A high-resolution gas concentration detection device

Abstract

The application discloses a high-resolution gas concentration detection device and relates to the field of semiconductor gas concentration detection.The device comprises a light source for generating detection light, a gas chamber, a filter, a detection element and a driving assembly.The gas chamber comprises an absorption cell and two mirrors oppositely arranged at two ends of the absorption cell, and the mirrors are provided with optical windows.The filter is arranged in an optical path.The driving assembly comprises a first driving element and a second driving element.The first driving element is connected with the absorption cell and is used for driving one of the optical windows to rotate around a first direction.The second driving element is connected with one of the mirrors and is used for driving the optical window on the mirror to move along the first direction.The above scheme is used to improve the sensitivity and resolution of the detection device in the limited space of the gas chamber.

Description

Technical Field

[0001] This invention relates to the field of semiconductor gas concentration detection technology, and in particular to a high-resolution gas concentration detection device. Background Technology

[0002] In semiconductor manufacturing, vapor deposition processes such as chemical vapor deposition (CVD), metal-organic CVD, and atomic layer deposition (ALD) all require precise monitoring of reactant and byproduct gases to ensure process stability and yield. Therefore, gas detection equipment is widely used in semiconductor process chambers, piping, and environmental monitoring to perform real-time detection and concentration monitoring of reactant and byproduct gases. Currently, the industry has incorporated gas monitoring into advanced process control closed loops, requiring real-time, traceable, and synchronized detection data with process cycle time. Therefore, gas detection equipment not only needs high sensitivity but also requires fast response times and system stability to meet the high demands of complex process environments.

[0003] Currently, common gas concentration detection technologies mainly employ optical methods such as non-dispersive infrared spectroscopy, tunable diode laser absorption spectroscopy, or Fourier transform infrared spectroscopy. Existing monitoring methods mostly utilize non-dispersive infrared technology, where the gas absorptivity is directly proportional to the optical path length. Increasing the effective absorption distance increases the interaction distance between gas molecules and the laser, thus increasing the amplitude of the absorptivity function and consequently improving the system's measurement sensitivity and detection resolution. To further enhance measurement sensitivity and detection resolution, the length of the absorption cell is typically extended to increase the interaction distance between gas molecules and the detection light beam. However, this method significantly increases the cell volume, leading to a substantial increase in gas replacement time and a decrease in response speed. Simultaneously, the optical path alignment tolerance amplifies with the length, and even minor vibrations or temperature drifts in the instrument can cause optical interference and signal drift.

[0004] Therefore, how to improve the sensitivity and resolution of the detection device within a limited space has become a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a high-resolution gas concentration detection device to solve the technical problem in the prior art of difficulty in improving the sensitivity and resolution of the detection device within a limited space.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A high-resolution gas concentration detection device includes:

[0008] A light source, used to generate the detection light;

[0009] The gas chamber includes an absorption cell and two reflectors disposed opposite to each other at both ends of the absorption cell, and the reflectors are provided with optical windows;

[0010] A filter element, disposed in the optical path, is used to perform spectral filtering on the optical signal after it passes through the air chamber;

[0011] A detection element is used to receive optical signals passed through the filter element and convert them into electrical signals;

[0012] A driving assembly, comprising a first driving member and a second driving member, wherein the first driving member is connected to the absorption cell and is used to drive one of the optical windows to rotate about a first direction, and the second driving member is connected to one of the reflectors and is used to drive the optical window on the reflector to move along the first direction;

[0013] The first driving member drives the optical window to rotate to change the incident or exit position of the detection light in the absorption cell, and the second driving member drives the reflector to move along the first direction to change the gas to be detected in the gas chamber from the diffusion state to the detection state.

[0014] Furthermore, the absorption cell includes:

[0015] The first cylinder and the second cylinder, wherein the first direction is the direction of the central axis of the first cylinder and the second cylinder;

[0016] A reflector is sealed at one end of the first cylinder and the second cylinder;

[0017] The first cylinder and the second cylinder are connected at their ends away from the reflector via a rotating connection, and a dynamic sealing structure is provided outside the rotating connection. The output end of the first drive member is connected to the first cylinder or the second cylinder to drive it to rotate around the central axis.

[0018] By adopting the above scheme, and introducing a rotatable connection and dynamic sealing structure at the end of the cylinder, the optical window can rotate stably while maintaining airtightness. This ensures that the transmission of the detection light under different incident / exit paths is not affected by leakage or optical path deviation. This not only guarantees the stability of gas concentration measurement but also makes optical path adjustment more flexible, thereby effectively improving the resolution and sensitivity of the detection.

[0019] Furthermore, the reflector includes a lens unit disposed at the ends of the first cylinder and the second cylinder, the lens unit having a reflective film coated on its surface facing the inside of the absorption cell, and the optical window being a light-transmitting area opened on the reflective film.

[0020] By adopting the above scheme, a reflective film is formed on the inner surface of the lens unit and a light-transmitting area is set only locally, so that the detection light beam can accurately pass through the selected area with high reflection efficiency, effectively reducing stray light and reflection loss, improving the quality of the light signal, thereby enhancing the contrast between the detection signal and the gas absorption characteristics, and thus improving the system's detection resolution and low-concentration detection sensitivity.

[0021] Furthermore, the lens unit includes a lens body and a light-blocking component arranged coaxially. The lens body has at least two optical windows, and the at least two optical windows are at different straight-line distances from the central axis of the lens body. The light-blocking component is used to select and block the optical windows.

[0022] By employing the above scheme, multiple optical windows at different positions are set on the lens body and switched by a light-sealing component, allowing for changes in the light exit or entrance positions. This alters the number of reflections and the reflection angle of the light within the absorption cell, thereby changing the effective optical path for gas absorption. By selectively changing the beam's transmission path within the gas chamber, the detection device can flexibly adapt to different gas concentration scenarios, enhancing overall sensitivity and resolution.

[0023] Furthermore, the light-blocking element includes a light-shielding sheet, and at least two optical windows include a first window and a second window, wherein the light-shielding sheet can selectively cover the first window or the second window by rotating about the central axis.

[0024] The above scheme achieves window switching through a light-shielding plate, which has the advantages of simple structure, rapid switching and high positioning accuracy, and avoids optical path deviation caused by complex mechanisms.

[0025] Furthermore, the dynamic sealing structure includes a magnetic fluid sealing assembly disposed at the rotating connection portion, the magnetic fluid sealing assembly comprising: a magnetic ring fixed to the end of the first cylinder; a magnetic pole ring fixed to the end of the second cylinder and coaxially disposed with the magnetic ring; and magnetic fluid filling the gap between the magnetic ring and the magnetic pole ring;

[0026] A magnetic field is formed between the magnetic ring and the magnetic pole ring, and the magnetic fluid forms a dynamic sealing layer in the gap under the action of the magnetic field.

[0027] Using the above scheme, the magnetofluid forms a sealing layer that can adaptively adjust with rotation under the action of the magnetic field, ensuring that the absorption pool can maintain high airtightness during the rotation adjustment process and avoiding gas leakage.

[0028] Furthermore, the first driving component includes a stepper motor and a connecting block, wherein the output shaft of the stepper motor is connected to the absorption pool via the connecting block.

[0029] Furthermore, the second driving component includes a linear motor, a first magnetic block, and a second magnetic block. The first magnetic block is fixedly connected to the reflector and slidably connected to the inner wall of the absorption tank. The second magnetic block is slidably connected to the outer wall of the absorption tank. The first magnetic block and the second magnetic block are magnetically connected, and the mover of the linear motor is connected to the second magnetic block.

[0030] Using the above scheme, the linear motor achieves non-contact drive through the magnetic connection of the magnetic blocks, improving sealing and reducing positioning errors and vibrations caused by traditional mechanical sliding friction, enabling the reflector to move smoothly and accurately. This structure not only improves the smoothness of optical path adjustment but also generates a pumping effect during the reflector's movement, converting the gas to be detected in the gas chamber from a diffusion state to a detection state, thereby improving the detection response speed and the detection sensitivity for low-concentration gases.

[0031] Furthermore, the filter element includes a filter array and a deflector. The filter array includes multiple filters whose deflection angles can be changed independently. The deflector can drive and adjust the tilt direction of the multiple filters.

[0032] Using the above scheme, multiple filters can be independently adjusted in angle to achieve selective transmission of detection light of different wavelengths, thereby effectively matching the absorption spectra of various gases. This design improves the resolution and interference suppression capabilities of specific spectral lines, enhancing the system's multi-component detection sensitivity and resolution.

[0033] Furthermore, the filter is hinged to a pivot, and the driving member is used to drive the pivot to swing.

[0034] The beneficial effects of the high-resolution gas concentration detection device provided by this invention are as follows: by introducing the synergistic effect of a first driving element and a second driving element within the gas chamber, it overcomes the limitation of existing technologies that rely solely on extending the length of the absorption cell to improve sensitivity and resolution. Specifically, the first driving element, by driving the optical window to rotate, can change the incident or exit position of the detection light within the absorption cell, thereby effectively adjusting the optical path. The second driving element drives the reflector to move horizontally, which not only further changes the effective optical path but also creates a pumping effect within the gas chamber, accelerating the transition of the gas to be measured from a diffusion state to a detection state. Thus, this invention simultaneously achieves optical path extension and improved gas exchange efficiency under limited space conditions, significantly improving the system's detection sensitivity and resolution, and avoiding problems such as excessively large cell volume, decreased response speed, and enhanced optical interference caused by traditional extended absorption cells. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a high-resolution gas concentration detection device according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the air chamber structure according to an embodiment of the present invention;

[0037] Figure 3 This is a cross-sectional view of the air chamber in an embodiment of the present invention;

[0038] Figure 4 for Figure 3 Enlarged view of point A;

[0039] Figure 5 for Figure 3 Enlarged view of point B;

[0040] Figure 6 This is a schematic diagram of the structure of the light-shielding sheet according to an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of the light reflection state inside the air chamber according to an embodiment of the present invention.

[0042] Reference numerals: 1. Light source; 2. Gas chamber; 21. First cylinder; 22. Second cylinder; 221. Rotating connection; 23. Reflector; 231. Lens body; 232. Light sealing component; 233. Sealed lens; 24. Optical window; 3. Filter component; 4. Detection component; 5. Drive assembly; 51. First drive component; 52. Second drive component; 521. Linear motor; 522. First magnetic block; 523. Second magnetic block; 6. Dynamic sealing structure; 61. Magnetic ring; 62. Magnetic pole ring; 7. Controller. Detailed Implementation

[0043] To make the objectives, 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. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0044] The following is in conjunction with the appendix Figure 1 - Appendix Figure 7 The specific embodiments of the present invention will be further described in detail below.

[0045] Reference Figures 1-2A high-resolution gas concentration detection device includes a light source 1, a gas chamber 2, a filter 3, a detector 4, and a driving assembly 5. The light source 1 generates detection light; in this embodiment, the light source 1 is preferably a broadband far-infrared light source with an output wavelength range covering 2μm to 17μm to adapt to the absorption bands of various gases and achieve high-sensitivity detection. The gas chamber 2 contains the gas to be detected and serves as the propagation cavity for the detection light. The filter 3 is disposed on the light-emitting side of the gas chamber 2 and is used to perform spectral filtering on the light signal after passing through the gas chamber 2 to select signal light of a specific wavelength. The detector 4 is disposed after the filter 3 and is used to receive the filtered light signal and convert it into an electrical signal for subsequent signal processing and concentration calculation. The driving assembly 5 includes a first driving element 51 and a second driving element 52, which are used to adjust the spatial positions of the optical window 24 and the reflector 23, respectively, to achieve dynamic adjustment of the optical path and gas state. The detector 4 is connected to a tuning amplifier circuit to amplify and transmit the signal. The detector 4 is electrically connected to a controller 7, which receives the amplified electrical signal. In some other embodiments of the present invention, the light source 1 is connected to the controller 7, and the controller 7 is capable of controlling the wavelength coverage range of the light source 1.

[0046] In some specific embodiments of the present invention, the gas chamber 2 includes an absorption cell and two reflectors 23 disposed opposite to each other at both ends of the absorption cell. (See reference...) Figure 7 An optical path cavity is formed inside the absorption cell, allowing the detection light to pass through the gas to be measured after multiple reflections. To ensure high light reflection efficiency, both reflectors 23 are coated with a high-reflectivity reflective film on their surfaces facing the inside of the absorption cell, and a light-transmitting area is opened on the reflective film as an optical window 24. The gas chamber 2 has an air inlet and an air outlet.

[0047] In some embodiments of the present invention, a first driving member 51 is connected to an absorption cell and is used to drive one of the optical windows 24 to rotate about a first direction. A second driving member 52 is connected to one of the reflectors 23 and is used to drive the optical window 24 on the reflector 23 to move along the first direction. The first driving member 51 drives the optical window 24 to rotate, thereby changing the incident or exit position of the detection light in the absorption cell. When the second driving member 52 drives the reflector 23 to move along the first direction, it converts the gas to be detected in the gas chamber 2 from a diffusion state to a detection state.

[0048] The main working principle of this invention is as follows: When measuring gas concentration using the spectral absorption method, Beer-Lambert's law applies:

[0049]

[0050] In the above formula Absorbance is a dimensionless measure of the degree to which a gas absorbs light. The intensity of the incident light. The intensity of the emitted light. is a characteristic constant of the substance, representing the absorption capacity of the gas to be measured for light of a specific wavelength, and is a constant; C is the concentration of the gas to be measured, and L is the effective optical path length of gas cell 2. Absorbance is related to both the concentration of the gas to be measured and the effective optical path length. The greater the effective optical path length of gas cell 2, the higher the detection resolution of the gas concentration. Therefore, through the structure of gas cell 2 described above, the detection light can be reflected multiple times along a preset path within the absorption cell, increasing the effective optical path and thus improving the detection resolution.

[0051] Reference Figures 3-5 In some embodiments of the present invention, the absorption cell includes a first cylinder 21 and a second cylinder 22, with the first direction being the direction of the central axis of the two cylinders. Reflectors 23 are respectively installed at the opposite ends of the first cylinder 21 and the second cylinder 22 to seal the absorption cell and ensure collimated transmission of light. The first cylinder 21 and the second cylinder 22 are connected at the ends away from the reflectors 23 via a rotating connection 221. A dynamic sealing structure 6 is provided outside the rotating connection 221 to maintain airtightness while allowing the first cylinder 21 and the second cylinder 22 to rotate relative to each other. In some embodiments, an air inlet and an air outlet are respectively provided on the first cylinder 21 and the second cylinder 22. The output end of the first driving member 51 is connected to the first cylinder 21 or the second cylinder 22 to drive the cylinder to rotate around its central axis. Through the structural design of the first cylinder 21 and the second cylinder 22, the optical window 24 can achieve stable rotation while maintaining a seal, thereby changing the incident or exit angle of light and adjusting the optical path distribution and effective optical path of the detection light within the absorption cell.

[0052] In some embodiments of the present invention, the first cylindrical body 21 and the second cylindrical body 22 have annular cross-sections, and the axial direction of the first cylindrical body is a first direction. In some embodiments of the present invention, the second cylindrical body 22 extends axially at one end near the first cylindrical body 21 to form a cylindrical rotating connecting portion 221. The first cylindrical body 21 has an annular groove at a position corresponding to the rotating connecting portion 221, and the rotating connecting portion 221 is inserted into the annular groove and achieves relative rotation.

[0053] Reference Figure 5In some specific embodiments of the present invention, the dynamic sealing structure 6 is preferably a magnetohydrodynamic (MHD) sealing assembly. The MHD sealing assembly includes a magnetic ring 61 fixed to the end of the first cylinder 21, a magnetically conductive pole ring 62 fixed to the end of the second cylinder 22 and coaxially arranged with the magnetic ring 61, and a magnetohydrodynamic fluid filling the gap between them. The magnetic ring 61 and the magnetically conductive pole ring 62 form a magnetic field, causing the magnetohydrodynamic fluid to form a continuous sealing layer under the action of the magnetic field. When the first cylinder 21 and the second cylinder 22 rotate relative to each other, the magnetohydrodynamic fluid can flow dynamically under the constraint of the magnetic field, achieving a low-friction dynamic seal. This solution not only avoids the problems of easy wear and leakage of traditional mechanical seals, but also ensures the airtight stability of the system during optical path adjustment, thereby improving detection accuracy and reliability. Furthermore, to prevent the magnetohydrodynamic fluid from entering the gas chamber 2, the MHD sealing assembly defines an annular sealing cavity at the gap between the magnetic ring 61 and the magnetically conductive pole ring 62. The sealed cavity is defined by the end face of the pole ring and the sealing retaining ring. Its structure, verified by finite element simulation, can withstand a pressure difference of at least 50 kPa and maintain its sealing performance over a long period. The magnetic fluid only fills the sealed cavity and is confined within the magnetic pole gap region under the influence of the magnetic field, forming a stable liquid sealing layer that does not directly contact the gas to be tested inside the gas chamber. The depth-to-width ratio of the sealed cavity is controlled within the range of 1:1 to 1:1.5 to ensure that the magnetic fluid is neither thrown out during rotation nor disturbed and leaked due to shear force. Tests show that within a pressure difference range of -0.08 MPa to 0.1 MPa, no detectable leakage occurred at the magnetic fluid sealing interface, meeting the airtightness requirements for high-sensitivity spectral detection. The magnetic fluid maintains a dynamic seal without being drawn in or diffused into the interior of gas chamber 2, thus avoiding contamination of the gas detection environment. In addition, both the magnetic ring 61 and the magnetic pole ring 62 are made of soft magnetic alloy materials with excellent machinability, such as permalloy or iron-nickel alloy. They have high magnetic permeability and good corrosion resistance. They can be processed by conventional precision turning or wire cutting to obtain a high coaxiality structure, thereby ensuring uniform magnetic field distribution and smooth rotation.

[0054] In some specific embodiments of the present invention, the first driving component 51 is a stepper motor. The output shaft of the stepper motor is connected to the absorption cell via a connecting block, thereby enabling precise control of the rotation angle of the optical window 24. The connecting block is made of insulating non-magnetic material, such as PEEK or anodized aluminum alloy, to prevent the magnetic field of the driving component from interfering with the magnetohydrodynamic sealing area. The stepper motor drives the rotation of the absorption cell, causing the incident or exit position of the light beam to change along the circumference of the cylinder, thereby effectively adjusting the optical path length without changing the length of the gas chamber 2, achieving dynamic optimization of optical resolution. The motor adopts a micro-step control method, with a minimum angular resolution better than 0.05°, ensuring the accuracy of optical path switching. The stepper motor drives the rotation of the absorption cell, causing the incident or exit position of the light beam to change along the circumference of the cylinder, thereby effectively adjusting the optical path length without changing the length of the gas chamber 2.

[0055] In some specific embodiments of the present invention, the second driving component 52 includes a linear motor 521, a first magnetic block 522, and a second magnetic block 523. The first magnetic block 522 is fixedly connected to the reflector 23 and slidably mounted on the inner wall of the absorption tank; the second magnetic block 523 is slidably connected to the outer wall of the absorption tank, and the first magnetic block 522 and the second magnetic block 523 are attracted by magnetic force. The mover of the linear motor 521 is connected to the second magnetic block 523. When the linear motor 521 drives the second magnetic block 523 to move, the first magnetic block 522 and the reflector 23 move accordingly, thereby realizing the non-contact translation of the reflector 23 along the central axis. The first magnetic block 522 and the second magnetic block 523 transmit driving force through magnetic coupling, avoiding the airtightness damage and friction error caused by traditional mechanical push rods. The magnetic coupling structure of the first magnetic block 522 and the second magnetic block 523 transmits driving force through the vacuum isolation cylinder wall, without mechanical through-shaft or push rod structures, thereby completely avoiding seal damage. The wall thickness is controlled between 1.0 and 2.0 mm to balance mechanical and airtight strength with magnetic flux penetration efficiency.

[0056] When the reflector 23 moves, it can induce a local pressure change in the gas within the absorption cell, thereby generating a pumping effect that rapidly transitions the gas from a diffusion state to a detection state, improving the detection response speed and the detection sensitivity for low-concentration gases. Furthermore, to prevent airflow disturbances caused by the movement of the reflector 23 from affecting the optical path, the movement speed of the reflector 23 is limited to within 10 mm / s by the controller, and transient pressure fluctuations are eliminated through gradual start-stop control.

[0057] In some specific embodiments of the present invention, the reflector 23 further includes a lens unit. The lens unit consists of a lens body 231 and a light-sealing component 232 arranged coaxially. The surface of the lens body 231 is coated with a reflective film, and at least two circular optical windows 24 are provided only in certain areas. The lens body 231 has a first window and a second window for light transmission, and the two optical windows 24 are radially distanced from the central axis. The light-sealing component 232 is used to selectively block one of the windows to change the incident or exit position of the detection light. The window opening position is determined by optical path tracing design to ensure that the light beam uniformly covers the effective area of ​​the absorption cell after reflection, avoiding spot shift during multiple reflections. When different windows are selected, the incident angle and the number of reflection paths of the detection light change accordingly, thereby changing the effective optical path, and thus enabling multi-path switching without replacing the reflector 23. An O-ring is used for static sealing between the light-sealing component 232 and the reflector 23 to prevent gas from seeping into the mounting gap of the reflector 23. A sealing lens 233 is fixedly installed at the right end of the second cylinder 22 for gas sealing and to allow light to pass through.

[0058] Reference Figure 6In some embodiments of the present invention, the light-blocking component 232 is a light-shielding plate that rotates around a central axis. The light path switching is achieved by driving the light-shielding plate to rotate to cover or open different windows. In some specific embodiments of the present invention, the light-shielding plate is fixed on a rotating shaft, which is supported on the frame of the lens unit by bearings. One end of the rotating shaft is embedded with an inner magnet (such as a neodymium iron boron permanent magnet), which is sealed inside the air chamber 2. An outer magnetic ring is installed at a corresponding position on the outside of the air chamber 2, aligned with the inner magnet, and the two are isolated by the first cylinder 21 or the wall of the first cylinder 21. The outer magnetic ring is connected to a third driving component, such as a micro stepper motor or a servo motor, which controls the rotation of the outer magnetic ring. When the external motor drives the outer magnetic ring to rotate, the inner magnet synchronously drives the light-shielding plate to rotate through magnetic coupling. Furthermore, the first cylinder 21 or the second cylinder 22 is made of a non-magnetic material to ensure magnetic field penetration while maintaining airtightness. By precisely controlling the rotation angle of the light-shielding plate with a motor, the light-shielding plate covers the first window or the second window, switching the light path mode. The thickness of the light-shielding sheet is controlled between 0.2 and 0.5 mm, and it is made of lightweight, high-temperature resistant material to ensure long-term operational stability.

[0059] In some specific embodiments of the present invention, the filter element 3 includes a filter array and a deflector. The filter array contains multiple independently adjustable filter elements (not shown in the figure), each hinged to a pivot. The deflector drives the pivot to swing, thereby changing the tilt angle of the filter element relative to the incident light, achieving selective transmission over different wavelength ranges. By independently controlling the angle of each filter element, simultaneous detection of multiple gas components can be achieved. Using the above scheme, the detection device can simultaneously perform broadband detection and high-resolution analysis in a single system, improving the detection range.

[0060] The working principle of the high-resolution gas concentration detection device provided by this invention is as follows: The first driving component 51 drives the optical window 24 in the absorption cell to rotate around the central axis, thereby changing the incident or exit angle of the detection light. Since the light forms a multi-path light due to reflection by multiple reflectors 23 in the absorption cell, the reflection path of the detection light is adjusted accordingly when the angle of the optical window 24 changes, thus changing the effective propagation length in the gas chamber 2. The dynamic change of the effective optical path can directly change the light absorption depth, enabling the system to achieve higher detection resolution with the same structural dimensions. The optical path adjustment process is carried out in a completely sealed state. The magnetohydrodynamic sealing assembly can ensure that there is no leakage or pressure fluctuation inside the gas chamber 2 when the cylinder rotates, ensuring a stable testing environment. The second driving component 52 is used to drive the reflector 23 set at the end of the absorption cell to move precisely in a straight line along the central axis. When the reflector 23 is moved back and forth under the drive of the second driving component 52, the effective volume and optical path distribution inside the absorption cell are finely adjusted, and the local pressure of the gas in the gas chamber 2 changes. Pressure changes create a weak pumping effect within a short time, causing the gas to be measured to quickly transition from a free diffusion state to a stable distribution detection state. This makes the gas concentration more uniform within the optical path cross-section, significantly shortening the system's steady-state response time. When the two driving components operate in tandem, the first driving component 51 adjusts the optical path, while the second driving component 52 synchronously adjusts the gas distribution. Through the synchronous control of the two driving components by the control unit, optimal optical path configuration and gas state switching can be achieved according to different gas types and concentration ranges. Therefore, this invention overcomes the limitation of existing technologies that rely solely on extending the absorption cell length to improve detection sensitivity. It achieves dual enhancements in optical path adjustment and gas exchange within a limited structural size, balancing structural compactness, airtightness, and detection efficiency.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0063] The above description is merely a specific implementation of the embodiments of the present invention, but the protection scope of the embodiments of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of the present invention should be covered within the protection scope of the embodiments of the present invention. Therefore, the protection scope of the embodiments of the present invention should be determined by the protection scope of the claims.

Claims

1. A high-resolution gas concentration detection device, characterized in that, include: Light source (1), used to generate detection light; The gas chamber (2) includes an absorption cell and two reflectors (23) disposed opposite to each other at both ends of the absorption cell. The reflectors (23) are provided with optical windows (24). The filter (3) is disposed in the optical path and is used to perform spectral filtering on the optical signal after passing through the air chamber (2); The detection element (4) is used to receive the optical signal passed through the filter element (3) and convert it into an electrical signal; The driving component (5) includes a first driving member (51) and a second driving member (52). The first driving member (51) is connected to the absorption cell and is used to drive one of the optical windows (24) to rotate around a first direction. The second driving member (52) is connected to one of the reflectors (23) and is used to drive the optical window (24) on the reflector (23) to move along the first direction. Wherein, the first driving member (51) drives the optical window (24) to rotate to change the incident or exit position of the detection light in the absorption cell, and the second driving member (52) drives the reflector (23) to move along the first direction to change the gas to be detected in the gas chamber (2) from the diffusion state to the detection state. The absorption cell includes: The first cylinder (21) and the second cylinder (22) are in the direction of the central axis of the first cylinder (21) and the second cylinder (22); A reflector (23) is sealed at one end of the first cylinder (21) and the second cylinder (22); The first cylinder (21) and the second cylinder (22) are connected at their ends away from the reflector (23) by a rotating connection (221), and a dynamic sealing structure (6) is provided outside the rotating connection (221); the output end of the first driving member (51) is connected to the first cylinder (21) or the second cylinder (22) to drive it to rotate around the central axis; the reflector (23) includes a lens unit disposed at the end of the first cylinder (21) and the second cylinder (22), the lens unit includes a lens body (231) and a light-blocking member (232) disposed coaxially, the lens body (231) has at least two optical windows (24), the at least two optical windows (24) are at different linear distances from the central axis of the lens body, and the light-blocking member (232) is used to select and block the optical windows (24).

2. The high-resolution gas concentration detection device according to claim 1, characterized in that, The lens unit has a reflective film coated on its surface facing the inside of the absorption cell, and the optical window (24) is a light-transmitting area opened on the reflective film.

3. The high-resolution gas concentration detection device according to claim 1, characterized in that, The light-blocking element (232) includes a light-shielding sheet, and at least two of the optical windows (24) include a first window and a second window, the light-shielding sheet being rotated about the central axis to selectively cover the first window or the second window.

4. The high-resolution gas concentration detection device according to claim 1, characterized in that, The dynamic sealing structure (6) includes a magnetic fluid sealing assembly disposed on the rotating connection part (221). The magnetic fluid sealing assembly includes: a magnetic ring (61) fixed to the end of the first cylinder (21); a magnetic pole ring (62) fixed to the end of the second cylinder (22) and coaxially disposed with the magnetic ring (61); and magnetic fluid filling the gap between the magnetic ring (61) and the magnetic pole ring (62). A magnetic field is formed between the magnetic ring (61) and the magnetic pole ring (62), and the magnetic fluid forms a dynamic sealing layer in the gap under the action of the magnetic field.

5. The high-resolution gas concentration detection device according to claim 1, characterized in that, The first driving component (51) includes a stepper motor and a connecting block, wherein the output shaft of the stepper motor is connected to the absorption pool through the connecting block.

6. The high-resolution gas concentration detection device according to claim 1, characterized in that, The second driving component (52) includes a linear motor (521), a first magnetic block (522) and a second magnetic block (523). The first magnetic block (522) is fixedly connected to the reflector (23). The first magnetic block (522) is slidably connected to the inner wall of the absorption pool. The second magnetic block (523) is slidably connected to the outer wall of the absorption pool. The first magnetic block (522) and the second magnetic block (523) are magnetically connected. The mover of the linear motor (521) is connected to the second magnetic block (523).

7. The high-resolution gas concentration detection device according to claim 1, characterized in that, The filter element (3) includes a filter array and a deflector. The filter array includes multiple filters whose deflection angle can be changed independently. The deflector can drive and adjust the tilt direction of the multiple filters.

8. A high-resolution gas concentration detection device according to claim 7, characterized in that, The filter is hinged to a pivot, and the driving element is used to drive the pivot to swing.

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