Ion mobility detector

Abstract

The application discloses an ion migration detector and belongs to the technical field of substance detection. The ion migration detector comprises an ion migration tube and a filtering device. The ion migration tube is provided with a detection cavity, a circulating gas inlet and a circulating gas outlet. The circulating gas inlet and the circulating gas outlet are communicated with the detection cavity respectively. The filtering device comprises a filtering shell, a filter body, a pressing plate and a gas guide pipe. The inlet end of the filtering shell is communicated with the circulating gas outlet. The outlet end of the filtering shell is communicated with the circulating gas inlet. The pressing plate is arranged in the filtering shell. The internal space of the filtering shell is divided into a filtering cavity and a buffer cavity by the pressing plate. A plurality of through holes are arranged at intervals in the pressing plate. The buffer cavity is communicated with the filtering cavity through the through holes. The gas guide pipe and the filter body are located in the filtering cavity. The gas guide pipe penetrates through the pressing plate and is communicated with the buffer cavity. The inlet end of the filtering shell, the gas guide pipe, the buffer cavity, the filtering cavity and the outlet end of the filtering shell are communicated in sequence. In this way, the filtering effect and the detection accuracy are improved.

Description

Technical Field

[0001] This application belongs to the field of material detection technology, specifically relating to an ion migration detector. Background Technology

[0002] With social development, the demand for the detection of dangerous materials such as explosives and drugs in public places is increasing. Among them, ion migration detectors using ion migration spectroscopy technology can detect dangerous materials, thereby preventing dangerous materials from entering public places. Ion migration detectors have the advantages of being portable, fast, and sensitive, and are therefore widely used.

[0003] An ion migration detector includes an ion migration tube. The sample enters the ion migration tube and is ionized. The ionized ions collide with molecules in the circulating gas flow. Different types of ions reach the flange of the ion migration tube at different times. Therefore, the type of ion is determined based on the arrival time of the ions, thus achieving the purpose of detection.

[0004] The filtering device is an important component of the ion migration detector, but existing filtering devices suffer from complex structural design and poor filtering effect. Utility Model Content

[0005] The purpose of this application is to provide an ion migration detector that can at least solve the problems of complex structure and poor filtration effect of the filtering device in related technologies.

[0006] This application provides an ion migration detector, including:

[0007] An ion migration tube is provided with a detection chamber, a circulating gas inlet, and a circulating gas outlet, wherein the circulating gas inlet and the circulating gas outlet are respectively connected to the detection chamber;

[0008] A filtration device includes a filter housing, a filter body, a pressure plate, and a gas guide pipe. The inlet end of the filter housing is connected to the outlet of the circulating gas, and the outlet end of the filter housing is connected to the inlet of the circulating gas. The pressure plate is disposed inside the filter housing and divides the internal space of the filter housing into a filter chamber and a buffer chamber. The pressure plate is provided with multiple through holes at intervals, and the buffer chamber is connected to the filter chamber through the through holes.

[0009] The air guide tube and the filter body are both located inside the filter chamber, and the air guide tube passes through the pressure plate and communicates with the buffer chamber. The inlet end of the filter housing, the air guide tube, the buffer chamber, the filter chamber, and the outlet end of the filter housing are connected in sequence.

[0010] In this embodiment, a pressure plate and a gas guide tube are added to the internal structure of the ion migration detector's filtering device. The pressure plate divides the internal space of the filter housing into a filtering chamber and a buffer chamber. The filter body is housed in the filtering chamber to perform the filtering function. The gas guide tube leads from the inlet end of the filter housing to the buffer chamber, allowing the gas entering the filter housing to first enter the buffer chamber through the gas guide tube. The gas diffuses fully in the buffer chamber and then seeps into the filtering chamber through multiple through holes on the pressure plate. This ensures that the gas and the filter body are in full contact, which is beneficial for the filter body to fully filter the gas, improves the filtering effect and the cleanliness of the gas, and thus improves the detection effect of the ion migration tube on the sample and enhances the detection accuracy.

[0011] Moreover, apart from the filter housing and filter body, the pressure plate and air guide tube are all necessary components. The filter device has fewer components, which helps to simplify the structure of the filter device and avoid problems such as cumbersome structure and complex design. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the working principle of the ion migration detector disclosed in the embodiments of this application;

[0013] Figure 2 This is a top view of the ion migration detector disclosed in the embodiments of this application;

[0014] Figure 3 This is a schematic diagram of the structure of the ion migration detector disclosed in the embodiments of this application;

[0015] Figure 4 This is a schematic diagram of the sampling air pump disclosed in the embodiments of this application;

[0016] Figure 5 This is an exploded view of the sampling air pump disclosed in the embodiments of this application;

[0017] Figure 6 This is a cross-sectional view of the sampling air pump disclosed in the embodiments of this application;

[0018] Figure 7 This is a schematic diagram of the calibration device disclosed in the embodiments of this application;

[0019] Figure 8 This is an exploded view of the calibration device disclosed in the embodiments of this application;

[0020] Figure 9 This is a cross-sectional view of the calibration device disclosed in the embodiments of this application;

[0021] Figure 10 This is a schematic diagram of the structure of a filtration device disclosed in an embodiment of this application;

[0022] Figure 11 This is an exploded view of a filtering device disclosed in an embodiment of this application;

[0023] Figure 12 This is a cross-sectional view of a filtering device disclosed in an embodiment of this application;

[0024] Figure 13 This is a schematic diagram of the structure of a filtration device disclosed in another embodiment of this application;

[0025] Figure 14 This is an exploded view of a filtering device disclosed in another embodiment of this application;

[0026] Figure 15 This is a cross-sectional view of a filtering device disclosed in another embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 100 - Ion migration tube, 101 - Detection chamber, 101a - Ionization region, 101b - Migration region, 102 - Detection inlet, 103 - Calibration outlet, 104 - Circulating gas inlet, 105 - Circulating gas outlet.

[0029] 110 - Thermal desorption apparatus, 110a - Calibration inlet

[0030] 200 - Sampling air pump; 210 - Air pump body; 211 - Air inlet end; 212 - Air outlet end; 220 - Air pump adapter; 220a - Air inlet channel; 220b - Air outlet channel; 221 - First adapter; 222 - Second adapter; 230 - First air inlet connector; 240 - First air outlet connector; 250 - Fourth seal.

[0031] 300-Calibration device, 310-Calibration cavity, 310a-Calibration cavity, 310b-Third mounting port, 320-Calibration object, 330-Third sealing cover, 331-Second cover, 332-Second boss, 333-Hook, 340-Third sealing element, 350-Temperature sensing element, 360-Heating element, 370-Insulation layer, 380-Second air inlet connector, 390-Second air outlet connector.

[0032] 400 - Selector control valve, 410 - First air inlet, 420 - First air outlet, 430 - Second air outlet.

[0033] 500-circulating air pump

[0034] 600-Filter device, 600a-Filter housing, 610-Main housing, 611-Filter chamber, 612-First mounting port, 613-Second mounting port, 620-Filter body, 630-First sealing cover, 631-First cover, 632-First boss, 632a-Buffer chamber, 640-Second sealing cover, 650-Inlet adapter, 651-Adapter block, 660-Outlet adapter, 670-Pressure plate, 671-Through hole, 672-Opening, 680-Air guide pipe, 691-First dustproof screen, 692-Second dustproof screen, 693-First seal, 694-Second seal.

[0035] 710 - Flow detection element, 720 - Humidity and temperature detection element

[0036] 800-Support base, 810-Shock absorber, 820-High voltage plate, 830-Control board, 840-Data acquisition module

[0037] 900 - Fasteners. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0039] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0040] The ion migration detector provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0041] Please refer to Figures 1-15The ion migration detector disclosed in this application is used to detect solid or liquid hazardous materials such as explosives and drugs. The ion migration detector includes an ion migration tube 100 and a filter device 600. Under the action of an electric field, the sample entering the ion migration tube 100 is ionized, and the ion migration tube 100 separates and detects substances based on the migration rate of the ions; the filter device 600 is used to filter the gas in the circulating gas path.

[0042] Specifically, refer to Figure 1 As shown, the ion migration tube 100 is provided with a detection chamber 101, a circulating gas inlet 104, and a circulating gas outlet 105, which are respectively connected to the detection chamber 101. The inlet end of the filter device 600 is connected to the circulating gas outlet 105, and the outlet end of the filter device 600 is connected to the circulating gas inlet 104. That is to say, the gas circulating in the circulating gas path formed by the ion migration tube 100 is filtered by the filter device 600, which helps to improve the cleanliness of the gas and makes it easier for the ion migration tube 100 to accurately detect the sample.

[0043] Optionally, the ion migration detector also includes a high-voltage plate 820 located on one side of the ion migration tube 100. The high-voltage plate 820 is used to provide an electric field to ionize the gas inside the ion migration tube 100.

[0044] refer to Figures 10-15 As shown, the filtration device 600 includes a filter housing 600a, a filter body 620, a pressure plate 670, and a gas guide pipe 680. The filter housing 600a is used to install the filter body 620. The filter body 620 can be a molecular sieve or activated carbon or other substances that can perform filtration. The inlet end of the filter housing 600a is connected to the circulating gas outlet 105, and the outlet end of the filter housing 600a is connected to the circulating gas inlet 104.

[0045] A pressure plate 670 is disposed within the filter housing 600a, dividing the internal space of the filter housing 600a into a filter chamber 611 and a buffer chamber 632a. Furthermore, the pressure plate 670 is provided with multiple through holes 671 at intervals, and the buffer chamber 632a communicates with the filter chamber 611 through the through holes 671. Optionally, the pressure plate 670 can be a square plate, a circular plate, etc. This application embodiment does not limit the specific structure of the pressure plate 670. In short, the edge of the pressure plate 670 is connected to the inner wall surface of the filter housing 600a, specifically through welding, bonding, or other methods; the through holes 671 can be square holes, circular holes, etc., and all through holes 671 have the same shape and equal area.

[0046] Both the air guide pipe 680 and the filter body 620 are located within the filter chamber 611, and the air guide pipe 680 passes through the pressure plate 670 and communicates with the buffer chamber 632a. The inlet end of the filter housing 600a, the air guide pipe 680, the buffer chamber 632a, the filter chamber 611, and the outlet end of the filter housing 600a are sequentially connected. Optionally, both the inlet end and the outlet end of the filter housing 600a are located at one end of the filter housing 600a, and the buffer chamber 632a is located at the other end of the filter housing 600a. The axial direction of the air guide pipe 680 can be the same as the direction of extension of the filter housing 600a to shorten the length of the air guide pipe 680. Figure 11 and Figure 14 As shown, the pressure plate 670 is also provided with an opening 672 for the air guide tube 680 to pass through, so as to prevent the pressure plate 670 from blocking the air guide tube 680 from extending into the buffer cavity 632a.

[0047] In this embodiment, a pressure plate 670 and a gas guide pipe 680 are added to the internal structure of the ion migration detector's filtering device 600. The pressure plate 670 divides the internal space of the filter housing 600a into a filtering chamber 611 and a buffer chamber 632a. The filter body 620 is housed in the filtering chamber 611 to perform a filtering function. The gas guide pipe 680 leads from the inlet end of the filter housing 600a to the buffer chamber 632a, so that the gas entering the filter housing 600a first enters the buffer chamber 632a through the gas guide pipe 680. The gas diffuses fully in the buffer chamber 632a and then seeps into the filtering chamber 611 through the multiple through holes 671 on the pressure plate 670. This ensures that the gas and the filter body 620 are in full contact, which is beneficial for the filter body 620 to fully filter the gas, improves the filtering effect and the cleanliness of the gas, and thus improves the detection effect of the ion migration tube 100 on the sample and improves the detection accuracy.

[0048] Moreover, apart from the filter housing 600a and the filter body 620, the pressure plate 670 and the air guide pipe 680 are essential components. The filter device 600 has fewer components, which helps to simplify the structure of the filter device 600 and avoid problems such as cumbersome structure and complex design of the filter device 600.

[0049] In an optional embodiment, the filter housing 600a includes a main housing portion 610 and a first sealing cover 630. The main housing portion 610 is provided with a communicating filter cavity 611 and a first mounting port 612. The filter cavity 611 is used to accommodate the filter body 620. The filter body 620 can enter the filter cavity 611 through the first mounting port 612. Optionally, the first mounting port 612 is opened at the end of the main housing portion 610. Of course, the first mounting port 612 can also be opened on the side wall of the main housing portion 610.

[0050] Optionally, the first mounting port 612 and the first sealing cover 630 can be square, circular, or other structures. This application does not limit the structure of the first mounting port 612 and the first sealing cover 630, as long as the first sealing cover 630 can close the first mounting port 612.

[0051] The first sealing cap 630 is detachably disposed at the first mounting port 612. Optionally, refer to Figures 10-12 As shown, the first sealing cover 630 and the filter housing 600a can be connected by fasteners 900 such as bolts and screws, or, as shown in the reference... Figures 13-15 As shown, the first sealing cover 630 and the filter housing 600a can be connected by threads. That is, the circumferential surface of the first sealing cover 630 is provided with a first external thread, and the first mounting port 612 is provided with a first internal thread, with the first external thread and the first internal thread engaging. Of course, the first sealing cover 630 and the filter housing 600a can also be connected by other detachable methods.

[0052] In this embodiment, after the filter body 620 has been used for a period of time, the user can remove the first sealing cover 630 as needed, open the first installation port 612, remove the filter body 620 and replace it with a new filter body 620, so as to ensure that the filter device 600 continuously filters the gas in the circulating gas path.

[0053] In the present application, the filter device 600 further includes a second sealing cover 640, an air inlet adapter 650, and an air outlet adapter 660. The second sealing cover 640 is used to install the air inlet adapter 650 and the air outlet adapter 660. The main housing 610 is also provided with a second mounting port 613, which communicates with the filter chamber 611. The air inlet adapter 650 and the air outlet adapter 660 are respectively disposed on the second sealing cover 640, and the air inlet adapter 650 and the air outlet adapter 660 are respectively communicated with the filter chamber 611.

[0054] Optionally, the second mounting port 613 can be opened at the end of the main housing portion 610, with the first mounting port 612 opposite to the second mounting port 613. Of course, the second mounting port 613 can also be opened on the side wall of the main housing portion 610. The second mounting port 613 and the second sealing cover 640 can be circular, square, or other structures. The embodiments of this application do not limit the specific structure of the second mounting port 613 and the second sealing cover 640, as long as the second sealing cover 640 can close the second mounting port 613.

[0055] The second sealing cover 640 is detachably disposed at the second mounting port 613, optionally, as shown in the reference. Figures 10-12 As shown, the second sealing cover 640 and the filter housing 600a can be connected by fasteners 900 such as bolts and screws, or, as shown in the reference... Figures 13-15As shown, the second sealing cover 640 and the filter housing 600a can be connected by threads. That is, the second sealing cover 640 has a second external thread on its circumferential surface and a second internal thread at the second mounting port 613. The second external thread and the second internal thread cooperate with each other. Of course, the second sealing cover 640 and the filter housing 600a can also be connected by other detachable methods.

[0056] Thus, the first end of the air guide tube 680 is connected to the air intake adapter 650, and the second end of the air guide tube 680 is connected to the buffer chamber 632a, thereby connecting the air intake adapter 650 to the buffer chamber 632a through the air guide tube 680, and the air outlet adapter 660 to the filter chamber 611.

[0057] In this embodiment, the second sealing cover 640 is detachable, and the user can disassemble the second sealing cover 640 as needed to facilitate the maintenance and replacement of the air intake adapter 650 and the air exhaust adapter 660.

[0058] Optionally, the filter device 600 further includes an adapter block 651, which is disposed between the first end of the air guide pipe 680 and the air inlet adapter 650. The air inlet adapter 650 is connected to the air guide pipe 680 through the adapter block 651. Further optionally, the inlet end of the adapter block 651 is inserted into the air inlet adapter 650, and the outlet end of the adapter block 651 is inserted into the air guide pipe 680.

[0059] Of course, in other embodiments, the second sealing cover 640 and the filter housing 600a can also be connected by non-removable means such as welding.

[0060] In a further embodiment, the filter device 600 further includes a first seal 693, which is disposed between the first sealing cover 630 and the main housing portion 610 of the filter housing 600a to seal the gap between the first sealing cover 630 and the main housing portion 610. Optionally, the first seal 693 is located between the circumferential surface of the first sealing cover 630 and the inner wall surface of the main housing portion 610 for radial sealing. Further optionally, the first seal 693 can be a sealing ring made of rubber, and the sealing ring is fitted over the outside of the first sealing cover 630.

[0061] In this embodiment, the filter device 600 is equipped with a first sealing element 693, which seals the gap between the first sealing cover 630 and the main housing 610, thereby improving the sealing performance and preventing foreign objects from entering the filter chamber 611.

[0062] Of course, in other embodiments, the filter device 600 may not have the first seal 693, and the first sealing cover 630 and the main housing 610 may be in direct and tight contact.

[0063] In a further embodiment, the filter device 600 further includes a second seal 694 disposed between the second sealing cover 640 and the main housing portion 610 of the filter housing 600a to seal the gap between the second sealing cover 640 and the main housing portion 610. Optionally, the second seal 694 is located between the circumferential surface of the second sealing cover 640 and the inner wall surface of the main housing portion 610 for radial sealing. Further optionally, the second seal 694 can be a sealing ring made of rubber, and the sealing ring is fitted over the outside of the second sealing cover 640.

[0064] In this embodiment, the filter device 600 is provided with a second sealing element 694. The second sealing element 694 seals the gap between the second sealing cover 640 and the main housing 610, which helps to improve the sealing performance and prevent foreign objects from entering the filter chamber 611.

[0065] Of course, in other embodiments, the filter device 600 may not have a second seal 694, and the second sealing cover 640 and the main housing 610 may be in direct and tight contact.

[0066] In this embodiment, the filter device 600 may only have the first seal 693, only have the second seal 694, or both the first seal 693 and the second seal 694.

[0067] In an optional embodiment, refer to Figure 11 As shown, at least one of the first sealing cover 630 and the second sealing cover 640 includes a connected first cover body 631 and a first boss 632. The first boss 632 protrudes from the surface of the first cover body 631 and extends into the filter chamber 611. A first seal 693 is located between the first boss 632 of the first sealing cover 630 and the filter housing 600a, and a second seal 694 is located between the first boss 632 of the second sealing cover 640 and the filter housing 600a.

[0068] Optionally, the first protrusion 632 has an annular structure. The pressure plate 670 is connected to the first protrusion 632 of the first sealing cover 630 to separate the buffer cavity 632a and the filter cavity 611. In this case, the pressure plate 670, the first cover body 631 of the first sealing cover 630, and the first protrusion 632 together form the buffer cavity 632a. The first cover body 631 and the first protrusion 632 can be formed into an integral structure by injection molding or other methods. Alternatively, the first cover body 631 and the first protrusion 632 can be separate structures, which can be connected by welding or other methods. The structure of the first cover body 631 is the same as that of the corresponding first mounting port 612 or second mounting port 613. The first protrusion 632 can be a cylindrical structure, a prismatic structure, or the like.

[0069] In an optional embodiment, the filter device 600 further includes a first dustproof screen 691, which is connected to the pressure plate 670 and faces the through hole 671. Optionally, referring to... Figure 12 and Figure 15 As shown, the laying area of ​​the first dustproof net 691 is equal to the laying area of ​​the pressure plate 670. The edge of the first dustproof net 691 and the edge of the pressure plate 670 can be connected by welding, bonding or other means. The first dustproof net 691 can be located in the buffer cavity 632a or in the filter cavity 611.

[0070] In this embodiment, the filter device 600 is equipped with a first dustproof net 691. The first dustproof net 691 can block dust in the gas passing through the through hole 671 of the pressure plate 670 from entering the filter chamber 611, thus preventing dust and other foreign objects from entering the filter chamber 611 and clogging the filter body 620, which is beneficial to improving the cleanliness of the gas.

[0071] In an optional embodiment, the filter device 600 further includes a second dustproof net 692, which is connected to the filter housing 600a and faces the outlet end of the filter housing 600a. Optionally, the second dustproof net 692 is connected to the air outlet adapter 660 and faces the air inlet end of the air outlet adapter 660. The edge of the second dustproof net 692 can be connected to the air outlet adapter 660 by welding, bonding, or other methods. The second dustproof net 692 can be located inside the filter chamber 611 or inside the air outlet adapter 660.

[0072] In this embodiment, the filter device 600 is equipped with a second dustproof net 692. The second dustproof net 692 can prevent dust in the gas passing through the outlet end of the filter housing 600a from entering the ion migration tube 100, thereby avoiding dust and other foreign objects from affecting the detection process of the ion migration tube 100 and improving the cleanliness of the gas.

[0073] Of course, in other embodiments, the filter device 600 may not have the first dust filter 691 and the second dust filter 692.

[0074] In the scheme of this application, the ion migration tube 100 is provided with a detection inlet 102 communicating with the detection chamber 101, and the detection inlet 102 is used to allow the detection sample to enter the detection chamber 101. The ion migration tube 100 is also provided with a calibration outlet 103.

[0075] refer to Figures 1-3As shown, the ion migration detector also includes a calibration device 300. The inlet of the calibration device 300 can be connected to the calibration outlet 103, and the outlet of the calibration device 300 is connected to the detection inlet 102. Optionally, the calibration outlet 103 and the inlet of the calibration device 300 are connected through a first pipeline. The first end of the first pipeline is connected to the calibration outlet 103, and the second end of the first pipeline is connected to the inlet of the calibration device 300.

[0076] Optionally, the detection chamber 101 includes an ionization region 101a, with a calibration outlet 103 opposite to the ionization region 101a. That is, the calibration outlet 103 is connected to the ionization region 101a of the detection chamber 101. The detection chamber 101 is connected to the inlet of the calibration device 300 via the calibration outlet 103. The detection inlet 102 is located at the end of the ion migration tube 100, and the calibration outlet 103 is located on the side of the ion migration tube 100. Further optionally, the detection chamber 101 also includes a migration region 101b. The ionization region 101a is closer to the detection inlet 102, and the migration region 101b is farther from the detection inlet 102. The sample is ionized in the ionization region 101a and then migrates to the migration region 101b.

[0077] The ion migration detector also includes a thermal desorption device 110, which is used to thermally desorb the sample entering the ion migration tube 100. The outlet of the thermal desorption device 110 is connected to the detection inlet 102. The sample first undergoes thermal desorption in the thermal desorption device 110 before entering the ion migration tube 100. The thermal desorption device 110 is provided with a calibration inlet 110a, and the outlet of the calibration device 300 is connected to the calibration inlet 110a. That is, the outlet of the calibration device 300 is connected to the detection inlet 102 of the ion migration tube 100 through the thermal desorption device 110.

[0078] Optionally, the calibration inlet 110a is located on the side of the thermal desorption device 110, and the outlet end of the calibration device 300 and the calibration inlet 110a can be connected through a third pipeline.

[0079] In this embodiment, a calibration device 300 is added to the ion migration detector. The calibration device 300 is used to calibrate the gas flowing out of the calibration outlet 103, which helps to improve the detection accuracy of the ion migration tube 100. Moreover, a thermal desorption device 110 is further added to enrich and purify the target components in the sample, which helps to improve the accuracy and sensitivity of the analysis.

[0080] Of course, in other embodiments, the ion migration detector may not have the thermal desorption device 110, and the outlet end of the calibration device 300 may be directly connected to the detection inlet 102 of the ion migration tube 100.

[0081] In an optional embodiment, refer to Figures 7-9As shown, the calibration device 300 includes a calibration chamber 310, a calibration material 320, and a third sealing cover 330. The calibration chamber 310 is used to contain the calibration material 320, which is a solid particulate matter. The calibration material 320 is used to calibrate the gas inside the ion migration tube 100. The third sealing cover 330 is used to seal the calibration chamber 310. Specifically, the calibration chamber 310 has a connected calibration cavity 310a and a third mounting port 310b. The calibration cavity 310a is used to contain the calibration material 320, which is in contact with the cavity wall of the calibration cavity 310a. The calibration material 320 can enter the calibration cavity 310a through the third mounting port 310b.

[0082] Optionally, both the third mounting port 310b and the third sealing cover 330 can be square, circular, or other structures. This application embodiment does not limit the structure of the third mounting port 310b and the third sealing cover 330, as long as the third sealing cover 330 can close the third mounting port 310b.

[0083] The third sealing cover 330 is detachably disposed at the third mounting port 310b, that is, the third sealing cover 330 is detachably connected to the calibration cavity 310. Optionally, the third sealing cover 330 and the calibration cavity 310 can be connected by fasteners 900 such as screws or bolts. When the fasteners 900 are removed, the third sealing cover 330 can be detached from the calibration cavity 310, the third mounting port 310b is opened, and the calibration object 320 can extend out of the calibration cavity 310a through the third mounting port 310b. When the fasteners 900 are installed, the third sealing cover 330 is connected to the calibration cavity 310, the third mounting port 310b is closed, and the calibration object 320 cannot be detached from the calibration cavity 310a. The third sealing cover 330 and the calibration cavity 310 can also be connected by threads, that is, the circumferential surface of the third sealing cover 330 is provided with a third external thread, and the third mounting port 310b is provided with a third internal thread, with the third external thread and the third internal thread engaging. Of course, the third sealing cover 330 and the calibration cavity 310 can also be connected by other detachable means.

[0084] The calibrator 320 is a consumable item and needs to be replaced periodically. In this embodiment, after the calibrator 320 has been used for a period of time, the user can remove the third sealing cover 330 as needed, open the third installation port 310b, and take out the calibrator 320 from the calibration chamber 310a. A new calibrator 320 can then be placed through the third installation port 310b, ensuring that the calibrator 320 continuously and accurately calibrates the gas and ensuring the detection accuracy of the ion migration tube 100.

[0085] Optionally, the calibration device 300 further includes a second air inlet connector 380 and a second air outlet connector 390. The second air inlet connector 380 is connected to the calibration outlet 103, and the second air outlet connector 390 is connected to the detection inlet 102. The second air inlet connector 380 and the second air outlet connector 390 are respectively inserted into the calibration cavity 310, and are respectively connected to the calibration cavity 310a. Further optionally, the second air inlet connector 380 is located on the side of the calibration cavity 310, and the second air outlet connector 390 is located at the end of the calibration cavity 310.

[0086] In a further embodiment, reference is made to... Figure 9 As shown, the calibration device 300 further includes a third sealing element 340, which is disposed between the third sealing cover 330 and the calibration cavity 310. Optionally, the third sealing element 340 is disposed between the circumferential surface of the third sealing cover 330 and the inner wall surface of the calibration cavity 310 for radial sealing. The third sealing element 340 is a sealing ring, which can be made of rubber, and is fitted over the third sealing cover 330.

[0087] In this embodiment, the calibration device 300 is equipped with a third sealing element 340, which seals the gap between the third sealing cover 330 and the calibration cavity 310, thereby improving the sealing performance and preventing foreign objects from entering the calibration cavity 310a.

[0088] Of course, in other embodiments, the calibration device 300 may not have a third seal 340, and the third sealing cover 330 may be in direct and tight contact with the inner wall of the calibration cavity 310.

[0089] In a further embodiment, reference is made to... Figure 8 As shown, the third sealing cover 330 includes a connected second cover body 331 and a second protrusion 332. The second protrusion 332 protrudes from the surface of the second cover body 331 and extends into the calibration cavity 310a. Optionally, the second cover body 331 and the second protrusion 332 can be formed into an integral structure by injection molding or other methods. Of course, they can also be separate structures, which can be connected by bonding or other methods. The second cover body 331 can be a circular structure, a square structure, etc., and the structure of the second cover body 331 is the same as that of the third mounting port 310b. The second protrusion 332 can be a prism-shaped structure, a cylindrical structure, etc. The second cover body 331 and the calibration cavity 310 can be detachably connected by fasteners 900 such as bolts and screws. The third seal 340 is located between the second boss 332 and the calibration cavity 310. While the second boss 332 extends into the calibration cavity 310a, the third seal 340 seals the gap between the second boss 332 and the calibration cavity 310.

[0090] In an optional embodiment, refer to Figure 7 and Figure 8 As shown, the second cover 331 is also provided with a hook 333. The hook 333 is located on the side of the second cover 331 facing away from the second protrusion 332. In this way, when it is necessary to remove the third sealing cover 330, the connection between the third sealing cover 330 and the calibration cavity 310 is released, and the hook 333 is pulled to facilitate the direct separation of the third sealing cover 330 from the calibration cavity 310.

[0091] In the scheme of this application, in the calibration device 300 and the filter device 600, only the third sealing cover 330 of the calibration device 300 can be detachable, allowing the calibration element 320 to be replaced; or only the first sealing cover 630 of the filter device 600 can be detachable, allowing the filter element 620 to be replaced; or both the third sealing cover 330 of the calibration device 300 and the first sealing cover 630 of the filter device 600 can be detachable, allowing both the calibration element 320 and the filter element 620 to be replaced. In short, adopting a detachable structure allows for the replacement of parts of some functional components of the ion migration detector, enabling it to continue to perform its functions and avoiding any impact on the detection effect of the ion migration tube 100, thus helping to ensure detection accuracy.

[0092] In an optional embodiment, refer to Figure 1 As shown, the ion migration detector also includes a selection control valve 400, which can be, but is not limited to, a solenoid valve. The selection control valve 400 has a first air inlet 410, a first air outlet 420, and a second air outlet 430. The first air inlet 410 is connected to the calibration outlet 103. Optionally, the second air outlet 430 of the selection control valve 400 is connected to the second air inlet connector 380. The first air outlet 420 is used to connect to a collection device, which can be part of the ion migration detector or a part other than the ion migration detector. The second air outlet 430 is connected to the inlet end of the calibration device 300. The first air inlet 410 is selectively connected to one of the first air outlet 420 and the second air outlet 430.

[0093] Optionally, the first air inlet 410 and the calibration outlet 103, the first air outlet 420 and the collection device, and the second air outlet 430 and the inlet end (i.e. the second air inlet connector 380) of the calibration device 300 can all be connected through the second pipeline.

[0094] Specifically, when the selection control valve 400 is in the first open state, the first air inlet 410 is connected to the first air outlet 420, and the calibration outlet 103 is connected to the collection device. At this time, the collection device can collect gas for sampling. When the selection control valve 400 is in the second open state, the first air inlet 410 is connected to the second air outlet 430, and the calibration outlet 103 is connected to the inlet end of the calibration device 300. The gas flowing out of the calibration outlet 103 enters the ion migration tube 100 through the detection inlet 102 after passing through the calibration device 300.

[0095] In this embodiment, a selection control valve 400 is added so that the gas flowing out of the calibration outlet 103 can be collected or used as a carrier gas to blow the calibration substance 320 into the ion migration tube 100. That is, the gas flowing out of the calibration outlet 103 has different uses, which is beneficial to expanding the functions.

[0096] In a further embodiment, reference is made to... Figure 8 and Figure 9 As shown, the calibration device 300 also includes a temperature detection element 350 and a heating element 360. The temperature detection element 350 is used to detect the temperature of the calibration chamber 310. The temperature detection element 350 is disposed in the calibration chamber 310 and can be a thermistor, temperature sensor, etc. The heating element 360 is connected to the calibration chamber 310 so that the heating element 360 heats the calibration chamber 310. The heating element 360 can be a heating rod, heating wire, etc. The embodiments of this application do not limit the specific type and structure of the temperature detection element 350 and the heating element 360.

[0097] Temperature sensing element 350 is communicatively connected to heating element 360. Optionally, refer to... Figure 2 and Figure 3 As shown, the ion migration detector also includes a control board 830 and a data acquisition module 840. The temperature detection element 350 is communicatively connected to the data acquisition module 840, and the temperature information detected by the temperature detection element 350 can be transmitted to the data acquisition module 840. Furthermore, the data acquisition module 840 and the heating element 360 are communicatively connected to the control board 830, respectively. The control board 830 can control the heating element 360 according to the information from the data acquisition module 840 to control the temperature of the calibration object 320, so as to avoid the temperature of the calibration object 320 being too high or too low. The communication connection method can be a wired connection or a wireless connection. The wired connection can be achieved through an electrical connection cable, and the wireless connection can be, but is not limited to, Bluetooth connection or WiFi connection.

[0098] In this embodiment, the heating element 360 heats the calibration chamber 310, which in turn heats the calibration material 320, causing the calibration material 320 to vaporize. This makes it easier for the calibration material 320 to smoothly enter the ion migration tube 100 under the action of the carrier gas, and also facilitates the smooth progress of the calibration process.

[0099] Of course, in other embodiments, the heating element 360 and the temperature detection element 350 may not be connected in communication, and the user can control the heating element 360 according to the temperature information detected by the temperature detection element 350.

[0100] In an optional embodiment, refer to Figures 7-9 As shown, the calibration device 300 also includes a heat insulation layer 370, which is disposed on the outer surface of the calibration cavity 310 of the calibration device 300. Optionally, the heat insulation layer 370 is made of heat insulation material, which may be, but is not limited to, stainless steel; the heat insulation layer 370 has a ring structure and is sleeved on the outer surface of the calibration cavity 310 of the calibration device 300.

[0101] In this embodiment, the calibration device 300 is equipped with an insulation layer 370 to keep the calibration cavity 310 warm, thus preventing heat loss from the calibration cavity 310. This allows the heating element 360 to accurately heat the calibration object 320 through the calibration cavity 310, thereby helping the calibration object 320 to quickly reach the appropriate temperature.

[0102] Of course, in other embodiments, the calibration device 300 may not have an insulation layer 370, and the outer surface of the calibration cavity 310 may be directly exposed.

[0103] In this application, the ion migration detector further includes a sampling gas pump 200, which is used to evacuate the internal space of the ion migration tube 100. Specifically, the space of the detection chamber 101 includes an ionization region 101a, and a calibration outlet 103 is opposite to the ionization region 101a. The inlet end of the sampling gas pump 200 is connected to the calibration outlet 103, and the detection chamber 101 is connected to the inlet end of the sampling gas pump 200 through the calibration outlet 103, at which time the calibration outlet 103 serves as a suction port. The outlet end of the sampling gas pump 200 can be connected to the inlet end of the calibration device 300. Optionally, the outlet end of the sampling gas pump 200 is connected to the first air inlet 410 of the selection control valve 400.

[0104] Thus, when the sampling gas pump 200 is working, it can draw air from the ionization region 101a of the detection chamber 101 through the calibration outlet 103, thereby reducing the gas pressure in the ionization region 101a of the detection chamber 101. At the same time, the gas drawn by the sampling gas pump 200 serves as a carrier gas, blowing the calibrator 320 of the calibration device 300 into the calibration inlet 110a, and the calibrator 320 enters the ion migration tube 100 through the calibration inlet 110a.

[0105] In this embodiment, the ion migration detector is equipped with a sampling gas pump 200. The suction force of the sampling gas pump 200 is used to draw the detection chamber 101 through the calibration outlet 103, thereby reducing the gas pressure in the ionization region 101a of the detection chamber 101. As a result, the gas pressure in the ionization region 101a is lower than the gas pressure at the detection inlet 102, and the detection sample at the detection inlet 102 is rapidly drawn into the detection chamber 101. The speed at which the detection sample enters the ion migration tube 100 is increased, which is beneficial to improving the detection speed.

[0106] Moreover, the gas drawn by the sampling gas pump 200 is used as the carrier gas, which blows the calibrator 320 into the ion migration tube 100, which helps to improve the calibration efficiency. At the same time, the carrier gas assists the detection sample in entering the ion migration tube 100, which is more conducive to the smooth entry of the detection sample into the ion migration tube 100.

[0107] In the scheme of this application, reference is made to Figure 1 As shown, the ion migration detector also includes a circulating gas pump 500. The inlet end of the circulating gas pump 500 is connected to the circulating gas outlet 105, and the outlet end of the circulating gas pump 500 is connected to the circulating gas inlet 104. The ion migration tube 100 and the circulating gas pump 500 together form a circulating gas path.

[0108] Optionally, the circulating gas inlet 104 is opposite to the migration region 101b of the detection chamber 101, and the circulating gas outlet 105 is opposite to the ionization region 101a of the detection chamber 101. The inlet end of the circulating gas pump 500 and the circulating gas outlet 105 can be connected through a third pipeline, and the outlet end of the circulating gas pump 500 and the circulating gas inlet 104 can be connected through a fourth pipeline. The filter device 600 can be set between the inlet end of the circulating gas pump 500 and the circulating gas outlet 105, or it can be set between the outlet end of the circulating gas pump 500 and the circulating gas inlet 104. In short, the gas in the circulating gas path can be filtered by the filter device 600.

[0109] In this embodiment, the ion migration detector is equipped with a circulating gas pump 500. Under the action of the circulating gas pump 500, the gas flows rapidly in the circulating gas path. The ions ionized in the detection sample can collide with the circulating gas molecules, thereby distinguishing the time it takes for different types of ions to reach the flange of the ion migration tube 100, thus achieving the purpose of detection.

[0110] In this embodiment, the ion migration detector is equipped with both a sampling gas pump 200 and a circulating gas pump 500. Of course, it is also possible to only provide one of the sampling gas pump 200 and the circulating gas pump 500.

[0111] In the scheme of this application, reference is made to Figures 4-6As shown, at least one of the circulating air pump 500 and the sampling air pump 200 includes an air pump body 210, an air pump adapter 220, a first air inlet connector 230, and a first air outlet connector 240. The air pump body 210 serves as the main functional component of either the circulating air pump 500 or the sampling air pump 200, and is used to draw in gas. The air pump adapter 220 is used to mount the air pump body 210, and is provided with an air inlet channel 220a and an air outlet connector 240. The air inlet end 211 and the first air inlet connector 230 of the air pump body 210 both extend into the air inlet channel 220a. The air outlet end 212 and the first air outlet connector 240 of the air pump body 210 both extend into the air outlet channel 220b. Moreover, the first air inlet connector 230 is connected to the air inlet end 211 through the air inlet channel 220a, and the first air outlet connector 240 is connected to the air outlet end 212 through the air outlet channel 220b.

[0112] With this configuration, the gas entering through the first air inlet connector 230 enters the air pump body 210 through the air inlet channel 220a and the air inlet end 211, and then flows out through the first air outlet connector 240 through the air outlet end 212 and the air outlet channel 220b.

[0113] Optionally, refer to Figure 6 As shown, the air pump adapter 220 includes a first adapter 221 and a second adapter 222 connected together. The air inlet channel 220a and the air outlet channel 220b are both disposed on the second adapter 222. The first adapter 221 and the second adapter 222 can be connected by fasteners 900 such as bolts. A space for accommodating the air pump body 210 is formed between the first adapter 221 and the second adapter 222. Moreover, a part of the air pump body 210 extends beyond the first adapter 221.

[0114] In this embodiment, at least one of the circulating air pump 500 and the sampling air pump 200 is provided with an air pump adapter 220. The air inlet end 211 and the first air inlet connector 230 of the air pump body 210 are respectively inserted into the air pump adapter 220 to achieve communication between the air inlet end 211 and the first air inlet connector 230 of the air pump body 210. At the same time, the air outlet end 212 and the first air outlet connector 240 of the air pump body 210 are respectively inserted into the air pump adapter 220 to achieve communication between the air outlet end 212 and the first air outlet connector 240 of the air pump body 210, so as to facilitate the connection of the first air inlet connector 230 and the first air outlet connector 240 to the air pump body 210.

[0115] Of course, in other embodiments, the circulating air pump 500 and the sampling air pump 200 may not have the air pump adapter 220. The first air inlet connector 230 is directly connected to the air inlet end 211 of the air pump body 210, and the first air outlet connector 240 is directly connected to the air outlet end 212 of the air pump body 210.

[0116] In a further embodiment, reference is made to... Figure 5 and Figure 6 As shown, at least one of the sampling air pump 200 and the circulating air pump 500 further includes a fourth seal 250. The fourth seal 250 is provided between the air inlet end 211 and the air pump adapter 220 to seal the air inlet channel 220a, that is, to seal the gap between the air inlet end 211 and the air pump adapter 220. Optionally, the fourth seal 250 can be a sealing ring, which can be made of rubber and is fitted over the outside of the air inlet end 211. Of course, the fourth seal 250 can also be any other seal besides a sealing ring.

[0117] In this embodiment, a fourth sealing element 250 is added between the air inlet end 211 and the air pump adapter 220, which helps to improve the sealing performance of the air inlet channel 220a and prevents gas from flowing out through the gap between the air inlet end 211 and the air pump adapter 220.

[0118] In a further embodiment, reference is made to... Figure 5 and Figure 6 As shown, a fourth sealing element 250 is provided between the air outlet end 212 and the air pump adapter 220 to seal the air outlet channel 220b, that is, to seal the gap between the air outlet end 212 and the air pump adapter 220.

[0119] In this embodiment, a fourth sealing element 250 is added between the air outlet end 212 and the air pump adapter 220, which helps to improve the sealing performance of the air outlet channel 220b and prevents gas from flowing out through the gap between the air outlet end 212 and the air pump adapter 220.

[0120] Of course, in other embodiments, the fourth seal 250 may not be provided between the air inlet end 211 and the air pump adapter 220, and the fourth seal 250 may not be provided between the air outlet end 212 and the air pump adapter 220.

[0121] In an optional embodiment, refer to Figure 1 As shown, the ion migration detector also includes a flow detection element 710. The flow detection element 710 can be, but is not limited to, a flow sensor. The flow detection element 710 is disposed in the circulating gas path to detect the flow rate of the circulating gas path. Optionally, the flow detection element 710 can be disposed between the filter device 600 and the circulating gas inlet 104, or it can be disposed between the circulating gas pump 500 and the filter device 600. In this embodiment, the placement of the flow detection element 710 is not limited, as long as it can detect the flow rate of the circulating gas path.

[0122] Furthermore, the flow detection element 710 is communicatively connected to the circulating air pump 500. Optionally, the ion migration detector also includes the data acquisition module 840 and control board 830 mentioned above. The flow detection element 710 is communicatively connected to the data acquisition module 840, and the flow information detected by the flow detection element 710 is transmitted to the data acquisition module 840. The data acquisition module 840 and the circulating air pump 500 are respectively communicatively connected to the control board 830, and the control board 830 controls the flow rate of the circulating air pump 500 based on the information from the data acquisition module 840. The communication connection can be wired or wireless. The wired connection can be achieved through an electrical cable, while the wireless connection can be, but is not limited to, Bluetooth or WiFi.

[0123] In this embodiment, the flow rate of the circulating air path is monitored by the flow detection element 710. Moreover, the flow detection element 710 is communicatively connected to the circulating air pump 500 and adjusts the circulating air pump 500 in real time according to the flow rate change, thereby adjusting the flow rate of the circulating air path in real time to ensure that the flow rate of the circulating air path is maintained within a suitable range and to avoid the flow rate of the circulating air path being too large or too small.

[0124] Of course, in other embodiments, the flow detection element 710 and the circulating air pump 500 may not be communicatively connected, and the user can adjust the circulating air pump 500 according to the flow detected by the flow detection element 710.

[0125] In an optional embodiment, the ion migration detector further includes a humidity and temperature detection element 720. The humidity and temperature detection element 720 can be, but is not limited to, a humidity and temperature sensor. The humidity and temperature detection element 720 is disposed in the circulating gas path to detect the humidity and temperature of the gas in the circulating gas path. Optionally, the humidity and temperature detection element 720 is communicatively connected to a data acquisition module 840, which can acquire humidity and temperature information. The communication connection can be wired or wireless. A wired connection can be achieved through an electrical cable, while a wireless connection can be, but is not limited to, Bluetooth or WiFi.

[0126] Thus, the filtration effect of the filter device 600 is judged based on the humidity of the gas in the circulating gas path, and then it is determined whether the filter element 620 needs to be replaced; since temperature changes will cause gas pressure changes, the gas pressure is judged based on the temperature of the gas in the circulating gas path, and then it is determined whether the gas in the ion migration tube 100 needs to be calibrated.

[0127] In summary, in the embodiments of this application, the temperature detection element 350, the flow detection element 710, and the humidity temperature detection element 720 are respectively connected to the data acquisition module 840, and the control board 830 is respectively connected to the circulating air pump 500, the sampling air pump 200, and the selective control valve. The control valve can control the circulating air pump 500, the sampling air pump 200, and the selective control valve.

[0128] In the scheme of this application, reference is made to Figure 2 and Figure 3 As shown, the ion migration detector also includes a support base 800 and a shock absorber 810. The support base 800 provides a mounting foundation for each component. The shock absorber 810 and the ion migration tube 100 are both mounted on the support base 800. Optionally, the selection control valve 400, calibration device 300, filter device 600, flow detection element 710, and humidity and temperature detection element 720 are all mounted on the support base 800. Furthermore, the sampling air pump 200 and the circulating air pump 500 are both mounted on the shock absorber 810. The shock absorber 810 can be, but is not limited to, a shock-absorbing pad, and the shock absorber 810 uses a cushioning material.

[0129] Among them, the shock absorber 810, ion migration tube 100, selection control valve 400, calibration device 300, filter device 600, flow detection element 710 and humidity and temperature detection element 720 can be installed on the support base 800 by means of detachable connection such as bolts, or by means of non-detachable connection such as welding; similarly, the pump body 210 of sampling air pump 200 and circulating air pump 500 can be connected to the shock absorber 810 by means of non-detachable connection such as bonding or welding, or by means of detachable connection such as bolts.

[0130] In this embodiment, a support base 800 is provided to provide an installation foundation for each component, and a shock absorber 810 is added to reduce the vibration caused by the sampling air pump 200 and the circulating air pump 500 during operation, thereby avoiding excessive vibration that could affect the operation of other components.

[0131] Of course, in other embodiments, the ion migration detector may not have the shock absorber 810, and the sampling gas pump 200 and the circulating gas pump 500 may be directly mounted on the support base 800.

[0132] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An ion migration detector, characterized in that, include: An ion migration tube (100) is provided with a detection chamber (101), a circulating gas inlet (104) and a circulating gas outlet (105), wherein the circulating gas inlet (104) and the circulating gas outlet (105) are respectively connected to the detection chamber (101); A filtration device (600) includes a filter housing (600a), a filter body (620), a pressure plate (670), and a gas guide pipe (680). The inlet end of the filter housing (600a) is connected to the circulating gas outlet (105), and the outlet end of the filter housing (600a) is connected to the circulating gas inlet (104). The pressure plate (670) is disposed inside the filter housing (600a) and divides the internal space of the filter housing (600a) into a filter chamber (611) and a buffer chamber (632a). The pressure plate (670) is provided with a plurality of through holes (671) at intervals. The buffer chamber (632a) is connected to the filter chamber (611) through the through holes (671). The air guide tube (680) and the filter body (620) are both located in the filter chamber (611), and the air guide tube (680) passes through the pressure plate (670) and communicates with the buffer chamber (632a). The inlet end of the filter housing (600a), the air guide tube (680), the buffer chamber (632a), the filter chamber (611), and the outlet end of the filter housing (600a) are connected in sequence.

2. The ion migration detector according to claim 1, characterized in that, The filter housing (600a) includes a main housing (610) and a first sealing cover (630). The main housing (610) is provided with a filter chamber (611) and a first mounting port (612) that are connected to each other. The filter body (620) can enter the filter chamber (611) through the first mounting port (612). The first sealing cover (630) is detachably disposed at the first mounting port (612).

3. The ion migration detector according to claim 2, characterized in that, The filter housing (600a) further includes a second sealing cover (640), an air inlet adapter (650), and an air outlet adapter (660). The main housing (610) is also provided with a second mounting port (613), which communicates with the filter chamber (611). The second sealing cover (640) is detachably disposed at the second mounting port (613). The air inlet adapter (650) and the air outlet adapter (660) are respectively disposed on the second sealing cover (640), and the air inlet adapter (650) and the air outlet adapter (660) are respectively communicated with the filter chamber (611).

4. The ion migration detector according to claim 2 or 3, characterized in that, The filter device (600) further includes a first seal (693), which is disposed between the first sealing cover (630) of the filter housing (600a) and the main housing portion (610); And / or, the filter device (600) further includes a second seal (694) disposed between the second sealing cover (640) of the filter housing (600a) and the main housing portion (611).

5. The ion migration detector according to claim 1, characterized in that, The filter device (600) further includes a first dustproof net (691), which is connected to the pressure plate (670) and is opposite to the through hole (671); And / or, the filter device (600) further includes a second dust screen (692) connected to the filter housing (610), and the second dust screen (692) is opposite to the outlet end of the filter housing (610).

6. The ion migration detector according to claim 1, characterized in that, The ion migration tube (100) is provided with a detection inlet (102) and a calibration outlet (103) communicating with the detection chamber (101). The detection inlet (102) is used to allow the detection sample to enter the detection chamber (101). The ion migration detector also includes a calibration device (300) and a thermal desorption device (110). The inlet of the calibration device (300) can be connected to the calibration outlet (103), and the outlet of the thermal desorption device (110) is connected to the detection inlet (102). The thermal desorption device (110) is provided with a calibration inlet (110a), and the outlet of the calibration device (300) is connected to the calibration inlet (110a).

7. The ion migration detector according to claim 6, characterized in that, The calibration device (300) includes a calibration chamber (310), a calibration object (320), and a third sealing cover (330). The calibration chamber (310) has a communicating calibration cavity (310a) and a third mounting port (310b). The calibration object (320) can enter the calibration cavity (310a) through the third mounting port (310b). The third sealing cover (330) is detachably disposed at the third mounting port (310b). The calibration device (300) further includes a third seal (340) disposed between the third sealing cover (330) and the calibration cavity (310).

8. The ion migration detector according to claim 6 or 7, characterized in that, The calibration device (300) further includes a heat insulation layer (370), which is disposed on the outer surface of the calibration cavity (310) of the calibration device (300).

9. The ion migration detector according to claim 6, characterized in that, The ion migration detector further includes at least one of a circulating gas pump (500) and a sampling gas pump (200), wherein the inlet end of the circulating gas pump (500) is connected to the circulating gas outlet (105) and the outlet end of the circulating gas pump (500) is connected to the circulating gas inlet (104). The space of the detection chamber (101) includes an ionization region (101a), the calibration outlet (103) is opposite to the ionization region (101a), the detection chamber (101) is connected to the inlet end of the sampling gas pump (200) through the calibration outlet (103), and the outlet end of the sampling gas pump (200) can be connected to the inlet end of the calibration device (300).

10. The ion migration detector according to claim 9, characterized in that, At least one of the circulating air pump (500) and the sampling air pump (200) includes an air pump body (210), an air pump adapter (220), a first air inlet connector (230), and a first air outlet connector (240). The air pump adapter (220) is provided with an air inlet channel (220a) and an air outlet channel (220b). The air inlet end (211) of the air pump body (210) and the first air inlet connector (230) both extend into the air inlet channel (220a). The air outlet end (212) of the air pump body (210) and the first air outlet connector (240) both extend into the air outlet channel (220b). The first air inlet connector (230) is connected to the air inlet end (211) through the air inlet channel (220a), and the first air outlet connector (240) is connected to the air outlet end (212) through the air outlet channel (220b).

11. The ion migration detector according to claim 10, characterized in that, At least one of the circulating air pump (500) and the sampling air pump (200) further includes a fourth seal (250). The fourth seal (250) is provided between the air inlet end (211) and the air pump adapter (220) to seal the air inlet passage (220a), and / or the fourth seal (250) is provided between the air outlet end (212) and the air pump adapter (220) to seal the air outlet passage (220b).

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