An assembly and method for improving the degree of coincidence of tp ion gates in ion mobility spectrometry

Abstract

The present application relates to the technical field of ion mobility spectrometry, and particularly relates to a component and method for improving the coincidence degree of TP ion gate in ion mobility spectrometry. The component comprises three insulating sheets, two grid sheets and a plurality of fasteners; the insulating sheet comprises a circular ring structure with a circular through hole I in the center; the grid sheet comprises a circular main body and a grid, wherein the circular main body is an annular structure with a circular through hole II in the center, and the grid is arranged in the circular through hole II of the circular main body; the insulating sheet and the grid sheet are alternately stacked in sequence, and the two grid sheets are kept coincident, and the stacked insulating sheet and grid sheet are positioned and locked by the plurality of fasteners to form a coaxial assembly structure. The present application has simple structure, controllable cost, significantly improved coincidence degree of the two grid sheets, improved performance of ion mobility spectrometry, and is suitable for mass production.

Description

Technical Field

[0001] This invention relates to the field of ion mobility spectrometry, and specifically to a component and method for improving the overlap of TP ion gates in ion mobility spectrometry. Background Technology

[0002] Ion mobility spectrometry (IMS) is an analytical technique that separates and detects different ions based on the differences in their mobility in an electric field at atmospheric or near-atmospheric pressure. It has advantages such as fast response, high sensitivity, and portability.

[0003] The Tyndall-Powell (TP) gate is a core component of ion mobility spectrometry (IMS), used to control the timing of ions entering the migration region. A typical TP gate consists of two parallel metal grids spaced at a certain distance, with an insulating layer between them. During operation, the "on" or "off" of the ion beam is controlled by applying electric fields in different directions between the two grids. The overlap of the TP gate (i.e., the relative positional accuracy of the two grid wires) directly determines the sensitivity and resolution of the IMS. Existing split-layer stacked structures of TP gates lack precise positioning references, angle correction, and detection feedback structures, making it impossible to actively control and quantitatively evaluate the overlap of the two grids. Accumulated tolerances easily lead to poor product consistency and insufficient thermal stability, thus limiting the improvement of IMS sensitivity and resolution.

[0004] Current TP ion gates typically employ a split-assembly process: two independent metal grids are fabricated first, and then stacked and fixed together with an insulating sheet. This process has the following drawbacks:

[0005] 1. Lacking precise positioning benchmarks, assembly relies mainly on visual inspection, making it difficult to guarantee the overlap between the two grid pieces, and especially difficult to control the rotation angle deviation.

[0006] 2. Insufficient understanding of the tolerance for the two types of deviations: Translation deviation (misalignment) mainly leads to a decrease in signal strength, while angular deviation (rotation) severely damages both signal strength and resolution, and is the most critical factor affecting performance.

[0007] 3. Accumulated tolerances lead to poor product consistency and insufficient thermal stability.

[0008] Therefore, there is an urgent need for a component and method that can effectively improve the overlap of TP ion gates. Summary of the Invention

[0009] To address the aforementioned problems, the present invention aims to provide a component and method for improving the overlap of TP ion gates in ion mobility spectra, thereby solving the problems of lack of precise positioning reference between two grids, difficulty in controlling translational and angular deviations, and poor product consistency in existing assembly processes.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] The present invention provides a component for improving the TP ion gate coincidence in ion mobility spectra, comprising three insulating sheets, two grid sheets and several fasteners;

[0012] The insulating sheet includes an annular body, which is a circular structure with a central circular through hole I;

[0013] The grid sheet includes a circular body and a grid, wherein the circular body has a circular through hole II at its center, and the grid is disposed in the circular through hole II of the circular body;

[0014] The insulating sheet and the grid sheet are stacked alternately in sequence, with the two grid sheets overlapping. The stacked insulating sheet and grid sheet are positioned and locked by a number of fasteners to form a coaxial assembly structure.

[0015] The insulating sheet also includes an upper connecting seat I disposed above the annular body. The upper connecting seat I has a rectangular structure and is provided with an upper circular mounting hole I.

[0016] The grid sheet also includes an upper connecting seat II disposed above the circular main body. The upper connecting seat II has a rectangular structure and is provided with an upper circular mounting hole II. The upper circular mounting hole II on the grid sheet corresponds one-to-one with the upper circular mounting hole I on the insulating sheet so that the fastener can pass through.

[0017] The grid sheet also includes an upper connecting handle disposed on the upper connecting seat II, the upper connecting handle being used to drive the grid sheet to rotate.

[0018] The insulating sheet also includes a lower connecting seat I disposed below the annular body. The lower connecting seat I has a rectangular structure and is provided with a lower circular mounting hole I.

[0019] The grid sheet also includes a lower connecting seat II disposed below the circular main body. The lower connecting seat II has a rectangular structure and is provided with a lower circular mounting hole II. The lower circular mounting hole II of the grid sheet corresponds one-to-one with the lower circular mounting hole I on the insulating sheet so that the fastener can pass through.

[0020] The upper connecting seat I, the annular body, and the lower connecting seat I are an integral structure; the upper connecting handle, the upper connecting seat II, the circular body, and the lower connecting seat II are an integral structure.

[0021] The number of upper circular mounting holes I and lower circular mounting holes I on the insulating sheet and the number of the grid sheet

[0022] The fasteners include PEEK screws and nuts. The PEEK screws pass through the corresponding circular mounting holes on the insulating sheet and the grid sheet in sequence and are then locked in place by the nuts.

[0023] The upper circular mounting hole I and lower circular mounting hole I on the insulating sheet and the upper circular mounting hole II and lower circular mounting hole II on the grid sheet have the same diameter, and the difference between them and the outer diameter of the PEEK screw is 0.1 to 0.22 mm; after assembly, the maximum translational deviation between the two grid sheets is not greater than 0.11 mm, and the maximum angular deviation is not greater than 2.10°.

[0024] The mesh is made of stainless steel and is a square grid woven from mesh strips; the insulating sheet is made of PEEK.

[0025] Another aspect of the present invention provides a method for improving the TP ion gate overlap in ion mobility spectra based on the components described above, comprising the following steps:

[0026] Step 1: Prepare three insulating sheets, two grid sheets, and several fasteners, including PEEK screws and nuts;

[0027] Step 2: Arrange the three insulating sheets and two grid sheets in a sandwich-like parallel manner in the order of insulating sheet, grid sheet, insulating sheet, grid sheet, insulating sheet, so that the circular mounting holes on each layer are coaxially aligned;

[0028] Step 3: Pass the PEEK screws through the coaxially aligned circular mounting holes of each layer, and tighten them with nuts to form a coaxial assembly structure;

[0029] Step 4: Observe the overlap of the grids on the two grid sheets using optical inspection equipment, including measuring the maximum translational deviation and the maximum angular deviation;

[0030] Step 5: Based on the test results, fine-tune the relative positions of the two grid panels until the maximum translational deviation and the maximum angular deviation are both less than the preset threshold.

[0031] Step 6: Tighten the PEEK screws and nuts to complete the fixed assembly of the TP ion gate assembly.

[0032] In step four, the maximum translational deviation δ_max is measured as follows: select vertex A on the edge of the upper grid, find the theoretical corresponding vertex A' on the lower grid, measure the horizontal vertical deviation Δx and the vertical deviation Δy between vertex A and vertex A', and take the maximum translational deviation δ_max = max(|Δx|, |Δy|).

[0033] The maximum angular deviation θ_max is measured as follows: Select two vertices A1 and A2 that are far apart on the upper grid, find the corresponding vertices A1' and A2' on the lower grid, and calculate the angle between vectors A1A2 and A1'A2'. This angle is the maximum angular deviation θ_max.

[0034] The present invention has the following beneficial effects and advantages:

[0035] 1. Significantly improves overlap: Through precise assembly hole diameter and reasonable center distance design, combined with the assembly method of pre-tightening-inspection-fine-adjustment-locking, the maximum translational deviation is controlled within 0.11mm and the maximum angular deviation is controlled within 2.10°; even higher precision can be achieved when using M1.2 or M1.6 specifications (translational deviation ≤0.05mm, angular deviation ≤0.95°).

[0036] 2. Improve ion mobility spectrometry performance: Reducing translational deviation can decrease ion collision loss and increase signal intensity; reducing angular deviation can ensure the consistency of ion cluster implantation time, suppress peak broadening, and significantly improve resolution.

[0037] 3. Good consistency, suitable for mass production: The use of coaxial assembly structure and optical inspection equipment eliminates human error and ensures high product consistency.

[0038] 4. Simple structure and controllable cost: Standard PEEK screws are used for positioning and fastening, eliminating the need for complex tooling and making implementation easy.

[0039] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0040] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0041] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0042] Figure 1 This is an isometric view of a component for improving the TP ion gate overlap in ion mobility spectra according to the present invention.

[0043] Figure 2 This is a front view of a component for improving the TP ion gate overlap in ion mobility spectra according to the present invention.

[0044] Figure 3 This is a schematic diagram of the insulating sheet in this invention;

[0045] Figure 4 This is a schematic diagram of the structure of the grid sheet in this invention;

[0046] Figure 5 This is an isometric view of two grids with a misalignment in their overlap, as shown in an embodiment of the present invention.

[0047] Figure 6 This is a front view showing a discrepancy in the overlap between two grids in an embodiment of the present invention.

[0048] Figure 7 This is a schematic diagram of the TP ion gate angle deviation measurement method in an embodiment of the present invention;

[0049] Figure 8 This is a schematic diagram of the TP ion gate translation deviation measurement method in an embodiment of the present invention;

[0050] Figure 9 This is a graph showing the results of acetone-butanone mixture analysis at different overlap rates of TP ion gate grids in an embodiment of the present invention.

[0051] Figure 10 This is a graph showing the results of anisole analysis under different overlap degrees of TP ion-gated grids in an embodiment of the present invention.

[0052] In the diagram: 1. Insulating sheet; 2. Grid mesh sheet; 3. PEEK screw; 101. Upper circular mounting hole I; 102. Upper connecting seat I; 103. Annular body; 104. Lower connecting seat I; 105. Lower circular mounting hole I; 201. Upper connecting handle; 202. Upper circular mounting hole II; 203. Upper connecting seat II; 204. Grid mesh strip; 205. Circular body; 206. Lower connecting seat II; 207. Lower circular mounting hole II. Detailed Implementation

[0053] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0055] See Figures 1 to 4As shown, this invention provides an assembly for improving the overlap of TP ion gates in ion mobility spectra, comprising three insulating sheets 1, two grid sheets 2, and several fasteners; the insulating sheet 1 includes an annular body 103, which is a ring structure with a central circular through hole I; the grid sheet 2 includes a circular body 205 and a grid 204, wherein the circular body 205 is an annular structure with a central circular through hole II, and the grid 204 is disposed within the circular through hole II of the circular body 205; the insulating sheets 1 and grid sheets 2 are stacked alternately in sequence, and the two grid sheets 2 are kept overlapping, and the stacked insulating sheets 1 and grid sheets 2 are positioned and locked by several fasteners to form a coaxial assembly structure; thus, the error of manual visual alignment is eliminated from the structure, ensuring the parallelism and coaxiality of the two grid sheets 2.

[0056] See Figure 3 and Figure 4 As shown, the insulating sheet 1 also includes an upper connecting seat I 102 disposed above the annular body 103. The upper connecting seat I 102 has a rectangular structure and is provided with an upper circular mounting hole I 101. The grid sheet 2 also includes an upper connecting seat II 203 disposed above the circular body 205. The upper connecting seat II 203 has a rectangular structure and is provided with an upper circular mounting hole II 202. The upper circular mounting hole II 202 of the grid sheet 2 corresponds one-to-one with the upper circular mounting hole I 101 on the insulating sheet 1, and the diameters are equal, so that fasteners can pass through.

[0057] Furthermore, the grid plate 2 also includes an upper connecting handle 201 disposed on the upper connecting seat II 203. The upper connecting handle 201 is a slender straight rod and is used to drive the grid plate 2 to rotate.

[0058] Furthermore, the insulating sheet 1 also includes a lower connecting seat I 104 disposed below the annular body 103. The lower connecting seat I 104 has a rectangular structure and is provided with a lower circular mounting hole I 105. The grid sheet 2 also includes a lower connecting seat II 206 disposed below the circular body 205. The lower connecting seat II 206 has a rectangular structure and is provided with a lower circular mounting hole II 207. The lower circular mounting hole II 207 of the grid sheet 2 corresponds one-to-one with the lower circular mounting hole I 105 on the insulating sheet 1, and the diameters are equal, so that fasteners can pass through.

[0059] Preferably, the upper connecting seat I 102, the annular body 103, and the lower connecting seat I 104 are integral structures; the upper connecting handle 201, the upper connecting seat II 203, the circular body 205, and the lower connecting seat II 206 are integral structures. The inner and outer diameters of the circular body 205 and the annular body 103 are equal, and the grid is confined within the annular space of the insulating sheet, avoiding radial misalignment during assembly and providing a basic guarantee for the overlap. The number of upper circular mounting holes I 101 and lower circular mounting holes I 105 on the insulating sheet 1 and the number of upper circular mounting holes II 202 and lower circular mounting holes II 207 on the grid sheet 2 are both 1-4.

[0060] See Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the fasteners include PEEK screws 3 and nuts. The PEEK screws 3 pass through the corresponding circular mounting holes on the insulating sheet 1 and the grid sheet 2 in sequence and are then locked and fixed by the nuts.

[0061] Preferably, the material of the grid sheet 2 is stainless steel, and the grid 204 is a square mesh woven from grid strips with uniform thickness and consistent mesh size; the material of the insulating sheet 1 is PEEK.

[0062] In the embodiments of the present invention, the upper circular mounting hole I101 and the lower circular mounting hole I105 on the insulating sheet 1 and the upper circular mounting hole II202 and the lower circular mounting hole II207 on the grid sheet 2 have the same diameter, and the difference between them and the outer diameter of the PEEK screw 3 is 0.1 to 0.22 mm; after assembly, the maximum translational deviation between the two grid sheets 2 is not greater than 0.11 mm, and the maximum angular deviation is not greater than 2.10°.

[0063] Specifically, the PEEK screws 3 are selected from M1.2, M1.6, M2, M2.5, or M3 specifications, and the quantity is 2 to 8. The circular mounting holes on the insulating sheet 1 and the grid sheet 2 adopt the through hole diameter of the precision assembly series specified in GB / T 5277-1985, specifically: 1.3mm for M1.2, 1.7mm for M1.6, 2.2mm for M2, 2.7mm for M2.5, and 3.2mm for M3. In this embodiment, the upper connecting seat I102 of the insulating sheet 1 is provided with two upper circular mounting holes I101, and the lower connecting seat I104 is provided with two lower circular mounting holes I105. The two lower circular mounting holes I105 correspond one-to-one with the two upper circular mounting holes I101 in the vertical direction, and the center distance L1 of the two lower circular mounting holes I105 is 6mm to 10mm. The upper connecting seat II 203 of the grid panel 2 is provided with two upper circular mounting holes II 202, which are coaxial with the two upper circular mounting holes I 101 respectively. The lower connecting seat II 206 is provided with two lower circular mounting holes II 207, which are coaxial with the two lower circular mounting holes I 105 respectively. The center distance L2 between the two lower circular mounting holes II 207 is 6mm to 10mm. After assembly, the maximum translational deviation δ_max between the two stainless steel grid panels is not greater than 0.11mm, and the maximum angular deviation θ_max is not greater than 2.10°. When using M1.2 or M1.6 specifications, the diameter of the circular mounting holes is 1.3mm or 1.7mm; the maximum translational deviation δ_max is not greater than 0.05mm, and the maximum angular deviation θ_max is not greater than 0.95°.

[0064] This invention provides a component for improving the overlap of TP ion gates in ion mobility spectra. Both the insulating sheet and the grid sheet are integrally molded, reducing the number of parts and avoiding the cumulative tolerances caused by separate processing. The PEEK insulating sheet and the stainless steel grid sheet have a higher matching coefficient of thermal expansion, reducing structural deformation caused by temperature changes. The screws and mounting holes adopt the GB / T5277 precision assembly series, with extremely small gaps, ensuring that the grid position will not shift with temperature / vibration after locking, improving thermal stability and long-term consistency. This invention features a slender, straight connecting handle at the top of the stainless steel grid. During assembly, the grid can be rotated slightly by clamping the connecting handle, achieving active correction of angular deviations. Simultaneously, the symmetrical arrangement of multiple fasteners avoids grid tilting or secondary shifting caused by uneven force at a single point, solving the defect of traditional structures that cannot fine-tune rotational deviations and effectively controlling the angular deviation, which is the most critical factor affecting performance.

[0065] See Figures 1 to 8 As shown, another aspect of the present invention provides a method for improving the TP ion gate overlap in ion mobility spectra based on the components described above, comprising the following steps:

[0066] Step 1: Prepare three insulating sheets 1, two grid sheets 2, and several fasteners, including PEEK screws 3 and nuts;

[0067] Step 2: Arrange the three insulating sheets 1 and the two grid sheets 2 in a sandwich-like parallel manner in the order of insulating sheet 1, grid sheet 2, insulating sheet 1, grid sheet 2, and insulating sheet 1, so that the circular mounting holes on each layer are coaxially aligned.

[0068] Step 3: Pass the PEEK screws 3 through the coaxially aligned circular mounting holes of each layer, and pre-tighten them with nuts to form a coaxial assembly structure;

[0069] Step 4: Observe the overlap of the grids 204 on the two grid plates 2 using optical inspection equipment, including measuring the maximum translational deviation and the maximum angular deviation;

[0070] Step 5: Based on the test results, fine-tune the relative positions of the two grid pieces 2 until the maximum translational deviation and the maximum angular deviation are both less than the preset threshold.

[0071] Step 6: Tighten PEEK screws 3 and nuts to complete the fixed assembly of the TP ion gate assembly.

[0072] In step four, the optical inspection equipment is a flash meter or an industrial camera; the maximum translational deviation δ_max is measured as follows: vertex A is selected on the edge of the upper grid 204, and the theoretically corresponding vertex A' is found on the lower grid 204. The horizontal vertical deviation Δx and the vertical deviation Δy between vertex A and vertex A' are measured, and the maximum translational deviation δ_max = max(|Δx|, |Δy|) is taken. (See [reference]) Figure 8 As shown; the maximum angular deviation θ_max is measured as follows: On the upper-layer grid 204, select two relatively far vertices A1 and A2; on the lower-layer grid 204, find the corresponding vertices A1' and A2'; calculate the angle between vectors A1A2 and A1'A2'. This angle is the maximum angular deviation θ_max. See [link to documentation]. Figure 7 As shown.

[0073] In step five, fine-tuning is performed using a precision displacement platform or a manual fine-tuning fixture. The preset thresholds are: maximum translational deviation (δ_max) not greater than 0.11 mm, and maximum angular deviation (θ_max) not greater than 2.10°. When the PEEK screw 3 is M1.2 or M1.6, the preset thresholds are: maximum translational deviation (δ_max) not greater than 0.05 mm, and maximum angular deviation (θ_max) not greater than 0.95°.

[0074] Example 1: M1.2 PEEK screw, center distance 6mm.

[0075] Using the components described above, the PEEK screws are M1.2, the diameter of the circular mounting holes is 1.3mm (precision assembly), and the center distance L of the circular mounting holes is 6mm. Assembled according to the method of this invention, the optical inspection equipment is a flash meter.

[0076] Post-assembly measurement results (average of 10 repeated tests):

[0077] Maximum translational deviation δ_max = 0.03 mm (less than 0.05 mm);

[0078] The maximum angular deviation θ_max = 0.58° (less than 0.95°).

[0079] In this embodiment, the single-sided fitting gap is only 0.05mm, and extremely high overlap is achieved through fine-tuning.

[0080] Example 2: M1.6 PEEK screw, center distance 8mm.

[0081] The device uses an M1.6 specification, with a 1.7mm diameter circular mounting hole and a center distance L=8mm between the two circular mounting holes. An industrial camera is used in conjunction with image measurement software for inspection.

[0082] Measurement results:

[0083] δ_max = 0.04 mm;

[0084] θ_max = 0.68°.

[0085] All meet the preferred threshold requirements.

[0086] Example 3: M2 PEEK screw, center distance 9mm.

[0087] The M2 specification is adopted, the diameter of the circular mounting hole is 2.2mm, and the center distance between the two circular mounting holes is L=9mm.

[0088] Measurement results:

[0089] δ_max = 0.09 mm (not greater than 0.11 mm);

[0090] θ_max = 1.25° (not greater than 1.40°).

[0091] This demonstrates that even with larger screws, the basic overlap requirement can still be met.

[0092] Example 4: The effect of different center distances on angular deviation (M2 screw, hole diameter 2.2mm).

[0093] Fix the M2 screw, change the center distance L, and measure the angular deviation:

[0094] 6 2.09 1.85 7 1.79 1.58 8 1.57 1.36 9 1.39 1.20 10 1.26 1.08

[0095] Data shows that the larger the center distance, the smaller the angular deviation. It is recommended to use a larger center distance (8-10mm) when the structure allows.

[0096] Example 5: Batch consistency test (M1.2 screws, center distance 6mm).

[0097] After assembling 20 TP ion gate modules consecutively, the statistical results are as follows:

[0098] δ_max (mm) 0.032 0.006 0.021 0.044 θ_max (°) 0.60 0.09 0.47 0.78

[0099] All samples met the requirements of δ_max≤0.05mm and θ_max≤0.95°, demonstrating that the method of the present invention has excellent repeatability and stability.

[0100] Comparative example: Visual assembly (not the solution of this invention).

[0101] Using M2 screws, a rough assembly hole diameter of 2.6mm, and a center distance of 5mm, assembly was performed solely by visual inspection without the use of positioning structures or fine-tuning methods. Measurement results showed δ_max = 0.28mm and θ_max = 4.2°, significantly exceeding the threshold values ​​of this invention, leading to a severe degradation in ion gate performance.

[0102] Example 6: An acetone-butanone mixture was analyzed using an ion migration tube at room temperature under identical experimental conditions.

[0103] See Figure 9 As shown, the TP ion gate grid has two different degrees of overlap. The migration times from smallest to largest (from left to right) are acetone peak, acetone-butanone composite peak, and butanone peak. The solid line represents the result of high overlap, with an average angle deviation of ±0.2° and a maximum peak height of 4.0V. The dashed line represents the result of low overlap, with an average angle deviation of ±3° and a maximum peak height of 3.5V.

[0104] In terms of peak height and intensity, TP ion gates with high overlap are superior to TP ion gates with low overlap.

[0105] Example 7: Anisole gas was analyzed using an ion migration tube at 150°C under identical experimental conditions.

[0106] See Figure 10 As shown, the TP ion gate grid has two different degrees of overlap. The peak with the smallest migration time from left to right is anisole. With high overlap, the maximum angle deviation of the measuring instrument is 1° and the maximum peak height is 8.7V. With low overlap, the maximum angle deviation is 5° and the maximum peak height is 5.5V.

[0107] Judging from the intensity of the anisole peak, the TP ion gate with a high degree of overlap is superior to the TP ion gate with a low degree of overlap.

[0108] In summary, the components and methods provided by this invention can effectively improve the overlap of TP ion gates and achieve the expected technical effects.

[0109] This invention discloses a component and method for improving the coincidence of TP ion gates in ion mobility spectrometry. The component includes three PEEK insulating sheets, two stainless steel grids, and several PEEK screws and nuts. Both the insulating sheets and grids have coaxial circular mounting holes, and the three components are arranged in a sandwich-parallel configuration in the order of insulating sheet-grid-insulating sheet-grid-insulating sheet, and are secured with PEEK screws and nuts. The PEEK screws are selected from M1.2, M1.6, M2, M2.5, or M3 specifications, with 2 to 8 screws in total, and the center distance between the circular mounting holes is 6 to 10 mm. After assembly, the maximum translational deviation between the two grid sheets is no greater than 0.11 mm, and the maximum angular deviation is no greater than 2.10°. This invention significantly improves the grid coincidence through coaxial precision assembly, thereby enhancing the signal strength, resolution, and reliability of ion mobility spectrometry.

[0110] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An assembly for improving the degree of coincidence of TP ion gates in ion mobility spectrometry, characterized in that, It includes three insulating sheets, two grid sheets, and several fasteners; The insulating sheet includes an annular body, which is a circular structure with a central circular through hole I; The grid sheet includes a circular body and a grid, wherein the circular body has a circular through hole II at its center, and the grid is disposed in the circular through hole II of the circular body; The insulating sheet and the grid sheet are stacked alternately in sequence, with the two grid sheets overlapping. The stacked insulating sheet and grid sheet are positioned and locked by a number of fasteners to form a coaxial assembly structure.

2. The assembly of claim 1, wherein, The insulating sheet also includes an upper connecting seat I disposed above the annular body. The upper connecting seat I has a rectangular structure and is provided with an upper circular mounting hole I. The grid sheet also includes an upper connecting seat II disposed above the circular main body. The upper connecting seat II has a rectangular structure and is provided with an upper circular mounting hole II. The upper circular mounting hole II on the grid sheet corresponds one-to-one with the upper circular mounting hole I on the insulating sheet so that the fastener can pass through.

3. The assembly of claim 2, wherein, The grid sheet also includes an upper connecting handle disposed on the upper connecting seat II, the upper connecting handle being used to drive the grid sheet to rotate.

4. The assembly of claim 2, wherein, The insulating sheet also includes a lower connecting seat I disposed below the annular body. The lower connecting seat I has a rectangular structure and is provided with a lower circular mounting hole I. The grid sheet also includes a lower connecting seat II disposed below the circular main body. The lower connecting seat II has a rectangular structure and is provided with a lower circular mounting hole II. The lower circular mounting hole II of the grid sheet corresponds one-to-one with the lower circular mounting hole I on the insulating sheet so that the fastener can pass through.

5. The assembly of claim 4, wherein, The upper connecting seat I, the annular body, and the lower connecting seat I are an integral structure; the upper connecting handle, the upper connecting seat II, the circular body, and the lower connecting seat II are an integral structure. The number of upper circular mounting holes I and lower circular mounting holes I on the insulating sheet and the number of upper circular mounting holes II and lower circular mounting holes II on the grid sheet are both 1-4.

6. The assembly of claim 4, wherein, The fasteners include PEEK screws and nuts. The PEEK screws pass through the corresponding circular mounting holes on the insulating sheet and the grid sheet in sequence and are then locked in place by the nuts.

7. The component for improving the overlap of TP ion gates in ion mobility spectra according to claim 6, characterized in that, The upper circular mounting hole I and lower circular mounting hole I on the insulating sheet and the upper circular mounting hole II and lower circular mounting hole II on the grid sheet have the same diameter, and the difference between them and the outer diameter of the PEEK screw is 0.1 to 0.22 mm; after assembly, the maximum translational deviation between the two grid sheets is not greater than 0.11 mm, and the maximum angular deviation is not greater than 2.10°.

8. The assembly of claim 7, wherein the assembly is configured to increase the degree of TP ion gate overlap in ion mobility spectrometry. The mesh is made of stainless steel and is a square grid woven from mesh strips; the insulating sheet is made of PEEK.

9. A method for increasing the degree of coincidence of TP ion gates in ion mobility spectrometry based on the assembly of claim 8, characterized in that, Includes the following steps: Step 1: Prepare three insulating sheets, two grid sheets, and several fasteners, including PEEK screws and nuts; Step 2: Arrange the three insulating sheets and two grid sheets in a sandwich-like parallel manner in the order of insulating sheet, grid sheet, insulating sheet, grid sheet, insulating sheet, so that the circular mounting holes on each layer are coaxially aligned; Step 3: Pass the PEEK screws through the coaxially aligned circular mounting holes of each layer, and tighten them with nuts to form a coaxial assembly structure; Step 4: Observe the overlap of the grids on the two grid sheets using optical inspection equipment, including measuring the maximum translational deviation and the maximum angular deviation; Step 5: Based on the test results, fine-tune the relative positions of the two grid panels until the maximum translational deviation and the maximum angular deviation are both less than the preset threshold. Step 6: Tighten the PEEK screws and nuts to complete the fixed assembly of the TP ion gate assembly.

10. The method of claim 9, wherein the method is performed by a method comprising: In step four, the maximum translational deviation δ_max is measured as follows: select vertex A on the edge of the upper grid, find the theoretical corresponding vertex A' on the lower grid, measure the horizontal vertical deviation Δx and the vertical deviation Δy between vertex A and vertex A', and take the maximum translational deviation δ_max = max(|Δx|, |Δy|). The maximum angular deviation θ_max is measured as follows: Select two vertices A1 and A2 that are far apart on the upper grid, find the corresponding vertices A1' and A2' on the lower grid, and calculate the angle between vectors A1A2 and A1'A2'. This angle is the maximum angular deviation θ_max.

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