阅读说明：本技术 一种基于ndir技术的红外气体传感器 (Infrared gas sensor based on NDIR technology ) 是由 肖龙伟 张文勇 陈永刚 牟晓晖 于 2020-09-09 设计创作，主要内容包括：本发明涉及传感器技术领域,公开了一种基于NDIR技术的红外气体传感器,包括用于产生红外光的光源模块、用于接收红外光的检测模块、以及用于将光源模块所发出的红外光传导至检测模块上的环形光路传导组件；环形光路传导组件包括外壳,外壳内部形成有用于容纳待检测气体的气体腔室,光源模块与检测模块均设置在气体腔室内部,光源模块发出的红外光在气体腔室内经过多次反射后,照射在检测模块上,检测模块根据所接收到的红外光的强度检测出气体腔室内目标气体的气体浓度。本申请提供的一种基于NDIR技术的红外气体传感器,光线在气体腔室内经过多次反射,使得传感器的光程更长,检测结果更加精准,同时传感器的体积也更小。(The invention relates to the technical field of sensors, and discloses an infrared gas sensor based on an NDIR (non-dispersive infrared) technology, which comprises a light source module for generating infrared light, a detection module for receiving the infrared light, and an annular light path conduction assembly for conducting the infrared light emitted by the light source module to the detection module; annular light path conduction subassembly includes the shell, and the shell is inside to be formed with to be used for holding the gaseous gas chamber that waits to detect, and light source module and detection module all set up inside gas chamber, and the infrared light that light source module sent is after the multiple reflection in gas chamber, shine on detection module, and detection module detects out the gaseous concentration of the interior target gas of gas chamber according to the intensity of the infrared light received. The application provides a pair of infrared gas sensor based on NDIR technique, light passes through multiple reflection in the gas cavity for the optical path of sensor is longer, and the testing result is more accurate, and the volume of sensor is also littleer simultaneously.)

1. An infrared gas sensor based on NDIR technology is characterized by comprising a light source module for generating infrared light, a detection module for receiving the infrared light, and an annular light path conduction assembly for conducting the infrared light emitted by the light source module to the detection module; the annular light path conduction assembly comprises a shell, a gas cavity for containing gas to be detected is formed in the shell, the light source module and the detection module are both arranged in the gas cavity, infrared light emitted by the light source module irradiates the detection module after being reflected for multiple times in the gas cavity, and the detection module detects the gas concentration of target gas in the gas cavity according to the intensity of the received infrared light.

2. The infrared gas sensor based on NDIR technology of claim 1, wherein said annular light path conducting component comprises a first reflecting member disposed inside said gas chamber, said first reflecting member having a first reflecting end surface, said first reflecting end surface forming an angle of 45 degrees with the light path of the infrared light emitted by said light source module.

3. The infrared gas sensor based on NDIR technique as claimed in claim 1, wherein the housing has a first reflective wall facing the inside of the gas chamber, and the gas chamber has therein an annular plate having a second reflective wall facing the first reflective wall, and the infrared light emitted from the light source module can be reflected on the first reflective wall and the second reflective wall multiple times.

4. The infrared gas sensor based on NDIR technology as claimed in claim 3, wherein said first reflecting wall is in the shape of a circular ring, said second reflecting wall is in the shape of a circular ring, and said first reflecting wall and said second reflecting wall are arranged in concentric circles.

5. The infrared gas sensor based on NDIR technology of claim 3, wherein the annular light path conducting component comprises a second reflecting member and a third reflecting member, the second reflecting member has a reflecting arc surface, the third reflecting member has a second reflecting end surface, the infrared light emitted from the light source module irradiates on the reflecting arc surface, reflects on the second reflecting end surface, and irradiates on the detection module after being reflected by the second reflecting end surface.

6. The infrared gas sensor based on NDIR technology as claimed in claim 5, wherein one end of the second reflector is fixedly connected to the annular plate, the annular plate has a first opening facing the reflective curved surface, the third reflector is disposed on the annular plate and located in the first opening, a detection cavity is formed among the annular plate, the second reflector and the third reflector, the detection cavity is located in the gas chamber and communicates with the gas chamber, and the detection module is disposed in the detection cavity.

7. The infrared gas sensor based on NDIR technology as claimed in claim 5, wherein the second reflecting end face forms an angle of 45 degrees with the optical path of the infrared light emitted from the light source module.

8. The infrared gas sensor based on NDIR technology as claimed in any one of claims 1 to 7, wherein the detection module has at least one light path receiving site for receiving infrared light emitted from the light source module and passing through the gas chamber.

9. The infrared gas sensor based on NDIR technology according to any of claims 1 to 7, characterized in that the gas chamber is in communication with the outside and is in gas exchange with the outside through a waterproof gas permeable membrane.

10. The infrared gas sensor based on NDIR technology of any one of claims 1 to 7, further comprising a PCB board on which said detection module is disposed and a pin electrically connected to said PCB board, said pin being used to mount said sensor at a designated position.

Technical Field

The invention relates to the technical field of sensors, in particular to an infrared gas sensor based on an NDIR technology.

Background

An infrared gas sensor based on NDIR (non-dispersive infrared technology) technology uses a broad-spectrum blackbody radiation source as a light source of the infrared sensor, and light passes through a measured gas in a light path to reach an infrared detector. The working principle of the gas sensing device is that the absorption characteristics are selected based on the near infrared spectra of different gas molecules, and the gas components are identified and the concentration of the gas components is determined by utilizing the relation (Lambert-Beer law) between the gas concentration and the absorption intensity.

Wherein, the longer the optical path taken by the light in the sensor, the more accurate the detection result obtained by the sensor. The optical path of the existing NDIR gas sensor is mostly a linear optical path, and in order to make the detection result of the sensor more accurate, the optical path of the detection light needs to be set long enough, which causes the problem that the volume of the existing gas sensor is larger.

Disclosure of Invention

The invention aims to provide an infrared gas sensor based on an NDIR technology, and aims to solve the problems of large volume and short optical path of the gas sensor in the prior art.

In order to solve the technical problems, the invention adopts a technical scheme that: the infrared gas sensor based on the NDIR technology comprises a light source module for generating infrared light, a detection module for receiving the infrared light, and an annular light path conduction component for conducting the infrared light emitted by the light source module to the detection module; the annular light path conduction assembly comprises a shell, a gas cavity for containing gas to be detected is formed in the shell, the light source module and the detection module are both arranged in the gas cavity, infrared light emitted by the light source module irradiates the detection module after being reflected for multiple times in the gas cavity, and the detection module detects the gas concentration of target gas in the gas cavity according to the intensity of the received infrared light.

Further, annular light path conduction subassembly is including setting up the inside first reflection part of gas chamber, first reflection part has first reflection terminal surface, first reflection terminal surface with the light path of the infrared light that light source module sent is 45 degrees contained angles.

Further, the housing has a first reflecting wall facing the inside of the gas chamber, and the gas chamber has a ring-shaped plate therein, the ring-shaped plate having a second reflecting wall facing the first reflecting wall, and the infrared light emitted from the light source module can be reflected on the first reflecting wall and the second reflecting wall multiple times.

Furthermore, the first reflecting wall is annular, the second reflecting wall is annular, and the first reflecting wall and the second reflecting wall are arranged in a concentric circle.

Furthermore, the annular light path conducting component comprises a second reflecting piece and a third reflecting piece, the second reflecting piece is provided with a reflecting arc surface, the third reflecting piece is provided with a second reflecting end surface, the infrared light emitted by the light source module irradiates on the reflecting arc surface, reflects on the second reflecting end surface, and irradiates on the detection module after being reflected by the second reflecting end surface.

Furthermore, one end of the second reflector is fixedly connected with the annular plate, the annular plate is provided with a first opening facing the reflecting arc surface, the third reflector is arranged on the annular plate and located in the first opening, a detection cavity is formed among the annular plate, the second reflector and the third reflector, the detection cavity is located in the gas cavity and communicated with the gas cavity, and the detection module is arranged in the detection cavity.

Furthermore, the second reflecting end face and the light path of the infrared light emitted by the light source module form an included angle of 45 degrees.

Further, the detection module has at least one light path receiving position for receiving infrared light emitted from the light source module and passing through the gas chamber.

Further, the gas chamber is communicated with the outside and exchanges gas with the outside through the waterproof breathable film.

The detection module is arranged on the PCB, and the contact pin is used for installing the sensor at a specified position.

Compared with the prior art, the invention mainly has the following beneficial effects:

according to the infrared gas sensor based on the NDIR technology, infrared light emitted by the light source module irradiates the detection module after being reflected for multiple times in the gas cavity, wherein under the condition that the distance between the light source module and the detection module is the same, the path of the light which reaches the detection module after being reflected for multiple times is longer than the path of the light which is emitted from the light source module and directly irradiates the detection module, so that the light is reflected for multiple times in the gas cavity, the optical path of the sensor is longer, the detection result is more accurate, and the size of the sensor is smaller.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an infrared gas sensor based on NDIR technology according to an embodiment of the present invention;

FIG. 2 is an exploded view of an infrared gas sensor based on NDIR technology according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an internal structure of an infrared gas sensor based on NDIR technology according to an embodiment of the present invention;

fig. 4 is a top view of an internal structure of an infrared gas sensor based on NDIR technology according to an embodiment of the present invention.

Reference numerals: 1-light source module, 2-detection module, 3-annular light path conducting component, 4-waterproof breathable film, 5-contact pin, 21-light path receiving position, 31-shell, 32-first reflector, 33-annular plate, 34-second reflector, 35-third reflector, 311-gas chamber and 312-detection chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms may be understood by those skilled in the art according to specific circumstances.

The following describes the implementation of the present invention in detail with reference to specific embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an infrared gas sensor based on NDIR technology according to an embodiment of the present invention, and fig. 2-4 are also shown; the infrared gas sensor based on the NDIR technology provided by the embodiment includes a light source module 1 for generating infrared light, a detection module 2 for receiving the infrared light, and an annular light path conduction assembly 3 for conducting the infrared light emitted by the light source module 1 to the detection module 2; the annular light path conducting component 3 comprises a shell 31, a gas chamber 311 for accommodating a gas to be detected is formed in the shell 31, the light source module 1 and the detection module 2 are both arranged in the gas chamber 311, infrared light emitted by the light source module 1 is irradiated on the detection module 2 after being reflected for multiple times in the gas chamber 311, and the detection module 2 detects the gas concentration of a target gas in the gas chamber 311 according to the intensity of the received infrared light.

Above-mentioned infrared gas sensor based on NDIR technique that provides, the infrared light that light source module 1 sent shines on detection module 2 after the multiple reflection in gas chamber 311, wherein, under the same condition of distance between light source module 1 and detection module 2, the route that light reached detection module 2 after the multiple reflection was walked is longer than the route that light sent direct irradiation on detection module 2 from light source module 1, like this, light is through the multiple reflection in gas chamber 311, make the optical path of sensor longer, the testing result is more accurate, the volume of sensor is also littleer simultaneously.

The application provides a pair of infrared gas sensor based on NDIR technique through setting up annular light path conduction subassembly 3, can be with the infrared light conduction that light source module 1 sent to detection module 2 on, simultaneously, detection module 2 can detect out the gaseous concentration of target gas in the gas chamber 311 according to the intensity of received infrared light. Since the infrared light is absorbed by the gas molecules during the propagation of the infrared light in the gas chamber 311, and the absorption intensities of the light by different gas molecules are different, the gas concentration of the target gas in the gas chamber 311 can be obtained according to the Lambert-Beer law.

Referring to fig. 2-4, as an embodiment of the present invention, the annular light path conducting assembly 3 includes a first reflecting member 32 disposed inside the gas chamber 311, and the first reflecting member 32 has a first reflecting end surface, and preferably, the first reflecting end surface forms an angle of 45 degrees with the light path of the infrared light emitted from the light source module 1. The first reflecting member 32 forms an included angle of 45 degrees with the light path, so that the infrared light emitted by the light source module 1 can be converged on the first reflecting member 32 as much as possible, and the infrared light is reflected into the gas chamber 311 through the first reflecting end surface, and meanwhile, the light loss caused by light scattering when the infrared light is irradiated from the light source module 1 can also be reduced.

Preferably, the optical path of the infrared light emitted by the light source module 1 is perpendicular to the horizontal plane, and the optical path is reflected by the first reflecting member 32 and then emitted in parallel to the horizontal plane.

Specifically, the housing 31 has a first reflection wall facing the inside of the gas chamber 311, the inside of the gas chamber 311 has an annular plate 33, the annular plate 33 has a second reflection wall facing the first reflection wall, and the infrared light emitted from the light source module 1 can be reflected multiple times on the first reflection wall and on the second reflection wall. After being reflected by the first reflecting member 32, the infrared light emitted by the light source module 1 irradiates the first reflecting wall, is reflected by the first reflecting wall, irradiates the second reflecting wall, is reflected by the second reflecting wall, and irradiates the first reflecting wall, so that after multiple reflections, the infrared light irradiates the detection module 2. Thus, the path of the infrared light after multiple reflections in the gas chamber 311 is longer, the detection result of the sensor is more accurate, and the volume of the sensor is smaller.

The first reflecting wall is in a ring shape, the second reflecting wall is in a ring shape, and the first reflecting wall and the second reflecting wall are arranged in a concentric circle. The first reflecting wall and the second reflecting wall with arc surfaces can converge the infrared light beams reflected by the first reflecting piece 32 as much as possible, so that the light loss caused in the process of transmitting infrared light in the gas chamber 311 is reduced, the utilization rate of light in the sensor is improved, and energy is saved. Preferably, the light beam reflected by the first reflecting member 32 is parallel to the tangential direction of the second reflecting wall.

Specifically, the annular light path conducting assembly 3 includes a second reflecting member 34 and a third reflecting member 35, the second reflecting member 34 has a reflecting arc surface, the third reflecting member 35 has a second reflecting end surface, the infrared light emitted by the light source module 1 irradiates on the reflecting arc surface, reflects on the second reflecting end surface, and irradiates on the detection module 2 after being reflected by the second reflecting end surface. Thus, under the guidance of the second reflector 34 and the third reflector 35, the infrared light emitted by the light source module 1 can accurately irradiate on the detection module 2.

More specifically, one end of the second reflector 34 is fixedly connected with the annular plate 33, the annular plate 33 has a first opening facing the reflective arc surface, the third reflector 35 is arranged on the annular plate 33 and located in the first opening, a detection cavity 312 is formed among the annular plate 33, the second reflector 34 and the third reflector 35, the detection cavity 312 is located in the gas chamber 311 and is communicated with the gas chamber 311, and the detection module 2 is arranged in the detection cavity 312. The third reflector 35 is arranged in the first opening of the annular plate 33, and the receiving detection cavity 312 is arranged among the annular plate 33, the second reflector 34 and the third reflector 35, so that the internal structure of the sensor can be more compact, and the volume of the sensor can be reduced.

After being reflected for multiple times between the first reflecting wall and the second reflecting wall, the infrared light irradiates the reflecting arc surface of the second reflecting member 34, is reflected by the reflecting arc surface, irradiates the second reflecting end surface of the third reflecting member 35, and finally irradiates the detection module 2 after being reflected by the second reflecting end surface. Because the light easily takes place the scattering in the in-process that propagates in gas chamber 311 to cause the light loss, set the plane of reflection of second reflector 34 into the arc, can be favorable to the reflection cambered surface to assemble the infrared light that propagates in gas chamber 311 and reflect on the second reflection terminal surface, thereby reduce the light loss of infrared light, improve the utilization ratio of light in the sensor, the energy saving.

Preferably, the second reflecting end face forms an included angle of 45 degrees with the optical path of the infrared light irradiated on the second reflecting end face, so that the infrared light irradiated on the second reflecting end face can be reflected onto the detection module 2 as much as possible. Other angles are of course possible and the invention is not limited in this regard.

Referring to fig. 3, the detection module 2 has at least one light receiving position 21, and the light receiving position 21 is used for receiving infrared light emitted from the light source module 1 and passing through the gas chamber 311. Correspondingly, the light source module 1 can emit a corresponding number of infrared light beams, and meanwhile, the inspection module having a plurality of light path receiving positions 21 can receive a plurality of infrared light beams, and then detect the average value of the gas concentration of the target gas according to the intensity of the infrared light beams of different light beams, so that the detected gas concentration value of the target gas is more accurate.

Specifically, the gas chamber 311 communicates with the outside, and performs gas exchange with the outside through the waterproof breathable film 4. When the concentration of a certain gas in the target environment needs to be detected, the sensor is placed in the target environment, the gas chamber 311 in the sensor can exchange gas with the outside through the waterproof breathable film 4, and meanwhile, water vapor in the target environment can be prevented from entering the gas chamber 311, so that the detection result is influenced.

Specifically, the shell is provided with a through hole for gas exchange with the outside, the waterproof breathable film 4 covers the through hole, and the waterproof breathable film 4 and the shell 31 are sealed by an O-shaped ring.

Optionally, the housing 31 is made of metal.

Preferably, the first reflecting end surface of the first reflecting member 32, the first reflecting wall of the housing 31, the second reflecting wall of the annular plate 33, the reflecting arc surface of the second reflecting member 34, and the second reflecting end surface of the third reflecting member 35 are plated with a metal having high reflectivity, such as gold, silver, copper, aluminum, etc.

As an embodiment of the invention, the sensor further comprises a PCB and a pin 5 electrically connected with the PCB, the detection module 2 is arranged on the PCB, and the pin 5 is used for installing the sensor at a specified position. Preferably, a communication module for communicating with the outside is further arranged on the PCB, and the communication module communicates with the outside through the contact pin 5.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing detailed description, or equivalent changes may be made in some of the features of the embodiments. All equivalent structures made by using the contents of the specification and the attached drawings of the invention can be directly or indirectly applied to other related technical fields, and are also within the protection scope of the patent of the invention.