Compact infrared optical gas absorption cell and infrared gas sensor thereof
By designing a compact infrared optical gas absorption cell, using the positioning coordination of the upper and lower covers of the cavity and the combined installation of the sealant, combined with the design that the center of the infrared light source and the detector are located on the same circumference, the problems of large volume and short optical path in the existing infrared gas sensor are solved, and the effect of achieving a long light path in a small space is achieved.
Patent Information
- Application Number
- CN202422032197.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-08-21
AI Technical Summary
In existing infrared gas sensors, the design of infrared light sources and detectors leads to large volumes of optical cavity, which makes it difficult to achieve miniaturization. At the same time, in order to increase sensitivity and resolution, a longer optical path is required, but this conflicts with the requirement of small size.
A compact infrared optical gas absorption tank was designed, and the compact structure of the optical cavity was realized through the positioning coordination between the upper and lower covers of the cavity and the sealant combination installation. The design where the infrared light source and the detector center are located on the same circumference, a long light path in which light is reflected multiple times in the cavity is realized.
It realizes the effective increase of the optical path while ensuring a small space and a long light path, and has the advantages of simple structure, convenient assembly, small appearance and long light path.
Smart Images
Figure CN223021929U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a gas absorption cell, in particular to the field of infrared gas sensors, and specifically refers to a compact infrared optical gas absorption cell and an infrared gas sensor thereof. Background Art
[0002] An infrared gas sensor detects target gases present in the air by using the principle of non-dispersive infrared (NDIR), and has the advantages of long service life, high accuracy, anti-poisoning, etc., and is widely used in the field of gas detection. An infrared gas sensor usually consists of four parts: an infrared light source, an optical cavity, a detector, and a signal acquisition and processing circuit. Among them, the combination of the infrared light source, the optical cavity and the detector can also be called an infrared optical gas absorption cell. Usually, an infrared gas sensor adopts an optical structure in which an infrared light source emits infrared spectra at one end of the optical cavity, and a detector receives the infrared spectra at the other end of the optical cavity. After the infrared spectra are emitted, they are absorbed by the target gas in the optical cavity and converge on the detector after being reflected multiple times by the inner wall of the optical cavity. The information of the target gas can be obtained by analyzing the spectral signals received by the detector.
[0003] In existing infrared gas sensors, the infrared light source and the detector are mostly cylindrical. The infrared light source and the detector need to be combined with the optical cavity to form a complete optical path, and the pins of the infrared light source and the detector need to be soldered to the circuit board. This situation causes the design of the optical cavity to be limited by the soldering methods of the infrared light source, the detector and the circuit board. In order to reduce the overall size of the sensor, it is necessary to reduce the volume of the optical cavity. In order to increase the sensitivity and resolution of the infrared gas sensor, a longer optical path is required. Therefore, the infrared optical gas absorption cell is the core component of the infrared gas sensor, which directly determines the performance and external dimensions of the infrared gas sensor. Therefore, a reasonable design of the infrared optical gas absorption cell is beneficial to the miniaturization development of the infrared gas sensor. Summary of the Utility Model
[0004] The purpose of the utility model is to overcome the above-mentioned disadvantages in the prior art, and provide a compact infrared optical gas absorption cell and a corresponding infrared gas sensor.
[0005] In order to achieve the above purpose, a compact infrared optical gas absorption cell of the utility model is as follows:
[0006] The compact infrared optical gas absorption cell is mainly characterized in that the absorption cell includes: an upper cavity cover, a lower cavity cover, an infrared light source and a detector. Among them, the upper cavity cover is provided with a positioning boss, and the lower cavity cover is provided with a positioning groove. The upper cavity cover and the lower cavity cover are respectively positioned and fitted through the positioning boss and the positioning groove, and the upper cavity cover and the lower cavity cover are combined and installed to form an optical cavity by means of sealing glue; and
[0007] The centers of the infrared light source and the detector are located on the same circumference, so that the infrared light emitted by the infrared light source is reflected multiple times in the optical cavity and then converges into the detector.
[0008] Preferably, an optical incident hole, a first optical exit hole and a second optical exit hole are arranged in the cavity of the lower cavity cover, and the detector is arranged directly below the first optical exit hole and the second optical exit hole; and the infrared light source is arranged directly below the optical incident hole.
[0009] Preferably, a first reflecting surface and a second reflecting surface are further arranged along the inner side of the positioning boss on the upper cavity cover, and the first reflecting surface and the second reflecting surface respectively correspond to the first optical exit hole and the second optical exit hole.
[0010] Preferably, the first optical exit hole and the second optical exit hole of the circumference where the center of the detector is located form a 45° angle with the first reflecting surface and the second reflecting surface.
[0011] Preferably, the centers of the infrared light source and the detector are located on the same circumference. The infrared light emitted by the infrared light source is reflected multiple times to the left and right in the optical cavity, then converges on the first reflecting surface and the second reflecting surface, and finally converges on the detector after being reflected by the first reflecting surface and the second reflecting surface.
[0012] Preferably, an annular gas diffusion hole is further arranged on the upper cavity cover.
[0013] An infrared gas sensor is mainly characterized in that it includes the above-mentioned compact infrared optical gas absorption cell.
[0014] Preferably, it further includes a signal acquisition board, a housing, a waterproof and breathable membrane, and pins. Among them, the infrared light source and the detector are both arranged on the signal acquisition board, the pins are arranged at the bottom of the signal acquisition, the housing is a hollow structure, and after the cavity upper cover, the cavity lower cover, the infrared light source, the detector, and the signal acquisition board are assembled in sequence, they are accommodated in the housing; an air inlet hole is arranged in a circular shape around the top of the housing, and the waterproof and breathable membrane is arranged on the upper surface of the housing.
[0015] Preferably, the signal acquisition board is set to be smaller than the inner cavity diameter of the housing, and the pins are exposed to the surrounding environment.
[0016] By adopting the compact infrared optical gas absorption cell and its infrared gas sensor of the present invention, it is possible to effectively increase the optical path while ensuring a small space and a long optical path, and it has the advantages of simple structure, convenient assembly, small size, and long optical path. Description of the Drawings
[0017] Figure 1 It is an exploded view of the compact infrared optical gas absorption cell of the present invention.
[0018] Figure 2 It is a schematic structural diagram of the cavity upper cover of the present invention.
[0019] Figure 3 It is a schematic structural diagram of the cavity lower cover of the present invention.
[0020] Figure 4 It is an exploded view of the infrared gas sensor of the present invention.
[0021] Reference Signs
[0022] 1 Cavity Upper Cover
[0023] 2 Cavity Lower Cover
[0024] 3 Infrared Light Source
[0025] 4 Detector
[0026] 5 Signal Acquisition Board
[0027] 6 Housing
[0028] 7 Waterproof and Breathable Membrane
[0029] 8 Pins
[0030] 9 Annular Gas Diffusion Hole
[0031] 10 First Reflecting Surface
[0032] 11 Second Reflecting Surface
[0033] 12 Positioning boss
[0034] 13 Optical incident hole
[0035] 14 First optical exit hole
[0036] 15 Second optical exit hole Detailed implementation manners
[0037] In order to more clearly describe the technical content of the present utility model, the following will be further described in conjunction with specific embodiments.
[0038] Before detailing the embodiments according to the present utility model, it should be noted that, hereinafter, the terms "comprising", "including" or any other variant are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.
[0039] Please refer to Figures 1 to 3 As shown, for the compact infrared optical gas absorption cell of the present utility model, the absorption cell includes: a cavity upper cover 1, a cavity lower cover 2, an infrared light source 3 and a detector 4. Among them, the cavity upper cover 1 is provided with a positioning boss 12, and the cavity lower cover 2 is provided with a positioning groove 16. The cavity upper cover 1 and the cavity lower cover 2 are respectively positioned and fitted through the positioning boss 12 and the positioning groove 16, and the cavity upper cover 1 and the cavity lower cover 2 are combined and installed to form an optical cavity by means of sealing glue; and
[0040] The centers of the infrared light source 3 and the detector 4 are located on the same circumference, so that the infrared light emitted by the infrared light source 3 is reflected multiple times in the optical cavity and then converges into the detector 4.
[0041] As a preferred embodiment of the present utility model, an optical incident hole 13, a first optical exit hole 14 and a second optical exit hole 15 are provided in the cavity of the cavity lower cover 2. The detector 4 is arranged directly below the first optical exit hole 14 and the second optical exit hole 15; and the infrared light source 3 is arranged directly below the optical incident hole 13.
[0042] As a preferred embodiment of the present utility model, a first reflecting surface 10 and a second reflecting surface 11 are further provided along the inner side of the positioning boss 12 on the cavity upper cover 1. The first reflecting surface 10 and the second reflecting surface 11 respectively correspond to the first optical exit hole 14 and the second optical exit hole 15.
[0043] As a preferred embodiment of the present utility model, the first optical exit hole 14 and the second optical exit hole 15 at the center of the circumference where the detector 4 is located form a 45° angle with the first reflecting surface 10 and the second reflecting surface 11.
[0044] As a preferred embodiment of the present utility model, the centers of the infrared light source 3 and the detector 4 are located on the same circumference. After the infrared light emitted by the infrared light source 3 is reflected multiple times in the left and right directions respectively in the optical cavity, it converges on the first reflecting surface 10 and the second reflecting surface 11, and after being reflected by the first reflecting surface 10 and the second reflecting surface 11, it finally converges on the detector 4.
[0045] As a preferred embodiment of the present utility model, an annular gas diffusion hole 9 is further provided on the upper cover 1 of the cavity.
[0046] Please refer to Figure 4 As shown, this infrared gas sensor, wherein, the sensor includes the compact infrared optical gas absorption cell described above.
[0047] As a preferred embodiment of the present utility model, the sensor further includes a signal acquisition board 5, a housing 6, a waterproof and breathable membrane 7 and pins 8. Among them, the infrared light source 3 and the detector 4 are both arranged on the signal acquisition board 5, the pins 8 are arranged at the bottom of the signal acquisition board 5, the housing 6 is a hollow structure, and after the upper cover 1 of the cavity, the lower cover 2 of the cavity, the infrared light source 3, the detector 4 and the signal acquisition board 5 are assembled in sequence, they are accommodated in the housing 6; an air inlet hole is provided in a circular shape around the top of the housing 6, and the waterproof and breathable membrane 7 is arranged on the upper surface of the housing 6.
[0048] As a preferred embodiment of the present utility model, the signal acquisition board 5 is set to be smaller than the inner diameter of the housing 6, and the pins 8 are exposed to the surrounding environment.
[0049] In actual application, the upper cover 1 of the cavity and the lower cover 2 of the cavity are installed together to form an optical cavity, and the overall appearance of this optical cavity is cylindrical. In this embodiment, a positioning boss 12 is provided on the upper cover 1 of the cavity, and a corresponding positioning groove 16 is provided on the lower cover 2 of the cavity. Through the cooperation and positioning of the positioning boss 12 on the upper cover 1 of the cavity and the positioning groove 16 on the lower cover 2 of the cavity, the upper cover 1 of the cavity and the lower cover 2 of the cavity are installed together by means of glue sealing connection. The main functions of the positioning boss 12 and the positioning groove 16 are to ensure accurate positioning when the upper cover 1 of the cavity and the lower cover 2 of the cavity are installed together.
[0050] The overall appearance of the lower cavity cover 2 is cylindrical, and an optical incident hole 13, a first optical exit hole 14, and a second optical exit hole 15 are provided in the cavity. The infrared light source 3 is installed at the optical incident hole 13, and the detector 4 is installed below the first optical exit hole 14 and the second optical exit hole 15. The second optical incident hole 15 and the first optical incident hole 14 of the circumference where the center of the detector is located form a 45° angle with the first reflecting surface 10 and the second reflecting surface 11 on the upper cavity cover 1. The centers of the infrared light source 3 and the detector 4 are located on the same circumference, which is beneficial for the infrared light to be reflected multiple times to the left and right directions respectively in the upper cavity cover 1 and the lower cavity cover 2, and then converge onto the corresponding first reflecting surface 10 and second reflecting surface 11 on the upper cavity cover 1 respectively. After being reflected by the first reflecting surface 10 and the second reflecting surface 11, the light beam finally converges onto the detector 4 for reception.
[0051] Effectively extend the optical reflection path, so as to achieve that while ensuring the extension of the optical reflection path, the compact infrared optical gas absorption cell is as small as possible.
[0052] The infrared gas sensor further includes a housing 6, a waterproof and breathable membrane 7, and pins 8. Among them, the housing 6 houses the upper cavity cover 1, the lower cavity cover 2, the infrared light source 3, the detector 4, and the signal acquisition board 5. The waterproof and breathable membrane 7 is arranged on the upper surface of the air inlet hole of the housing 6. The pins 8 are arranged on the signal acquisition board 5. The housing 6 is a hollow cylindrical structure with an air inlet hole at the top. The upper cavity cover 1, the lower cavity cover 2, and the signal acquisition board 5 are housed in the housing 6 from top to bottom, so that the compact infrared optical gas absorption cell is exactly installed in the housing 6. The signal acquisition board 5 is smaller than the inner cavity diameter of the housing 6, and the pins 8 are exposed to the surrounding environment. The waterproof and breathable membrane 7 is arranged on the air inlet hole of the housing 6, mainly to prevent water and dust from entering the compact infrared optical gas absorption cell and adhering to its inner wall, affecting the light reflection effect. The waterproof and breathable membrane 7 and the housing 6 cooperate to install the upper cavity cover 1 in the housing 6, avoiding the upper cavity cover 1 being exposed in the surrounding environment. Therefore, the above infrared gas sensor provided in this embodiment has the advantages of simple structure, convenient assembly, small size, and long optical path while ensuring a long optical path.
[0053] By adopting the compact infrared optical gas absorption cell and its infrared gas sensor of the present utility model, it is possible to effectively increase the optical path while ensuring a small space and a long optical path, and has the advantages of simple structure, convenient assembly, small size, and long optical path.
[0054] In this specification, the present utility model has been described with reference to its specific embodiments. However, it is obvious that various modifications and variations can still be made without departing from the spirit and scope of the present utility model. Therefore, the specification and the drawings should be regarded as illustrative rather than restrictive.
Claims
1. A compact infrared optical gas absorption cell, characterized in that: The absorption cell comprises: a cavity upper cover (1), a cavity lower cover (2), an infrared light source (3) and a detector (4), wherein the cavity upper cover (1) is provided with a positioning boss (12), and the cavity lower cover (2) is provided with a positioning groove (16), the cavity upper cover (1) and the cavity lower cover (2) are positioned and matched by the positioning boss (12) and the positioning groove (16) respectively, and the cavity upper cover (1) and the cavity lower cover (2) are assembled and installed to form an optical cavity by means of sealing; and The centers of the infrared light source (3) and the detector (4) are located on the same circumference, so that the infrared light emitted by the infrared light source (3) converges into the detector (4) after multiple reflections in the optical cavity.
2. The compact infrared optical gas absorption cell according to claim 1, characterized in that: An optical entrance hole (13), a first optical exit hole (14) and a second optical exit hole (15) are arranged in the cavity of the cavity lower cover (2); the detector (4) is arranged directly below the first optical exit hole (14) and the second optical exit hole (15); and the infrared light source (3) is arranged directly below the optical entrance hole (13).
3. The compact infrared optical gas absorption cell according to claim 2, characterized in that: The cavity upper cover (1) is also provided with a first reflection surface (10) and a second reflection surface (11) along the inner side of the positioning boss (12); the first reflection surface (10) and the second reflection surface (11) respectively correspond to the first optical exit hole (14) and the second optical exit hole (15).
4. The compact infrared optical gas absorption cell according to claim 3, characterized in that: The first optical exit hole (14) and the second optical exit hole (15) which are included in the circumference of the center of the detector (4) form an angle of 45° with the first reflection surface (10) and the second reflection surface (11).
5. The compact infrared optical gas absorption cell according to claim 4, characterized in that: The centers of the infrared light source (3) and the detector (4) are located on the same circumference. The infrared light emitted by the infrared light source (3) is reflected multiple times in the left and right directions in the optical cavity, and then converges on the first reflection surface (10) and the second reflection surface (11). After being reflected by the first reflection surface (10) and the second reflection surface (11), it finally converges on the detector (4).
6. The compact infrared optical gas absorption cell according to claim 1, characterized in that: The cavity upper cover (1) is also provided with an annular gas diffusion hole (9).
7. An infrared gas sensor, characterized in that: The invention comprises the compact infrared optical gas absorption cell according to any one of claims 1 to 6.
8. The infrared gas sensor according to claim 7, characterized in that: It also includes a signal acquisition board (5), a shell (6), a waterproof breathable membrane (7) and a pin (8), wherein the infrared light source (3) and the detector (4) are both arranged on the signal acquisition board (5), the pin (8) is arranged at the bottom of the signal acquisition board (5), the shell (6) is a hollow structure, and the cavity upper cover (1), the cavity lower cover (2), the infrared light source (3), the detector (4) and the signal acquisition board (5) are sequentially assembled and accommodated in the shell (6); the top of the shell (6) is provided with air inlet holes in a circular shape, and the waterproof breathable membrane (7) is arranged on the upper surface of the shell (6).
9. The infrared gas sensor according to claim 8, characterized in that: The signal acquisition board (5) is configured to be smaller than the inner cavity diameter of the housing (6), and the pins (8) are exposed to the surrounding environment.