Device and method for improving ion mobility spectrometry receiving signal

Abstract

The invention relates to a device and method for improving an ion mobility spectrometry receiving signal, the device comprises a Faraday disc, an insulating column, a Faraday disc shielding cylinder, a disc front insulating ring and an insulating nut, the Faraday disc comprises a metal disc and a metal rod, the metal rod is inserted into the hollow insulating column, the metal rod is provided with an external thread matched with the insulating nut, and the insulating column is provided with an external thread matched with the insulating nut. Signal pin grooves are formed in the tail ends, away from the metal disc side, of the metal rods; one end of the hollow insulating column is inserted into the Faraday disc shielding cylinder, and the other end of the hollow insulating column isolates and insulates the Faraday disc and the Faraday disc shielding cylinder; an air hole is formed in the Faraday disc shielding cylinder, a mounting groove is formed in the bottom surface of the Faraday disc shielding cylinder, the metal disc can be mounted in the disc front insulating ring, and a bulge matched with the mounting groove is arranged on the top surface of the disc front insulating ring. Through the structural design between the Faraday disc and the disc front insulation ring, the consistency of the distance between the Faraday disc and the end face of the disc front insulation ring is guaranteed, and the strength, reliability and consistency of transmission signals are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ion mobility spectrometry detection, and in particular to a device and method for improving ion mobility spectrometry receiving signals. Background Art

[0002] Ion mobility spectrometry (IMS) is a technique for analyzing chemical substances by ionizing gas phase molecules with an ionization source and using the difference in migration speeds of different gas phase ions in the same electric field. It has been widely used in the rapid screening and detection of explosives, drugs and poisons on site.

[0003] In the ion mobility spectrometer migration tube, the Faraday disk of the ion receiving device is responsible for receiving and transmitting extremely weak signals at the nanoampere level. An insulating spacer and a metal grid are provided before the Faraday disk. There is usually a DC electric field of several hundred volts between the Faraday disk and the metal grid. During the transmission of the electric signal, the smaller the distance between the Faraday disk and the metal grid, the stronger the electric signal transmission, but there is a greater risk of high-voltage current breakdown; the larger the distance, the greater the electric signal loss and the lower the signal; in addition, the consistency of the distance will also affect the signal difference of each ion mobility tube, so it is very important to control the reliability and consistency of the distance.

[0004] Liu Chifeng and others disclosed an ion mobility spectrometry ion receiving device (patent number 201911197427.4), including a Faraday disk seat, a Faraday disk, a first insulating spacer pad with a hole in the middle, an ion grid and a second insulating spacer pad with a hole in the middle; by arranging a first step structure on the Faraday disk seat, and arranging a second step structure and a third step structure on the first insulating spacer pad, the connection structure between the Faraday disk and the Faraday disk seat, between the first insulating spacer pad and the Faraday disk seat, between the first insulating spacer pad and the Faraday disk seat, between the ion grid and the first insulating spacer pad, and between the first insulating spacer pad and the second insulating spacer pad is simple and easy to install. Compared with the structure in which the traditional pole pieces are connected together by welding wires or electronic components, the ion receiving device of the invention has the advantages of simple and reliable installation structure and convenient and quick assembly operation.

[0005] However, a boss is provided in the middle of the Faraday disk, and the boss is opposite to the middle opening position of the first insulating spacer and the mesh position of the ion grid. The distance between the boss and the end face of the first insulating spacer / ion grid is 0.3-0.7mm. This distance is very small and is controlled by an infinite component. It is difficult to ensure the repeatability of the distance, resulting in differences in signal strength and discharge between the boss and the ion grid, which damages the signal receiving device.

[0006] An ion mobility spectrometer ion signal extraction and sealing device (patent number ZL201210536367.6) invented by Li Haiyang and others is a Faraday disk ion current signal extraction device with sealing function, including a Faraday disk, a metal shielding tube, a hollow metal shielding adapter, an insulator, a hollow sealed insulating ferrule, a metal connecting nut and a signal extraction connector, so as to achieve good sealing and reliable micro-current signal extraction, and prevent the loosening of the Faraday disk and its contact with the shielding grid caused by heating, vibration and other factors. However, its trapezoidal sealed insulating ferrule will soften and deform during the use of alternating hot and cold, resulting in loosening of the Faraday disk and signal fluctuations, and also causing reduced sealing and air leakage.

[0007] An ion receiving device for ion mobility spectrometry invented by Li Haiyang and others (patent number ZL201110428494.X) is a Faraday disk micro-current signal extraction device with a sealing function, including a Faraday disk, an O-ring, an insulating sealing pressure ring, a sealing nut, a ferrule, a gold-plated spring pin signal shielding lead-out wire, a clamping nut, an adapter, a Faraday disk shielding cylinder and a Faraday disk insulating pad, etc., to achieve sealed and reliable micro-current signal extraction and prevent failure caused by vibration, heating and other factors. However, the Faraday disk, the annular Faraday disk insulating pad, the shielding cylinder, the O-ring, and the insulating sealing pressure ring are tightened and fastened by a sealing nut. The connection and cooperation between the above components are circular and slidable. In particular, the Faraday disk is also circular in shape. Therefore, it is difficult to tighten the circular Faraday disk and the sealing nut. It is easy to loosen during use, resulting in fluctuations or even loss of the collected signal. Summary of the invention

[0008] In order to solve the above-mentioned technical problems, a device and method for improving the received signal of ion mobility spectrometry are provided.

[0009] The technical means adopted by the present invention are as follows:

[0010] A device for improving the reception signal of ion mobility spectrometry comprises a Faraday disk, a hollow insulating column, a Faraday disk shielding cylinder, an insulating ring in front of the disk and an insulating nut. The Faraday disk comprises a metal disk and a metal rod. The metal rod is inserted into the hollow insulating column. The metal rod is provided with an external thread matching with the insulating nut. The end of the metal rod away from the metal disk is provided with a groove matching with a signal pin. One end of the hollow insulating column is inserted into the Faraday disk shielding cylinder, and the other end isolates and insulates the Faraday disk from the Faraday disk shielding cylinder. The Faraday disk shielding cylinder is provided with an air hole, and the bottom surface of the Faraday disk shielding cylinder is provided with a mounting groove. The metal disk can be installed in the insulating ring in front of the disk. The top surface of the insulating ring in front of the disk is provided with a protrusion matching with the mounting groove. The insulating ring in front of the disk is a hollow structure.

[0011] Furthermore, the metal disk is a regular shape, and its cross-sectional area is greater than or equal to the cross-sectional area of ​​the metal rod.

[0012] Furthermore, the metal disk includes a hexagonal metal disk, an octagonal metal disk, a gear-shaped metal disk, a circular metal disk, and a quadrilateral metal disk.

[0013] Furthermore, the overall cross-section of the Faraday disk is T-shaped or the end of the T-shape is stepped, and the cross-section of the hollow insulating column is T-shaped.

[0014] Furthermore, the diagonal opposite side / diameter of the metal disk is greater than or equal to the diameter of the large end of the hollow insulating column.

[0015] Furthermore, the minimum diameter of the hollow insulating column is less than or equal to the minimum diameter of the Faraday disk shielding cylinder.

[0016] Furthermore, the Faraday disk has a side length of 6-20 mm and a diagonal length of 6.9-23.1 mm.

[0017] Furthermore, the inner diameter of the insulating ring in front of the disk ranges from 6.4 to 21.5 mm.

[0018] Furthermore, a sealing gasket is provided between the Faraday disk and the hollow insulating column, and / or between the hollow insulating column and the Faraday disk shielding cylinder.

[0019] The present invention also discloses a method based on the above-mentioned device for improving the ion mobility spectrum receiving signal. There is a gap between the inner circle of the insulating ring in front of the disk and the opposite sides of the T-shaped hexagonal Faraday disk, which serves as a channel for the uniform circulation of the floating gas flow. The effective receiving area of ​​the Faraday disk is adjusted by adjusting the size of the inner diameter of the insulating ring in front of the disk and the size of the diagonal opposite sides / diameter of the Faraday disk.

[0020] Compared with the prior art, the present invention has the following advantages: the present invention ensures the consistency of the end face distance between the Faraday disk and the insulating ring in front of the disk through the structural design between the Faraday disk and the insulating ring in front of the disk, which not only improves the signal strength, but also avoids the failure of high-voltage discharge caused by assembly differences, and improves the strength, reliability and consistency of the transmitted signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 This is an assembly diagram of a Faraday disk according to an embodiment of the present invention.

[0023] Figure 2 It is a front view of an embodiment of the present invention.

[0024] Figure 3 It is an exploded view of an embodiment of the present invention.

[0025] Figure 4 This is an analysis diagram of acetone gas in an embodiment of the present invention.

[0026] Figure 5 This is an analysis diagram of the acetone-butanone mixed liquid gas in an embodiment of the present invention.

[0027] Figure 6 This is a structural diagram of an expanded implementation mode 1 of the present invention.

[0028] Figure 7 This is a schematic structural diagram of an expanded implementation mode 2 of the present invention.

[0029] Figure 8 This is a structural diagram of an expanded implementation mode 3 of the present invention.

[0030] In the figure: 1. Insulating ring in front of the disk; 2. Faraday disk; 3. Hollow insulating column; 4. Faraday disk shielding tube; 5. Insulating nut; 6. Insulating gasket; 7. Fixing bolt; 8. Metal fixing disk; 9. Metal tube; 10. Insulating tube; 11. Floating air hole. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0035] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0036] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0037] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0038] like Figures 1 to 3 As shown, an embodiment of the present invention discloses a device for improving the reception signal of ion mobility spectrometry, comprising a Faraday disk 2, a hollow insulating column 3, a Faraday disk shielding tube 4, a disk front insulating ring 1 and an insulating nut 5, wherein the Faraday disk comprises a metal disk and a metal rod, the metal rod is inserted into the hollow insulating column, the metal rod is provided with an external thread matching with the insulating nut, and the end of the metal rod away from the metal disk is provided with a groove matching with the signal needle; one end of the hollow insulating column is inserted into the Faraday disk shielding tube, and the other end isolates and insulates the Faraday disk from the Faraday disk shielding tube; an air hole is provided on the Faraday disk shielding tube, and a mounting groove is provided on the bottom surface of the Faraday disk shielding tube, the metal disk can be installed in the disk front insulating ring, the top surface of the disk front insulating ring is provided with a protrusion matching with the mounting groove, and the disk front insulating ring is a hollow structure.

[0039] The metal disk is a regular shape, and its cross-sectional area is greater than or equal to the cross-sectional area of ​​the metal rod.

[0040] The metal disk includes a hexagonal metal disk, an octagonal metal disk, a gear-shaped metal disk, a circular metal disk, and a quadrilateral metal disk.

[0041] The overall cross-section of the Faraday disk is T-shaped or the end of the T-shape is stepped, and the cross-section of the hollow insulating column is T-shaped.

[0042] The diagonal opposite side / diameter of the metal disk is equal to or greater than the diameter of the large end of the hollow insulating post.

[0043] The minimum diameter of the hollow insulating column is less than or equal to the minimum diameter of the Faraday disk shielding tube.

[0044] The side length of the Faraday disk is 6-20 mm, and the diagonal length is 6.9-23.1 mm.

[0045] The inner diameter of the insulating ring in front of the disk ranges from 6.4 to 21.5 mm.

[0046] A sealing gasket is arranged between the Faraday disk and the hollow insulating column, and / or between the hollow insulating column and the Faraday disk shielding cylinder.

[0047] The present invention also discloses a method based on the above-mentioned device for improving the ion mobility spectrum receiving signal. There is a gap between the inner circle of the insulating ring in front of the disk and the opposite sides of the T-shaped hexagonal Faraday disk, which serves as a channel for the uniform circulation of the floating gas flow. The effective receiving area of ​​the Faraday disk is adjusted by adjusting the size of the inner diameter of the insulating ring in front of the disk and the size of the diagonal opposite sides / diameter of the Faraday disk.

[0048] As an optional implementation, the following specifications are used for matching: the hexagonal T-shaped Faraday disk has a side length of 20 mm, a diagonal length of 23.1 mm, and an inner diameter range of the insulating ring in front of the disk is 21.5±1.0 mm;

[0049] The hexagonal side length of the T-type Faraday disk is 16 mm, the diagonal length is 18.5 mm, and the inner diameter range of the insulating ring in front of the disk is 17.2 ± 0.8 mm;

[0050] The hexagonal side length of the T-type Faraday disk is 12 mm, the diagonal length is 13.9 mm, and the inner diameter range of the insulating ring in front of the disk is 13.0 ± 0.5 mm;

[0051] The hexagonal T-shaped Faraday disk has a side length of 8.5 mm, a diagonal length of 9.8 mm, and an inner diameter range of the insulating ring in front of the disk of 9.1 ± 0.3 mm;

[0052] The hexagonal side length of the T-type Faraday disk is 6 mm, the diagonal length is 6.9 mm, and the inner diameter range of the insulating ring in front of the disk is 6.4 ± 0.2 mm;

[0053] A sealing gasket may be added between the T-shaped Faraday disk and the T-shaped hollow insulating column, or between the T-shaped hollow insulating column and the Faraday disk shielding cylinder for sealing;

[0054] The materials of the T-shaped hollow insulating column and the insulating nut are plastics such as Peak, tetrafluoroethylene, ABS, or polycarbonate.

[0055] like Figure 4 , Figure 5 As shown, by adjusting the inner diameter of the insulating ring in front of the disk and the diagonal opposite sides of the T-shaped hexagonal Faraday disk, the effective receiving area of ​​the Faraday disk is increased, more ions are received, and the signal intensity and peak-to-peak separation of the ion mobility spectrum are improved.

[0056] Embodiment 1:

[0057] The hexagonal side length of the T-shaped Faraday disk is 6-20 mm, and the diagonal length is 6.9-23.1 mm;

[0058] The inner diameter of the insulating ring in front of the disk ranges from 6.4 to 21.5 mm;

[0059] The analytical conditions for ion mobility spectrometry were:

[0060] The temperature of the migration tube was room temperature 25°C, the inner diameter of the migration zone was 20mm and the length was 7cm, the high pressure was 6.7kv, the door opening time was 50us, the drift gas was 0.5L / min, the carrier gas was 0.3L / min, the drift gas and the carrier gas flowed correspondingly, and the gas outlet was in the middle of the reaction zone. Room temperature acetone was used as the dopant for analysis;

[0061] The hexagonal T-shaped Faraday disk has a side length of 20 mm, a diagonal length of 23.1 mm, and an inner diameter of the insulating ring in front of the disk of 20.5 mm;

[0062] like Figure 4 As shown, the migration time of acetone is 3.37ms, the peak height of acetone is 5.4V, and the half-peak width is 0.10ms;

[0063] Meanwhile, the diameter of the T-shaped circular Faraday disk is 6 mm, and the inner diameter of the insulating ring in front of the disk is 22.5 mm;

[0064] The migration time of acetone is 3.33 ms, the peak height of acetone is 5.0 V, and the half-peak width is 0.13 ms;

[0065] Example 2

[0066] The hexagonal side length of the T-shaped Faraday disk is 6-20 mm, and the diagonal length is 6.9-23.1 mm;

[0067] The inner diameter of the insulating ring in front of the disk ranges from 6.4 to 21.5 mm;

[0068] The analytical conditions for ion mobility spectrometry were:

[0069] The temperature of the migration tube was room temperature 25°C, the inner diameter of the migration zone was 16mm and the length was 7cm, the high pressure was 6.7kv, the door opening time was 50us, the drift gas was 0.5L / min, the carrier gas was 0.3L / min, the drift gas and the carrier gas flowed correspondingly, and the gas outlet was in the middle of the reaction zone. A room temperature acetone butanone mixture was used as a dopant for analysis;

[0070] The hexagonal side length of the T-type Faraday disk is 16mm, the diagonal length is 18.5mm, and the inner diameter of the insulating ring in front of the disk is 18mm;

[0071] like Figure 5 As shown, the migration time of acetone is 3.37ms and the peak height is 2.0V, the migration time of acetone butanone complex is 3.57ms and the peak height is 4.4V, the half peak width is 0.10ms, the migration time of butanone is 3.76ms and the peak height is 2.9V, and the total peak height is 9.3V; the separation between the acetone butanone complex peak and the butanone peak is 1.12 (calculated as (3.76-3.57) / 1.7 / 0.10=1.12);

[0072] Meanwhile, the diameter of the T-shaped circular Faraday disk is 6 mm, and the inner diameter of the insulating ring in front of the disk is 16.4 mm;

[0073] The migration time of acetone is 3.33ms, the peak height is 1.1V, the migration time of acetone butanone complex is 3.52ms, the peak height is 2.5V, the half peak width is 0.09ms, the migration time of butanone is 3.72ms, the peak height is 1.6V, and the total peak height is 5.2V; the separation between the acetone butanone complex peak and the butanone peak is 1.3 (calculated as (3.72-3.52) / 1.7 / 0.09=1.3);

[0074] Example 3

[0075] The hexagonal side length of the T-shaped Faraday disk is 6-20 mm, and the diagonal length is 6.9-23.1 mm;

[0076] The inner diameter of the insulating ring in front of the disk ranges from 6.4 to 21.5 mm;

[0077] The analytical conditions for ion mobility spectrometry were:

[0078] The temperature of the migration tube was room temperature 25°C, the inner diameter of the migration zone was 20mm and the length was 8cm, the high pressure was 6.7kv, the door opening time was 50us, the drift gas was 0.5L / min, the carrier gas was 0.3L / min, the drift gas and the carrier gas flowed in the same direction, the gas outlet was at the end of the reaction zone, and the room temperature acetone butanone mixture was used as the dopant for analysis;

[0079] The hexagonal T-shaped Faraday disk has a side length of 8.5 mm, a diagonal length of 9.8 mm, and an inner diameter of the insulating ring in front of the disk of 9.1 mm;

[0080] The migration time of acetone is 4.1ms, the peak height is 0.4V, the migration time of acetone butanone complex is 4.4ms, the peak height is 1.4V, and the half peak width is 0.08ms. The migration time of butanone is 4.6ms, the peak height is 1.4V, and the total peak height is 2.3V. The separation between the acetone butanone complex peak and the butanone peak is 1.30 (calculated as (4.6-4.4) / 1.7 / 0.09=1.30);

[0081] Example 4

[0082] The hexagonal side length of the T-shaped Faraday disk is 6-20 mm, and the diagonal length is 6.9-23.1 mm;

[0083] The inner diameter of the insulating ring in front of the disk ranges from 6.4 to 21.5 mm;

[0084] A 1mm thick tetrafluoroethylene sealing gasket may be added between the T-shaped Faraday disk and the T-shaped hollow insulating column, and between the T-shaped hollow insulating column and the Faraday disk shielding cylinder for sealing;

[0085] The T-shaped hollow insulating column is made of polycarbonate, and the insulating nut is made of ABS plastic.

[0086] The analytical conditions for ion mobility spectrometry were:

[0087] The temperature of the migration tube was room temperature 30°C, the inner diameter of the migration zone was 20mm and the length was 8cm, the high pressure was 6.7kv, the door opening time was 50us, the drift gas was 0.5L / min, the carrier gas was 0.3L / min, the drift gas and the carrier gas flowed in the same direction, the gas outlet was at the end of the reaction zone, and room temperature acetone was used as the dopant for analysis;

[0088] The hexagonal side length of the T-shaped Faraday disk is 16 mm, the diagonal length is 18.5 mm, and the inner diameter range of the insulating ring in front of the disk is 17.2 mm;

[0089] Acetone peak height 7.6V, half peak width 0.11ms;

[0090] The hexagonal side length of the T-type Faraday disk is 6 mm, the diagonal length is 6.9 mm, and the inner diameter range of the insulating ring in front of the disk is 6.4 mm;

[0091] The acetone peak height is 3.3V and the half-peak width is 0.13ms.

[0092] Example 5

[0093] like Figure 6 As shown, as another expandable implementation method, the metal disk is also provided with pores, the number of the pores is 1-16, and the pore diameter is 0.6-3 mm; when there are multiple pores, they are evenly distributed on the metal disk.

[0094] During assembly, a hexagonal socket wrench or a hexagonal socket screwdriver holds the metal plate that fixes the T-shaped Faraday plate, cooperates with the insulating nut, and fixes the Faraday plate on the Faraday plate shielding tube, thereby achieving reliable assembly and sealing of the Faraday plate and ensuring stable reception and transmission of signals.

[0095] Example 6

[0096] In this embodiment, the metal rod and the insulating nut are assembled in other ways, specifically, as Figure 7As shown, it includes a front insulating ring and a Faraday disk. In addition, it also includes a metal fixed disk 8, an insulating cylinder 10, a metal cylinder 9, an insulating pad 6, a Faraday disk shielding cylinder 4 and a fixing bolt 7. The Faraday disk includes a metal disk and a metal rod. The metal rod is inserted into the metal cylinder. The outside of the metal cylinder is sleeved with the insulating cylinder. A hole for the insulating cylinder to pass through is provided in the middle of the metal fixed disk. A hole for the fixing bolt to pass through is also provided on it. A blind hole for the fixing bolt to be installed is provided on the inner wall of the Faraday disk shielding cylinder. The metal fixed disk is installed with the Faraday disk shielding cylinder by the fixing bolt. An insulating pad is provided between the metal fixed disk and the Faraday disk shielding cylinder. The metal fixed disk is provided inside the Faraday disk shielding cylinder. A groove is provided at the bottom end of the Faraday disk shielding cylinder. A protrusion matching the groove is provided on the top surface of the front insulating ring of the disk. A signal connector end is provided at one end of the metal fixed disk away from the Faraday disk. A floating air hole 11 is provided on the Faraday disk shielding cylinder.

[0097] Example 7

[0098] Similar to Example 6, in this embodiment, an external fixed Faraday disk for receiving ion mobility spectrometry signals comprises a front insulating ring of the disk, a Faraday disk, a metal fixed disk, an insulating cylinder, a metal cylinder, an insulating pad, a Faraday disk shielding cylinder and a fixing bolt 8. The Faraday disk comprises a metal disk and a metal rod. The metal rod is inserted into the metal cylinder. The outer part of the metal cylinder is sleeved with the insulating cylinder. A hole for installing the insulating cylinder is provided in the middle of the metal fixed disk. The two are interference fit. The two are tightly fit by compacting the insulating cylinder. A hole for the fixing bolt to pass through is also provided on the metal fixed disk. The outer wall of the Faraday disk shielding tube is provided with a threaded blind hole for installing fixing bolts, the metal fixed disk and the Faraday disk shielding tube are installed by fixing bolts, an insulating pad is provided between the metal fixed disk and the Faraday disk shielding tube, the bottom end of the Faraday disk shielding tube is provided with a groove, and the top surface of the insulating ring in front of the disk is provided with a protrusion matching the groove. After installation, a metal fixed disk-insulating pad-Faraday disk shielding tube-insulating ring in front of the disk structure is formed, and a signal connector end is provided at the end of the metal fixed disk away from the Faraday disk.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for improving ion mobility spectrometry receiving signals, characterized in that: It includes a Faraday disk, a hollow insulating column, a Faraday disk shielding tube, an insulating ring in front of the disk and an insulating nut. The Faraday disk includes a metal disk and a metal rod. The metal rod is inserted into the hollow insulating column. The metal rod is provided with an external thread that matches the insulating nut. The end of the metal rod away from the metal disk is provided with a groove that matches the signal pin. One end of the hollow insulating column is inserted into the Faraday disk shielding tube, and the other end isolates and insulates the Faraday disk from the Faraday disk shielding tube. The Faraday disk shielding tube is provided with an air hole, and the bottom surface of the Faraday disk shielding tube is provided with a mounting groove. The metal disk can be installed in the insulating ring in front of the disk. The top surface of the insulating ring in front of the disk is provided with a protrusion that matches the mounting groove. The insulating ring in front of the disk is a hollow structure.

2. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: The metal disk is a regular shape, and its cross-sectional area is greater than or equal to the cross-sectional area of ​​the metal rod.

3. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: The metal disk includes a hexagonal metal disk, an octagonal metal disk, a gear-shaped metal disk, a circular metal disk, and a quadrilateral metal disk.

4. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: The overall cross-section of the Faraday disk is T-shaped or the end of the T-shape is stepped, and the cross-section of the hollow insulating column is T-shaped.

5. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: The diagonal opposite side / diameter of the metal disk is equal to or greater than the diameter of the large end of the hollow insulating post.

6. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: The minimum diameter of the hollow insulating column is less than or equal to the minimum diameter of the Faraday disk shielding tube.

7. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: The side length of the Faraday disk is 6-20 mm, and the diagonal length is 6.9-23.1 mm.

8. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: The inner diameter of the insulating ring in front of the disk ranges from 6.4 to 21.5 mm.

9. The device for improving the ion mobility spectrometry receiving signal according to claim 1, characterized in that: A sealing gasket is arranged between the Faraday disk and the hollow insulating column, and / or between the hollow insulating column and the Faraday disk shielding cylinder.

10. A method for improving the ion mobility spectrometry receiving signal of the device according to any one of claims 1 to 9, characterized in that: There is a gap between the inner circle of the insulating ring in front of the disk and the opposite sides of the T-shaped hexagonal Faraday disk, which serves as a channel for the uniform circulation of the floating gas flow. The effective receiving area of ​​the Faraday disk can be adjusted by adjusting the size of the inner diameter of the insulating ring in front of the disk and the size of the diagonal opposite sides / diameter of the Faraday disk.

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