 is. When the adsorption carrier 400 is fixedly arranged on the side of any one of the fixed ring tubes 500 facing the collection tube opening 101, the diffusion path of the target gas in the collection tube body 100 reaches a minimum value, and the adsorption speed of the adsorption carrier 400 reaches a maximum value. Conversely, the farther the above-mentioned adsorption carrier 400 is from the collection tube opening 101 along the axial direction of the collection tube body 100, the longer the diffusion path of the target gas in the collection tube body 100 is, and the slower the adsorption speed of the adsorption carrier 400 is. When the adsorption carrier 400 is fixedly arranged on the side of any one of the fixed ring tubes 500 facing away from the collection tube opening 101, the diffusion path of the target gas in the collection tube body 100 reaches a maximum value, and the adsorption speed of the adsorption carrier 400 reaches a minimum value. Please refer to Figure 2From the perspective of perspective, in the present embodiment, the adsorption carrier 400 is fixedly arranged on the side of any one of the fixed ring tubes 500 facing away from the collection tube opening 101, that is, the test adsorption carrier 400 is fixedly arranged between the bottom end of the collection tube body 100 and any one of the fixed ring tubes 500. Correspondingly, at this time, the diffusion path of the target gas in the collection tube body 100 reaches a maximum value, that is, the adsorption speed of the adsorption carrier 400 reaches a minimum value.

[0030] The beneficial effect of the passive sampling device 10 provided in the present application is that, compared with the prior art, the adsorption carrier 400 in the above-mentioned passive sampling device 10 is located inside the collection tube body 100, and is arranged between any two adjacent fixed ring tubes 500, or is arranged on the side of any fixed ring tube 500 facing the collection tube mouth 101, or is arranged on the side of any fixed ring tube 500 facing away from the collection tube mouth 101. In this way, before sampling the target gas in the monitoring environment, the adsorption carrier 400 can be adaptively adjusted based on the concentration of the target gas in the monitoring environment and the standard sampling time. The relative position inside the tube body 100 changes the diffusion path of the target gas inside the collection tube body 100. For example, when the concentration of the target gas in the monitoring environment is high, a longer diffusion path is correspondingly set to reduce the adsorption rate of the adsorption carrier 400, thereby preventing the adsorption carrier 400 from being saturated too early at the standard sampling time. When the concentration of the target gas in the monitoring environment is low, a shorter diffusion path is correspondingly set to increase the adsorption rate of the adsorption carrier 400, so that the adsorption carrier 400 can collect a relatively suitable content of the target gas within the standard sampling time, thereby avoiding affecting the monitoring results of the target gas in the monitoring environment.

[0031] Please also read Figure 3 , Figure 4 , Figure 5 and Figure 6 In the present embodiment, the inner wall of the collection tube body 100 is provided with a plurality of guide prisms 102 along the axial direction of the collection tube body 100, and the guide prisms 102 are equidistantly distributed in sequence along the axial direction of the collection tube body 100. The edge of the adsorption carrier 400 is provided with a plurality of guide notches 422, and the plurality of guide notches 422 are respectively and one by one correspondingly connected to each guide prism 102 along the axial direction of the collection tube body 100. The outer wall of the fixed ring tube 500 is provided with a plurality of guide grooves 502, and the plurality of guide grooves 502 are respectively and one by one correspondingly connected to each guide prism 102 along the axial direction of the collection tube body 100.

[0032] It should be noted that, in the present embodiment, the guiding connection relationship between the above-mentioned guiding prism 102 and the corresponding guiding notch 422 and the corresponding guiding groove 502 can facilitate the rapid disassembly and assembly of the adsorption carrier 400 and each fixed ring tube 500 in the collection tube body 100. In addition, after the adsorption carrier 400 and each fixed ring tube 500 are arranged in the collection tube body 100, a limiting effect can also be provided for the adsorption carrier 400 and each fixed ring tube 500, thereby improving the structural stability of the passive sampling device 10.

[0033] Furthermore, in the present embodiment, the adsorption carrier 400 includes an adsorption region 410 and a fixed region 420 arranged in a ring around the adsorption region 410, the adsorption region 410 avoids each fixed ring tube 500 along the axial direction of the collection tube body 100, and the fixed region 420 is relative to each fixed ring tube 500 along the axial direction of the collection tube body 100, that is, the cross-sectional area of ​​the adsorption region 410 is adapted to the inner ring cross-sectional area of ​​the fixed ring tube 500, and the adsorption region 410 has an adsorption coating, and the fixed region 420 is provided with a plurality of guide notches 422 along the circumferential direction.

[0034] Further, in this embodiment, the inner wall of the filter cover body 200 is coaxially provided with a first flange 202, and the first flange 202 abuts against one end of the collection tube body 100 provided with the collection nozzle 101 along the axial direction of the collection tube body 100, and then abuts against the side of the fixed area 420 of the corresponding adjacent adsorption carrier 400 facing the collection nozzle 101 along the axial direction of the collection tube body 100, or abuts against the side of a corresponding adjacent fixed ring tube 500 facing the collection nozzle 101 along the axial direction of the collection tube body 100, and the filter cover A plastic filter membrane 210 and a metal screen 220 are also provided inside the body 200, wherein the plastic filter membrane 210 and the metal screen 220 are fixed in sequence along the axial direction of the collection tube body 100 on the side of the first flange 202 facing away from the collection tube opening 101, the plastic filter membrane 210 is located on the side adjacent to the collection tube opening 101, and the metal screen 220 is located on the side away from the collection tube opening 101, and the plastic filter membrane 210 and the metal screen 220 are used to filter out other impurities in the monitoring environment and reduce the gas flow rate at the filter cover 201.

[0035] Furthermore, in this embodiment, the inner wall of the filter cover body 200 is provided with a second flange 203, and the first flange 202 and the second flange 203 are arranged relatively spaced apart along the axial direction of the collection tube body 100, so that an annular groove 204 is formed between the first flange 202 and the second flange 203, and the plastic filter membrane 210 and the metal screen 220 are clamped and fixed in the annular groove 204.

[0036] Furthermore, in the present embodiment, a first thread (not shown in the figure) is provided on the outer wall of one end of the collection tube body 100 adjacent to the collection tube mouth 101, a second thread (not shown in the figure) adapted to the first thread to form a threaded connection is provided on the inner wall of one end of the filter cover body 200 adjacent to the collection tube body 100, and a friction stripe 205 is also provided on the outer wall of one end of the filter cover body 200 adjacent to the collection tube body 100 to facilitate twisting of the filter cover body 200 through the friction stripe 205.

[0037] Furthermore, in this embodiment, the minimum diameter of the above-mentioned filter cover 201 is 20 mm, the metal screen 220 is a stainless steel screen with a pore size less than 35 mesh, the plastic filter membrane 210 is a polytetrafluoroethylene filter membrane with a pore size of 5 um, the collection tube body 100, the filter cover body 200, the sealing cover body 300 and each fixed ring tube 500 are all polyethylene parts, and the adsorption carrier 400 is a fiber filter paper with an adsorption coating.

[0038] See also Figure 1 And Figure 1 Taking the middle perspective as an example, in this embodiment, the above-mentioned passive sampling device 10 further includes a protective cover 600 and a protective screen 700, wherein the protective cover 600 has a cavity structure 601 inside, the bottom of the cavity structure 601 is provided with an opening 602 communicating with the outside, the top of the cavity structure 601 is provided with an adhesive layer 610, and the protective screen 700 is detachably covered on the opening 602. In this way, after the corresponding sealing covers 300 of the plurality of collection tube bodies 100 are removed, the plurality of collection tube bodies 100 can be arranged in the cavity structure 601 (corresponding to each collection tube body 100). The filter cover bodies 200 connected to the collecting tube body 100 are also located in the cavity structure 601), and the end of each collecting tube body 100 facing away from the collecting tube mouth 101 is adhered and fixed on the adhesive layer 610, and then the protective screen 700 is covered and the protective outer cover 600 is hung at an appropriate position in the monitoring environment, so that each collecting tube body 100 is arranged upside down, and the protective outer cover 600 and the protective screen 700 cooperate to cover each collecting tube body 100, which can better prevent external dust and other debris from invading the interior of the collecting tube body 100 and interfering with the final detection result.

[0039] Specifically, in the present embodiment, the protective screen 700 is snap-fitted onto the opening 602 ; in some other embodiments, a plurality of supporting protrusions (not shown) are provided on the outer wall of the protective cover 600 adjacent to the opening 602 , and the protective screen 700 is supported on the plurality of supporting protrusions and covers the opening 602 .

[0040] Furthermore, in the present embodiment, the above-mentioned passive sampling device 10 also includes a positioning module (not shown in the figure) and a terminal module (not shown in the figure). The positioning module is located in the cavity structure 601, adhered and fixed on the adhesion layer 610 and communicatively connected to the terminal module. The terminal module is used to receive real-time positioning information issued by the positioning module, and to issue a reminder alarm when the real-time positioning information issued by the positioning module leaves a preset range. In some other embodiments, the positioning modules are fixedly arranged one by one on the outer wall of each collection tube body 100 of the cavity structure 601.

[0041] It should be noted that the theoretical sampling rate of the passive sampling device 10 provided in the present application can be calculated based on Fick's first law (1):

[0042] Q = 60 × D × A / L (1)

[0043] Where Q is the sampling rate (mL / min), D is the diffusion coefficient of the target gas in air (cm 2 / s), A is the diffusion cross-sectional area (cm 2 ), L is the diffusion length (cm). Specifically, in the present application, the diffusion cross-sectional area A is the inner ring cross-sectional area of ​​the fixed ring tube 500, and the diffusion length L is the distance between the adsorption carrier 400 and the plastic filter membrane 210 along the axial direction of the collection tube body 100. The diffusion length L can be calculated based on formula (2):

[0044] L=n×L1+L2(2)

[0045] Wherein, n is the number of fixed ring tubes 500 between the adsorption carrier 400 and the plastic filter membrane 210, L1 is the axial length (cm) of a fixed ring tube 500, and L2 is the distance (cm) between the plastic filter membrane 210 and the collection tube mouth 101 along the axial direction of the collection tube body 100.

[0046] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A passive sampling device, characterized in that: It includes a collection tube body, a filter cover body, a sealing cover body, an adsorption carrier and multiple fixed ring tubes. One end of the collection tube body is provided with a collection tube opening connected to the outside world. The filter cover body is covered at the collection tube opening of the collection tube body, and is provided with a filter cover opening connected to the collection tube opening. The sealing cover body is used to synchronously open the collection tube opening and the filter cover opening, or to synchronously close the collection tube opening and the filter cover opening. Multiple fixed ring tubes are sequentially arranged inside the collection tube body along the axial direction of the collection tube body. The adsorption carrier is located inside the collection tube body and is arranged between any two adjacent fixed ring tubes, or is arranged on the side of any one of the fixed ring tubes facing the collection tube opening, or is arranged on the side of any one of the fixed ring tubes facing away from the collection tube opening.

2. The passive sampling device according to claim 1, characterized in that: The inner wall of the collection tube body is provided with a plurality of guide prisms along the axial direction of the collection tube body, and the plurality of guide prisms are equidistantly distributed in the circumferential direction along the collection tube body in sequence; the edge of the adsorption carrier is provided with a plurality of guide notches, and the plurality of guide notches are respectively and one-to-one corresponding to guide and connect the guide prisms along the axial direction of the collection tube body; the outer wall of the fixed ring tube is provided with a plurality of guide grooves, and the plurality of guide grooves are respectively and one-to-one corresponding to guide and connect the guide prisms along the axial direction of the collection tube body.

3. The passive sampling device according to claim 2, characterized in that: The adsorption carrier includes an adsorption area and a fixed area arranged around the outer periphery of the adsorption area. The adsorption area avoids each of the fixed ring tubes along the axial direction of the collection tube body. The fixed area is relative to each of the fixed ring tubes along the axial direction of the collection tube body. The adsorption area has an adsorption coating, and the fixed area is provided with a plurality of guide notches.

4. The passive sampling device according to claim 1, characterized in that: The inner wall of the filter cover body is provided with a first flange, and the first flange abuts against an end portion of the collection tube body provided with the collection tube opening. A plastic filter membrane and a metal screen are also provided inside the filter cover body, and the plastic filter membrane and the metal screen are fixed in sequence along the axial direction of the collection tube body on a side of the first flange facing away from the collection tube opening, and the plastic filter membrane is located on a side adjacent to the collection tube opening, and the metal screen is located on a side away from the collection tube opening.

5. The passive sampling device according to claim 4, characterized in that: The inner wall of the filter cover body is provided with a second flange, and the first flange and the second flange are spaced relative to each other along the axial direction of the collection tube body to cooperate to form an annular groove, and the plastic filter membrane and the metal screen are clamped and fixed in the annular groove.

6. The passive sampling device according to claim 5, characterized in that: The outer wall of one end of the collection tube body adjacent to the collection tube mouth is provided with a first thread, the inner wall of one end of the filter cover body adjacent to the collection tube body is provided with a second thread adapted to the first thread to form a threaded connection, and the outer wall of one end of the filter cover body adjacent to the collection tube body is also provided with friction stripes.

7. The passive sampling device according to claim 6, characterized in that: The minimum diameter of the filter cover is 20 mm, the metal screen is a stainless steel screen with a pore size less than 35 meshes, and the plastic filter membrane is a polytetrafluoroethylene filter membrane with a pore size of 5 um.

8. The passive sampling device according to claim 1, characterized in that: The collection tube body, the filter cover body, the sealing cover body and each of the fixed ring tubes are all polyethylene parts, and the adsorption carrier is a fiber filter paper with an adsorption coating.

9. The passive sampling device according to any one of claims 1 to 8, characterized in that: It also includes a protective outer cover and a protective screen, wherein the protective outer cover has a cavity structure inside, the bottom of the cavity structure has an opening connected to the outside, the top of the cavity structure is provided with an adhesive layer, the protective screen movable cover is provided on the opening, the plurality of collection tube bodies and the corresponding filter cover bodies are all located in the cavity structure, and the ends of the plurality of collection tube bodies facing away from the collection tube openings are respectively adhered and fixed to the adhesive layer.

10. The passive sampling device according to claim 9, characterized in that: It also includes a positioning module and a terminal module. The positioning module is located in the cavity structure and is adhered and fixed on the adhesion layer. The terminal module is communicatively connected to the positioning module and is used to receive real-time positioning information sent by the positioning module, and to send out a reminder alarm when the real-time positioning information sent by the positioning module leaves a preset range.

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