Apparatus and method for improving received signal in ion mobility spectrometry

Abstract

The application relates to a device and a method for improving ion mobility spectrum receiving signals, which comprise 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, an outer thread matched with the insulating nut is arranged on the metal rod, and a signal needle groove is arranged at the end of the metal rod far from the metal disc; one end of the hollow insulating column is inserted into the Faraday disc shielding cylinder, and the other end insulates the Faraday disc from the Faraday disc shielding cylinder; a gas hole is arranged on the Faraday disc shielding cylinder, a mounting groove is arranged on the bottom surface of the Faraday disc shielding cylinder, the metal disc can be mounted in the disc front insulating ring, and a protrusion 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 insulating ring, the consistency of the end surface distance between the Faraday disc and the disc front insulating ring is ensured, and the strength, reliability and consistency of the 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 that analyzes chemical substances by ionizing gas-phase molecules with an ionization source and analyzing the differences in the migration speeds of different gas-phase ions in the same electric field. It has been widely used for rapid on-site screening and detection of explosives, drugs, and toxic agents.

[0003] In an ion mobility spectrometer, 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 placed 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 this 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 central opening, an ion grid and a second insulating spacer pad with a central opening; 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 traditional electrodes are connected together by wires or electronic components welded together, the ion receiving device of this 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, which 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 0.3-0.7 mm. This distance is very small and is controlled by an infinite position 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] Li Haiyang and others invented an ion mobility spectrometry ion signal extraction and sealing device (Patent No. ZL201210536367.6). This is a sealed Faraday disk ion current signal extraction device, comprising 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. This device achieves good sealing and reliable microcurrent signal extraction, while preventing the Faraday disk from loosening due to heating, vibration, and other factors, as well as contact with the shielding grid. However, the trapezoidal sealing insulating ferrule softens and deforms during alternating hot and cold use, causing the Faraday disk to loosen and signal fluctuations, as well as reduced sealing and air leakage.

[0007] Li Haiyang et al. invented an ion receiving device for ion mobility spectrometry (patent number ZL201110428494.X). This device is a sealed Faraday disk microcurrent signal extraction device, comprising 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 compression nut, an adapter, a Faraday disk shielding tube, and a Faraday disk insulating gasket, etc., to achieve sealed and reliable microcurrent signal extraction and prevent failure caused by factors such as vibration and heating. However, the Faraday disk, annular Faraday disk insulating gasket, shielding tube, O-ring, and insulating sealing pressure ring are tightened and fastened by a sealing nut. The connection between the above components is circular and slidable. In particular, the Faraday disk is also circular in shape. Therefore, the circular Faraday disk and the sealing nut are difficult to tighten, and are prone to loosening during use, resulting in fluctuations or even loss of the collected signal. Summary of the Invention

[0008] In response to the above technical problems, a device and method for improving the ion mobility spectrometer receiving signal are provided.

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

[0010] A device for improving the reception signal of an ion mobility spectrometer comprises 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 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 that cooperates with the insulating nut. The end of the metal rod away from the metal disk is provided with a groove that cooperates with a 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. 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 cooperates 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 entire 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 front insulating ring 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 spectrometer receiving signal. A gap is provided 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 uniform flow of floating gas. The effective receiving area of ​​the Faraday disk is adjusted by adjusting the inner diameter of the insulating ring in front of the disk and the diagonal opposite sides / diameter of the Faraday disk.

[0020] Compared with the existing technology, the present invention has the following advantages: the present invention ensures the consistency of the distance between the end faces of 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, thereby improving 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any 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 This 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 embodiment 1 of the present invention.

[0028] Figure 7 This is a structural diagram of an expanded embodiment 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 and features of the embodiments of the present invention 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 in no way 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 making 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 the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate 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, numerical expressions and numerical values ​​described in these embodiments 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 techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0035] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying 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 outline 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 herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. 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 figures. For example, if the device in the 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. Unless 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, including 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. 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 cooperates with the insulating nut. The end of the metal rod away from the metal disk is provided with a groove that cooperates with 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 disk front insulating ring, and the top surface of the disk front insulating ring is provided with a protrusion that cooperates with the mounting groove. 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 entire 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 greater than or equal to 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 provided 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 spectrometer receiving signal. A gap is provided 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 uniform flow of floating gas. The effective receiving area of ​​the Faraday disk is adjusted by adjusting the inner diameter of the insulating ring in front of the disk and the diagonal opposite sides / diameter of the Faraday disk.

[0048] As an optional embodiment, the following specifications are used: 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 T-shaped Faraday disk has a side length of 16 mm and a diagonal length of 18.5 mm, and the inner diameter of the insulating ring in front of the disk is within the range of 17.2 ± 0.8 mm;

[0050] The hexagonal T-shaped Faraday disk has a side length of 12 mm and a diagonal length of 13.9 mm. The inner diameter of the insulating ring in front of the disk is within the range of 13.0 ± 0.5 mm.

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

[0052] The hexagonal T-shaped Faraday disk has a side length of 6 mm and a diagonal length of 6.9 mm, and the inner diameter of the insulating ring in front of the disk is within the range of 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 in the figure, 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] Example 1:

[0057] The hexagonal T-shaped Faraday disk has a side length of 6-20 mm and a diagonal length of 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 migration tube temperature was room temperature, 25°C; the migration zone inner diameter was 20 mm, length was 7 cm; the high voltage was 6.7 kV; the door opening time was 50 μs; the drift gas flow rate was 0.5 L / min; the carrier gas flow rate was 0.3 L / min; the drift gas and carrier gas flow rates were aligned; the gas outlet was located in the middle of the reaction zone; and room temperature acetone was used as the dopant for analysis.

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

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

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

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

[0065] Example 2

[0066] The hexagonal T-shaped Faraday disk has a side length of 6-20 mm and a diagonal length of 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 migration tube temperature was room temperature, 25°C; the migration zone inner diameter was 16 mm, length was 7 cm; the high voltage was 6.7 kV; the door opening time was 50 μs; the drift gas flow rate was 0.5 L / min; the carrier gas flow rate was 0.3 L / min; the drift gas and carrier gas flow rates were aligned; the gas outlet was located in the middle of the reaction zone; and a room temperature acetone-butanone mixture was used as the dopant for analysis.

[0070] The hexagonal T-shaped Faraday disk has a side length of 16 mm and a diagonal length of 18.5 mm. The inner diameter of the insulating ring in front of the disk is 18 mm.

[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 resolution 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 6mm, and the inner diameter of the insulating ring in front of the disk is 16.4mm;

[0073] The migration time of acetone is 3.33 ms, with a peak height of 1.1 V. The migration time of the acetone-butanone complex is 3.52 ms, with a peak height of 2.5 V and a half-peak width of 0.09 ms. The migration time of butanone is 3.72 ms, with a peak height of 1.6 V, and a total peak height of 5.2 V. The resolution 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 T-shaped Faraday disk has a side length of 6-20 mm and a diagonal length of 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 migration tube temperature was room temperature, 25°C; the migration zone had an inner diameter of 20 mm and a length of 8 cm; the high voltage was 6.7 kV; the gate opening time was 50 μs; the drift gas flow rate was 0.5 L / min; the carrier gas flow rate was 0.3 L / min; the drift gas and carrier gas flowed in the same direction; the gas outlet was at the end of the reaction zone; and a room temperature acetone-butanone mixture was used as the dopant for analysis.

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

[0080] The migration time of acetone is 4.1 ms, peak height is 0.4 V, the migration time of acetone butanone complex is 4.4 ms, peak height is 1.4 V, half-peak width is 0.08 ms, and the migration time of butanone is 4.6 ms, peak height is 1.4 V, and the total peak height is 2.3 V. The resolution 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 T-shaped Faraday disk has a side length of 6-20 mm and a diagonal length of 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 can 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 migration tube temperature was room temperature, 30°C, the migration zone inner diameter was 20 mm, length was 8 cm, high voltage was 6.7 kV, the door opening time was 50 μs, the drift gas flow rate was 0.5 L / min, the carrier gas flow rate was 0.3 L / min, the drift gas and 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 T-shaped Faraday disk has a side length of 16 mm and a diagonal length of 18.5 mm, and the inner diameter 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 T-shaped Faraday disk has a side length of 6 mm and a diagonal length of 6.9 mm, and the inner diameter 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 air holes, the number of the air holes is 1-16, and the diameter of the air holes is 0.6-3 mm; when there are multiple air holes, they are evenly distributed on the metal disk.

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

[0095] Example 6

[0096] In this embodiment, the metal rod and the insulating nut adopt other assembly forms, specifically, as Figure 7As shown, the device includes a front-disk insulating ring and a Faraday disk. Furthermore, it also includes a metal fixing disk 8, an insulating tube 10, a metal tube 9, an insulating gasket 6, a Faraday disk shielding tube 4, and a fixing bolt 7. The Faraday disk comprises a metal disk and a metal rod. The metal rod is inserted into the metal tube, and the insulating tube is sheathed on the outside of the metal tube. The metal fixing disk has a hole in the middle for the insulating tube to pass through, and also has a hole for the fixing bolt to pass through. The inner wall of the Faraday disk shielding tube is provided with a blind hole for the fixing bolt to install. The metal fixing disk is attached to the Faraday disk shielding tube via the fixing bolt. An insulating gasket is provided between the metal fixing disk and the Faraday disk shielding tube. The metal fixing disk is disposed within the Faraday disk shielding tube. The bottom end of the Faraday disk shielding tube is provided with a slot. The top surface of the front-disk insulating ring is provided with a protrusion that matches the slot. The end of the metal fixing disk away from the Faraday disk is provided with a signal connector terminal. An air vent 11 is provided on the Faraday disk shielding tube.

[0097] Example 7

[0098] Similar to Example 6, in this embodiment, an external fixed Faraday disk for receiving ion mobility spectrometry signals includes an insulating ring in front 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 includes a metal disk and a metal rod. The metal rod is inserted into the metal cylinder. The outer surface 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 fitted 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 a fixing bolt, the metal fixed disk and the Faraday disk shielding tube are installed by the 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 slot, and the top surface of the disk front insulating ring is provided with a protrusion that matches the slot. After installation, a metal fixed disk-insulating pad-Faraday disk shielding tube-disk front insulating ring 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above 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: The Faraday disk comprises 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 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 that cooperates with the insulating nut. The end of the metal rod away from the metal disk is provided with a groove that cooperates with 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. 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 cooperates with the mounting groove. The insulating ring in front of the disk is a hollow structure. 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; The entire 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; The diameter of the metal disk is greater than or equal to the diameter of the larger diameter end of the hollow insulating column; The minimum diameter of the hollow insulating column is less than or equal to the minimum diameter of the Faraday disk shielding tube.

2. The device for improving ion mobility spectrometry reception signals 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 or a quadrilateral metal disk.

3. The device for improving ion mobility spectrometry reception signals 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.

4. 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.

5. The device for improving ion mobility spectrometry reception signals according to claim 1, characterized in that: 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.

6. A method for improving an ion mobility spectrometer receiving signal of the device according to any one of claims 1 to 5, characterized in that: There is a gap between the inner circle of the insulating ring in front of the disk and the opposite side of the T-shaped hexagonal Faraday disk, which serves as a channel for the uniform circulation of floating gas. The effective receiving area of ​​the Faraday disk can be adjusted by adjusting the inner diameter of the insulating ring in front of the disk and the diameter of the Faraday disk.

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