Arc-shaped wall chamber long light path gas sensor

Abstract

The utility model discloses an arc-shaped wall chamber long light path gas sensor which comprises a device shell, an optical chamber, a light source working circuit board, a detector working circuit board, a light source and a detector, the optical chamber is composed of an arc-shaped wall, a reflection center and a cover plate, and in the optical chamber, the reflection center is a hexagonal cylinder; the six walls and the five arc-shaped walls are combined at a certain angle to form a multi-reflection light path, a light barrier is arranged on one side of the reflection center and the arc-shaped walls to prevent light emitted by a light source from directly entering a detector, and the structure forms an integral cavity structure under the covering of the upper cavity cover plate and the lower cavity cover plate. The upper cover plate and the lower cover plate are provided with gas diffusion grids, and gas is diffused into an optical chamber of the sensor through the grids. The inner wall of the cavity is coated with a high-reflectivity thin film for the light source. According to the light path system, the light beam reaches the detector after being reflected for multiple times in the cavity, so that a very large absorption light path is achieved; the device is compact in structure, large in measuring range and high in measuring precision.

Description

Technical Field

[0001] The utility model relates to the field of sensors, in particular to a long optical path gas sensor with an arc-shaped wall chamber and an optical path space optimized in design. Background Art

[0002] A gas sensor is a gas sensing device that uses the spectral selective absorption characteristics of different gas molecules and the relationship between gas concentration and absorption intensity (Lambert-Beer law) to identify gas components and determine their concentration. A gas sensor usually consists of four parts: a light source, an optical cavity, a detector, and a signal acquisition and processing circuit. However, the spatial volume of traditional gas sensors cannot be too large, which limits the interaction between light and gas. Improvement solutions often use a broken line optical path, which requires the careful arrangement of the positions of multiple reflectors, and multiple refractions and reflections will increase light loss. The light source and detector need to be combined with the optical cavity to form a complete optical path. This structure results in a small optical cavity and an insufficiently long optical path, so that the light emitted by the light source cannot fully contact the gas, resulting in insufficient accuracy and sensitivity of the sensor. Utility Model Content

[0003] The purpose of the utility model is to provide a gas sensor device structure with a long optical path in an arc-shaped wall chamber. Through chamber optimization design, the light emitted by a light source is reflected multiple times in the chamber through a combination of an arc-shaped wall and a reflection center to reach a detector. The light emitted by the light source is received by the detector through a long optical path to realize gas measurement.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is: a curved wall chamber long light path gas sensor, including a device housing, an optical chamber, a working circuit board, and a light source and a detector respectively connected to the working circuit board.

[0005] The sensor comprises an optical chamber, which is composed of an arc-shaped wall, a reflective center and a cover plate:

[0006] The arc-shaped wall and the cover plate can be assembled into a closed overall structure; the reflection center is vertically located at the inner center of the overall structure, the height of the reflection center is consistent with the height of the arc-shaped wall, and its upper and lower ends are flush with the upper and lower cover plates respectively; the arc-shaped wall, the reflection center and the cover plate constitute a closed optical chamber of the sensor; a light source and a detector are installed on the working circuit board, and the light source and the detector are separated by a light-blocking plate in the chamber, and the light emitted by the light source reaches the detector after multiple reflections in the optical chamber.

[0007] The outer surface of the arc-shaped wall is a cylindrical structure.

[0008] The circumference of the sensor is composed of cylindrical walls. In the optical chamber, the reflection center is a hollow hexagonal cylinder. The six walls of the cylinder and the five arc walls are combined at a certain angle to complete a multi-reflection light path. The six faces of the hexagonal cylinder are reflection center wall one, reflection center wall two, reflection center wall three, reflection center wall four, reflection center wall five, and reflection center wall six; the inner surface of the arc wall is 5 arc surfaces, namely arc wall one, arc wall two, arc wall three, arc wall four, and arc wall five, and the endpoints of the 5 arc surfaces are connected to each other; the five corners of the hexagonal cylinder point to the center points of the 5 arcs respectively, and the reflection light path in the chamber is formed in this specific combination.

[0009] There is a light shield on one side of the reflection center and the arc wall to prevent the light emitted by the light source from directly entering the detector. The above structure forms an overall chamber structure under the cover of the chamber upper cover and the chamber lower cover. Specifically, a light shield is set at the sixth corner of the hexagonal column structure, and the upper and lower ends of the light shield are flush with the upper and lower covers respectively. The light source working circuit board and the detector working circuit board are respectively installed inside the hexagonal columns on both sides of the light shield. The sides of the hexagonal columns on both sides of the light shield are provided with light source mounting holes and detector mounting holes. The light source is fixed on the light source working circuit board through the light source mounting holes, and the detector is fixed on the detector working circuit board through the detector mounting holes. The light shield separates the light source and the detector.

[0010] In the optical path system, a light beam is emitted from a light source, hits an arc wall, reflects to a wall of a reflection center, and then reflects to the next arc wall, and so on until it hits a detector.

[0011] Based on the above, the light source working circuit board and the detector working circuit board are both encapsulated in the reflection hub, and the reflection hub wall 1 and the reflection hub wall 6 are provided with light source mounting holes and detector mounting holes for mounting the light source and the detector.

[0012] Based on the above, the light blocking plate is used to allow the light emitted by the light source to enter the detector with the maximum optical path.

[0013] Based on the above, the arc wall and the reflective central wall are combined at a certain angle to form a reflective light path in the chamber.

[0014] Based on the above, under the premise of satisfying the light reflection function in the chamber, the number of combinations of five curved walls and a hexagonal reflection center can be changed to expand the optical path.

[0015] Based on the above, the inner walls of the chamber are coated with a high reflectivity film for the light source.

[0016] Based on the above, a gas diffusion grid is provided on the top of the upper cover plate of the chamber and the bottom of the lower cover plate of the chamber, and the gas diffuses into the optical chamber of the sensor through the grid, which facilitates the gas exchange inside and outside the optical chamber of the sensor. The gas diffusion grid is a dustproof, waterproof, breathable and light-proof net, which prevents water and dust from entering the optical chamber of the sensor and adhering to the reflective surface of its inner wall, affecting the reflection effect of light, reducing the accuracy of the sensor, and preventing the light from the optical chamber from being emitted.

[0017] Beneficial effects of the utility model:

[0018] 1. The light source working circuit board and the detector working circuit board of the gas sensor described in the utility model are arranged in the hexagonal column reflection center, and the light source and the detector are respectively connected to the light source working circuit board and the detector working circuit board, which provides convenience for the assembly of the sensor.

[0019] 2. The various arc walls of the utility model and the various reflective walls of the reflective center are combined to form a reflective light path, providing a long optical path, and the optical path can be further extended by increasing the number of combinations of the arc walls and the reflective center walls according to actual needs.

[0020] 3. The gas interaction structure of the utility model is a gas diffusion grid, and the overall sensor has the advantages of simple structure, compact appearance, easy assembly and long optical path.

[0021] 4. The utility model adopts a chamber to provide a large optical path detection solution for the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a top view of a gas sensor with an arc-shaped wall chamber and a long optical path in the utility model.

[0023] Figure 2 This is a schematic cross-sectional view of a gas sensor with an arc-shaped wall chamber and a long optical path in the utility model. Figure I .

[0024] Figure 3 This is a cross-sectional diagram of a gas sensor with an arc-shaped wall chamber and a long optical path in the utility model. Figure II .

[0025] Figure 4 The utility model is a schematic diagram of the appearance of a gas sensor with an arc-shaped wall chamber and a long optical path.

[0026] Figure 5 It is a perspective schematic diagram of a gas sensor with an arc-shaped wall chamber and a long optical path in the utility model.

[0027] Figure 6 The utility model is a schematic diagram of the optical path of a gas sensor with an arc-shaped wall chamber and a long optical path.

[0028] Figure 7 It is a dimension marking diagram of a light source working circuit board in the utility model.

[0029] Figure 8 It is a dimension marking diagram of the detector working circuit board in the utility model.

[0030] Fig. 9 It is a dimensioning diagram of the reflection center in the present utility model.

[0031] Fig.10 It is a dimensioning diagram of the light-blocking plate in the present utility model.

[0032] Fig.11 It is a dimensioning diagram of the arc wall in the utility model.

[0033] Fig.12 It is a dimensioning diagram of the upper and lower chamber cover plates in the utility model.

[0034] Fig.13 It is a simulated illumination diagram of structured light by LightTools of a gas sensor with a curved wall chamber and a long optical path in the utility model.

[0035] In the figure: 1. optical chamber, 2. light source working circuit board, 3. detector working circuit board, 4. light source, 5. detector, 6. reflection center, 7. light baffle, 8. chamber upper cover, 9. chamber lower cover, 10. arc wall one, 11. arc wall two, 12. arc wall three, 13. arc wall four, 14. arc wall five, 15. reflection center wall one, 16. reflection center wall two, 17. reflection center wall three, 18. reflection center wall four, 19. reflection center wall five, 20. reflection center wall six, 21. light source mounting hole, 22. detector mounting hole, 23. gas diffusion grid one, 24. gas diffusion grid two, 25. gas diffusion grid three, 26. gas diffusion grid four, 27. gas diffusion grid five, 28. gas diffusion grid six, 29. gas diffusion grid seven, 30. gas diffusion grid eight. DETAILED DESCRIPTION

[0036] The utility model provides a gas sensor with an arc-shaped wall chamber and a long optical path, comprising a device housing, an optical chamber, a light source working circuit board and a detector working circuit board, and a light source and a detector respectively connected to the working circuit board, characterized in that: the sensor includes an optical chamber, the chamber as a whole is composed of an arc wall, a reflection hub and a cover plate, the sensor perimeter is composed of a columnar wall, in the optical chamber, the reflection hub is a hexagonal column, and its six walls and five arc walls are combined at a certain angle to form a multi-reflection optical path, and there is a light blocking plate on one side of the reflection hub and the arc wall to prevent the light emitted by the light source from directly entering the detector, and the above structure forms an overall chamber structure under the cover of the chamber upper cover plate and the chamber lower cover plate. Among them, the light source working circuit board and the detector working circuit board are arranged in the reflection hub, and the reflection hub is provided with a light source mounting hole and a detector mounting hole for installing the light source and the detector. A gas diffusion grid is arranged at the chamber upper cover plate and the chamber lower cover plate, and the gas diffuses into the optical chamber of the sensor through the grid, which is convenient for gas exchange inside and outside the optical chamber of the sensor. The light source and the detector are separated by a light blocking plate at the farthest end of the chamber optical path. The inner walls of all chambers are coated with a high reflectivity film for the light source. In the optical path system of the utility model, after the light beam is emitted from the light source, it is reflected on the arc wall to the reflection center wall, and then reflected on the next arc wall, and so on until it enters the detector. In this process, there are multiple reflections inside the chamber, and a very large absorption optical path is achieved in the space, which is suitable for gas sensors with compact structure, large measuring range and high measurement accuracy.

[0037] The utility model will be further described below in conjunction with the accompanying drawings.

[0038] like Figure 1-Figure 5 As shown, a gas sensor device with an arc-shaped wall chamber and a long optical path, in this embodiment, the technical solution of the arc-shaped wall reflective chamber specifically includes a device housing, an optical chamber 1, a light source working circuit board 2, a detector working circuit board 3, and a light source 4 and a detector 5 respectively connected to the working circuit boards;

[0039] The sensor includes an optical chamber 1, which is composed of an arc wall, a reflection center 6 and a cover plate: the circumference of the sensor is composed of a cylindrical wall. In the optical chamber 1, the reflection center 6 is a hexagonal column, and its six walls and five arc walls are combined at a certain angle to complete a multi-reflection light path. There is a light baffle 7 on one side of the reflection center 6 and the arc wall, so that the light emitted by the light source 4 enters the detector 5 with the maximum optical path. The above structure forms an overall chamber structure under the cover of the chamber upper cover 8 and the chamber lower cover 9.

[0040] A light source working circuit board 2 and a detection working circuit board 3 are arranged in the reflection center 6 for connecting the light source 4 and the detector 5 .

[0041] The arcuate walls include arcuate wall 10, arcuate wall 2 11, arcuate wall 3 12, arcuate wall 4 13 and arcuate wall 5 14. The above arcuate walls are combined with reflection hub wall 1 15, reflection hub wall 2 16, reflection hub wall 3 17, reflection hub wall 4 18, reflection hub wall 5 19 and reflection hub wall 6 20 of the reflection hub 6 at a certain angle to form a reflection light path.

[0042] All inner walls of the optical chamber 1 are coated with a high reflectivity film for the light source 4 .

[0043] The reflective central wall 15 is provided with a light source mounting hole 21, and the reflective central wall 6 20 is provided with a detector mounting hole 22 for mounting the light source 4 and the detector 5.

[0044] In the above structure, the top of the chamber upper cover plate 8 and the bottom of the chamber lower cover plate 9 are respectively provided with a gas diffusion grid 1 23, a gas diffusion grid 24, a gas diffusion grid 3 25, a gas diffusion grid 4 26, a gas diffusion grid 5 27, a gas diffusion grid 6 28, a gas diffusion grid 7 29, and a gas diffusion grid 8 30. The gas diffuses into the optical chamber 1 of the sensor through the grids, which facilitates the gas exchange inside and outside the optical chamber 1 of the sensor. The gas diffusion grid is a dustproof, waterproof, breathable and light-proof net, which prevents water and dust from entering the optical chamber of the sensor and adhering to its inner wall reflective surface, affecting the reflection effect of light, reducing the accuracy of the sensor, and preventing the light from the optical chamber from being emitted.

[0045] The light source 4 and the detector 5 are on two adjacent walls of the reflection center 6, and are separated from each other by a light blocking plate 7 to prevent light from entering the detector 5 with a small optical path and causing inaccurate detection.

[0046] The optical path system, such as Figure 6 As shown, after the light beam is emitted from the light source 4, it starts from the reflection central wall 15 in the optical chamber 1, and is emitted to the curved wall 10. Then the light is reflected to the reflection central wall 2 16, and then the light is reflected to the curved wall 2 11, reflected to the reflection central wall 3 17, reflected to the curved wall 3 12, reflected to the reflection central wall 4 18, reflected to the curved wall 4 13, reflected to the reflection central wall 5 19, reflected to the curved wall 5 14, and finally the light will be emitted into the detector 5 to complete the detection.

[0047] like Figure 7-Figure 12As shown, the structural dimensions of the present embodiment are as follows: the light source working circuit board 2 is L1=8mm, H1=12mm, T1=1mm, the light source 4 is composed of a column with a diameter of D1=3.18mm and a height of 4.81mm and a hemisphere with a diameter of D1=3.18mm; the detector working circuit board 3 is L2=10mm, H2=12mm, T2=1mm, the detector 5 is a column with a diameter of D2=9mm and a height of 1mm; the size of the reflection center 6 is a hexagonal column with a side length of L3=11.96mm and a height of H3=16mm, wherein the light source mounting hole 21 is arranged on the reflection center wall 15, with a diameter of D3=3.5mm, and the detector mounting hole 22 is arranged in the reflection center On the pivot wall six 20, the diameter is D4=9.4mm; the dimensions of the light shielding plate 7 are L4=13.45mm, H4=16mm, and T3=2mm; the dimensions of the arc wall column are height H5=16mm and diameter D5=70mm, wherein the arc wall one 10 to the arc wall five 14 are arcs with a radius of R1=21.04mm and are evenly spaced inside the column; the chamber upper cover plate 8 and the chamber lower cover plate 9 are columnar cover plates with a height of H6=2mm and a diameter of D6=70mm, wherein the gas diffusion grid one 23 to the gas diffusion grid eight 30 distributed thereon are four arc grids with a slit width of W1=1.5mm and a slit spacing of W2=1.5mm arrayed at equal angles on the two cover plates.

[0048] Specifically, Fig.13 As shown, the arc-shaped wall chamber long optical path gas sensor structure model of the utility model embodiment is simulated by light simulation of the optical simulation software Lighttools, the detector 5 receiving surface is set as a virtual surface, and the focusing evaluation function is added to optimize it to obtain its illumination distribution diagram. It can be seen that the illumination value of the detector 5 receiving surface is relatively high and the illumination distribution is uniform, which meets the design requirements.

[0049] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the utility model. They are not intended to limit the protection scope of the utility model. All equivalent methods or changes that do not deviate from the technology of the utility model should be included in the protection scope of the utility model.

Claims

1. A gas sensor with an arc-shaped wall chamber and a long optical path, characterized in that: The invention comprises an arc-shaped wall, a reflection center, a working circuit board and a cover plate; the arc-shaped wall and the cover plate can be assembled into a closed integral structure; the reflection center is vertically located at the inner center of the integral structure, the height of the reflection center is consistent with the height of the arc-shaped wall, and the upper and lower ends thereof are respectively flush with the upper and lower cover plates; the arc-shaped wall, the reflection center and the cover plate constitute a closed optical chamber (1) of the sensor; a light source (4) and a detector (5) are mounted on the working circuit board, the light source (4) and the detector (5) are separated by a light shielding plate (7) in the chamber, and the light emitted by the light source (4) reaches the detector (5) after multiple reflections in the optical chamber (1).

2. The arc-shaped wall chamber long light path gas sensor according to claim 1, characterized in that: The reflection center is a hollow hexagonal column structure, and its six faces are respectively reflection center wall one (15), reflection center wall two (16), reflection center wall three (17), reflection center wall four (18), reflection center wall five (19), and reflection center wall six (20); the inner surface of the arc wall is five arc surfaces, namely arc wall one (10), arc wall two (11), arc wall three (12), arc wall four (13), and arc wall five (14), and the endpoints of the five arc surfaces are connected to each other; the five corners of the hexagonal column point to the center points of the five arcs respectively, so that a reflection light path in the chamber is formed in this combination.

3. The arc-shaped wall chamber long light path gas sensor according to claim 2, characterized in that: A light blocking plate is arranged at the sixth corner of the hexagonal column structure, and the upper and lower ends of the light blocking plate are flush with the upper and lower cover plates respectively. The light source working circuit board and the detector working circuit board are respectively installed inside the hexagonal columns on both sides of the light blocking plate. Light source mounting holes and detector mounting holes are opened on the sides of the hexagonal columns on both sides of the light blocking plate. The light source is fixed to the light source working circuit board through the light source mounting hole, and the detector is fixed to the detector working circuit board through the detector mounting hole. The light blocking plate separates the light source and the detector.

4. The arc-shaped wall chamber long light path gas sensor according to claim 3, characterized in that: The light emitted by the light source is reflected multiple times through the reflective light path composed of the reflective center and the arc wall. That is, the light source is reflected on the arc wall to the wall of the reflective center, and then reflected to the next arc wall, and so on, until it enters the detector, realizing a long optical path.

5. A gas sensor with an arc-shaped wall chamber and a long optical path according to claim 2 or 3, characterized in that: The combined quantity of the arc-shaped wall and the reflective central wall is adjustable.

6. The arc-shaped wall chamber long light path gas sensor according to claim 2, characterized in that: The outer surface of the arc-shaped wall is a cylindrical structure.

7. The arc-shaped wall chamber long light path gas sensor according to claim 1, characterized in that: The inner walls of the chamber are coated with a film with high reflectivity to the light source.

8. The arc-shaped wall chamber long light path gas sensor according to claim 3, characterized in that: The cover plate comprises an upper cover plate and a lower cover plate. A plurality of gas diffusion grids are arranged on the top of the upper cover plate and the bottom of the chamber lower cover plate. The gas diffuses into the optical chamber of the sensor through the grids.

9. The arc-shaped wall chamber long light path gas sensor according to claim 8, characterized in that: The gas diffusion grid is a dustproof, waterproof, breathable and light-proof grid.

10. The arc-shaped wall chamber long light path gas sensor according to claim 8, characterized in that: The dimensions of the sensor are as follows: The light source working circuit board (2) has L1=8mm, H1=12mm, T1=1mm, and the light source (4) is composed of a column with a diameter of D1=3.18mm and a height of 4.81mm and a hemisphere with a diameter of D1=3.18mm; the detector working circuit board (3) has L2=10mm, H2=12mm, T2=1mm, and the detector (5) is a column with a diameter of D2=9mm and a height of 1mm; the size of the reflection center (6) is a hexagonal column with a side length of L3=11.96mm and a height of H3=16mm, wherein the light source mounting hole (21) is arranged on the reflection center wall 1 (15) and has a diameter of D3=3.5mm, and the detector mounting hole (22) is arranged on the reflection center wall 6 (20) and has a diameter of D4=9.4mm; the size of the light blocking plate (7) is L4=13.4 5mm, H4=16mm, T3=2mm; the dimensions of the arc wall are height H5=16mm, diameter D5=70mm, arc wall 1 (10) to arc wall 5 (14) are arcs with a radius R1=21.04mm and are evenly spaced inside the column; the chamber upper cover plate (8) and the chamber lower cover plate (9) are columnar cover plates with a height of H6=2mm and a diameter of D6=70mm, gas diffusion grid 1 (23) to gas diffusion grid 4 (26) are distributed on the chamber upper cover plate (8), and gas diffusion grid 5 (27) to gas diffusion grid 8 (30) are distributed on the chamber lower cover plate (9), and gas diffusion grid 1 (23) to gas diffusion grid 8 (30) are four arc grids with a slit width of W1=1.5mm and a slit spacing of W2=1.5mm are arrayed at equal angles on the two cover plates.

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