Particulate matter concentration detection module

Abstract

This utility model discloses a particulate matter concentration detection module, including a housing, a detection element, a fan, and a circuit board. The housing has an air inlet channel, a beam channel, and an exhaust channel. The air inlet channel and the beam channel intersect and connect to the exhaust channel. The housing also has an air inlet and an exhaust outlet, with the air inlet connected to the air inlet channel and the exhaust outlet connected to the exhaust channel. The detection element includes a light emitter and a light receiver. The light emitter emits a light beam along the beam channel, and the light receiver is located at the intersection of the air inlet channel and the beam channel. The fan is located inside the housing and is used to introduce external airflow into the air inlet through the air inlet and to discharge the airflow entering the exhaust channel through the exhaust outlet. The circuit board is located in the housing, and the detection element and / or the fan are electrically connected to the circuit board. This utility model's particulate matter concentration detection module can improve the update frequency of particulate matter detection results and enhance the real-time detection effect of the particulate matter concentration detection module.

Description

Technical Field

[0001] This utility model relates to the field of particulate matter concentration detection technology, specifically, to a particulate matter concentration detection module. Background Technology

[0002] A laser dust concentration detection device is a device that uses MIE scattering theory to count or measure the mass concentration of suspended particles in the air. A typical dust concentration detection device includes a fluid flow channel, a laser emitting component to generate laser light, and a laser detection component to sense the scattered light. The fluid to be tested flows in the fluid flow channel. When dust particles in the fluid flow over the laser detection component, they are irradiated by the laser, generating scattered light. The laser detection component receives the scattered light and analyzes it to determine the dust concentration in the fluid. In related technologies, the airflow is irradiated by the beam at the intersection of the beam channel and the airflow channel. However, there is a windbreak structure at the entrance of the intersection. After the airflow passes through the windbreak structure and enters the intersection, the flow velocity slows down, and dust accumulates at the intersection, failing to accurately reflect the particulate matter concentration in the airflow. Utility Model Content

[0003] The purpose of this invention is to provide a particulate matter concentration detection module to solve the above-mentioned technical problems.

[0004] The particulate matter concentration detection module proposed in this utility model includes a housing, a detection element, a fan, and a circuit board. The housing has an air inlet channel, a beam channel, and an exhaust channel. The air inlet channel and the beam channel intersect and then communicate with the exhaust channel. The housing also has an air inlet and an exhaust outlet. The air inlet communicates with the air inlet channel, and the exhaust outlet communicates with the exhaust channel. The detection element includes a light emitter and a light receiver. The light emitter emits a light beam along the beam channel, and the light receiver is located at the intersection of the air inlet channel and the beam channel. The fan is located inside the housing and is used to introduce external airflow into the air inlet through the air inlet and to discharge the airflow entering the exhaust channel through the exhaust outlet. The circuit board is located in the housing, and the detection element and / or the fan are electrically connected to the circuit board.

[0005] According to one embodiment of the present invention, a detection bracket is provided inside the housing, a beam channel is provided on the detection bracket, the emitting end of the light emitter faces the entrance of the beam channel, a clearance groove is provided on the detection bracket, the clearance groove forms the intersection of the air intake channel and the beam channel, a clearance hole is provided on the bottom surface of the clearance groove, and a light receiver is provided on the circuit board and aligned with the clearance hole.

[0006] According to one embodiment of the present invention, the detection bracket includes a bracket body for supporting a light emitter. The detection bracket is also provided with two or more filter structures located on the light transmission line of the bracket body. The two or more filter structures are spaced apart, and each filter structure is provided with a filter hole. On the light transmission line, the clearance groove is located downstream of the filter structure.

[0007] According to one embodiment of the present invention, along the direction of light transmission, a light-blocking plate and a light trap structure located downstream of the light-blocking plate are provided on the rear side of the clearance groove. The light-blocking plate is provided with a light-transmitting hole, and the light beam passing through the clearance groove passes through the light-transmitting hole and enters the light trap structure.

[0008] According to one embodiment of the present invention, an extension plate extends along the transmission direction of the light beam on one side of the light-blocking plate, and an extinction structure is provided on the extension plate. A reflector extends to the other side of the light-blocking plate on the housing, and the reflector forms an angle of less than 90° with the light-blocking plate. The light-blocking plate, the reflector, and the extension plate form a light trap structure.

[0009] According to one embodiment of the present invention, the matting structure is a serrated structure provided on the extension plate.

[0010] According to one embodiment of the present invention, the housing is provided with a mounting position for accommodating the detection bracket. The shape of the mounting position is adapted to the detection bracket, and the detection bracket is disposed on the circuit board and placed in the mounting position.

[0011] According to one embodiment of the present invention, the air intake channel and the air exhaust channel are located on both sides of the circuit board. After the circuit board is installed in the housing, the gap between the side of the circuit board away from the air intake channel and the housing forms the air exhaust channel.

[0012] According to one embodiment of the present invention, the air intake channel is located on one side of the mounting position, and a groove is provided on the other side of the mounting position. The part of the circuit board corresponding to the groove is provided with an air passage hole. The airflow in the air intake channel enters the groove after passing through the intersection of the air intake channel and the beam channel, and then enters the exhaust channel through the air passage hole.

[0013] According to one embodiment of the present invention, the housing includes a main body, an upper cover and a lower cover, an air intake channel, a beam channel and an exhaust channel are provided on the main body, the upper cover and the lower cover are respectively provided on both sides of the main body, and the upper cover is provided with an air intake port and an exhaust port.

[0014] Compared with the prior art, the particulate matter concentration detection module of this utility model has the following advantages:

[0015] The particulate matter concentration detection module of this utility model has a confluence groove formed at the intersection of the air intake channel and the beam channel. The confluence groove includes a first bottom wall and a first groove wall and a second groove wall arranged opposite to each other. The first bottom wall connects one side of the first groove wall and one side of the second groove wall. In this way, the confluence is formed only by the first bottom wall, the first groove wall and the second groove wall, thereby eliminating the need for other windproof structures, reducing the obstruction to the airflow passing through the confluence, allowing the measured airflow to maintain its original flow velocity through the confluence, avoiding the deposition of particulate matter at the confluence, and ensuring the detection effect of the particulate matter concentration detection module. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the particulate matter concentration detection module of this utility model;

[0017] Figure 2 This is a schematic diagram of the particulate matter concentration detection module of this utility model from another direction;

[0018] Figure 3 This is an exploded view of the particulate matter concentration detection module of this utility model;

[0019] Figure 4 This is a schematic diagram of the internal structure of the particulate matter concentration detection module of this utility model;

[0020] Figure 5 This is a schematic diagram of the internal structure of another embodiment of the particulate matter concentration detection module of this utility model;

[0021] Figure 6 This is a schematic diagram of the internal structure of another embodiment of the particulate matter concentration detection module of this utility model;

[0022] Figure 7 This is a schematic diagram of the detection bracket in this utility model.

[0023] In the diagram: a. Intake channel, b. Beam channel, c. Exhaust channel, 1. Housing, 11. Intake port, 12. Exhaust port, 2. Detection element, 21. Light emitter, 22. Light receiver, 3. Fan, 4. Circuit board, 5. Detection bracket, 51. Clearance groove, 511. Clearance hole, 52. Bracket body, 53. Filter structure, 531. Filter hole, 54. Light blocking plate, 541. Light transmission hole, 55. Extension plate, 551. Extinction structure, 13. Reflector, 14. Mounting position, 15. Slot, 41. Vent hole, 1a. Main body, 1b. Top cover, 1c. Bottom cover.

[0024] The implementation and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0026] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0027] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a 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 utility model.

[0028] To further understand the content, features, and effects of this utility model, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings:

[0029] This utility model discloses a particulate matter concentration detection module. Please refer to [link / reference]. Figures 1 to 6 The particulate matter concentration detection module proposed in this utility model includes a housing 1, a detection element 2, a fan 3, and a circuit board 4. The housing 1 has an air inlet channel a, a beam channel b, and an exhaust channel c. The air inlet channel a and the beam channel b intersect and then communicate with the exhaust channel c. The housing 1 is also provided with an air inlet 11 and an exhaust outlet 12. The air inlet 11 communicates with the air inlet channel a, and the exhaust outlet 12 communicates with the exhaust channel c. The detection element 2 includes a light emitter 21 and a light receiver 22. The light emitter 21 emits a light beam along the beam channel b, and the light receiver 22 is located at the intersection of the air inlet channel a and the beam channel b. The fan 3 is located inside the housing 1 and is used to introduce external airflow into the air inlet 11 and to discharge the airflow entering the exhaust channel c through the exhaust outlet 12. The circuit board 4 is located on the housing 1, and the detection element 2 and / or the fan 3 are electrically connected to the circuit board 4.

[0030] In this embodiment, the air inlet 11 allows the measured airflow to flow into the air inlet channel a, and the exhaust port 12 allows the measured airflow to flow out of the exhaust channel c. After flowing into the air inlet channel a from the air inlet 11, the measured airflow will flow through the exhaust channel c and then out of the exhaust port 12. The fan 3 is used to drive the measured fluid to flow along a preset path. The circuit board 4 can provide power to the fan 3 and the detection element 2 and distribute electrical signals.

[0031] The light emitter 21 emits a laser beam along the beam channel b. Since the beam channel b intersects with the air intake channel a, the laser beam enters the air intake channel a along the beam channel b. The beam entering the air intake channel a irradiates the fluid being measured flowing through the intersection of the air intake channel a and the beam channel b, generating scattered light. Part of the scattered light is received by the light receiver 22 installed at the intersection of the air intake channel a and the beam channel b. The light receiver 22 converts the received scattered light into an electrical signal. The signal adjustment circuit on the circuit board 4 amplifies the signal, performs noise reduction, and then sends the detection result to the processing unit. The processing unit calculates the dust concentration in the fluid being measured based on the processed detection signal.

[0032] The intersection of the air intake channel a and the beam channel b forms an intersection groove. The intersection groove includes a first bottom wall and a first groove wall and a second groove wall arranged opposite to each other. The first bottom wall connects one side of the first groove wall to one side of the second groove wall. In this way, the intersection is formed only by the first bottom wall, the first groove wall and the second groove wall, thereby eliminating the need for other windproof structures, reducing the obstruction to the airflow passing through the intersection, and allowing the measured airflow to maintain its original flow velocity through the intersection. The wall particles are deposited at the intersection to improve the accuracy of the particle detection results.

[0033] The particulate matter concentration detection module of this utility model, such as Figures 3 to 7 As shown, a detection bracket 5 is provided inside the housing 1, and a beam channel b is provided on the detection bracket 5. The emitting end of the light emitter 21 faces the entrance of the beam channel b. A clearance groove 51 is provided on the detection bracket 5. The clearance groove 51 forms the intersection of the air intake channel a and the beam channel b. A clearance hole 511 is provided on the bottom surface of the clearance groove 51. The light receiver 22 is provided on the circuit board 4 and is aligned with the clearance hole 511.

[0034] The detection bracket 5 forms a beam channel b. A light emitter 21 is installed at the entrance of the beam channel b. The beam emitted by the light emitter 21 can enter the clearance groove 51 along the beam channel b. The clearance groove 51 forms a partial air intake channel a, which is located on the flow path of the measured airflow. As the measured airflow flows from the air inlet 11 to the exhaust channel c, it passes through the clearance groove 51. Therefore, the beam entering the clearance groove 51 will irradiate the measured airflow flowing through the clearance groove 51, generating scattered light. Some of the scattered light will enter the clearance hole 511 and is finally received by the light receiver 22, which is aligned with the clearance hole 511. The detection bracket 5 ensures that the beam emitted by the light emitter 21 can stably enter the clearance groove 51, that is, the intersection of the air intake channel a and the beam channel b, thus ensuring that the beam can irradiate the measured airflow flowing through the clearance groove 51.

[0035] The particulate matter concentration detection module of this utility model, such as Figure 7 As shown, the detection bracket 5 includes a bracket body 52, which supports the light emitter 21. The detection bracket 5 is also provided with two or more filter structures 53 located on the light transmission path of the bracket body 52. ​​The two or more filter structures 53 are spaced apart, and each filter structure 53 is provided with a filter hole 531. On the light transmission path, the clearance groove 51 is located downstream of the filter structure 53.

[0036] Two or more filter structures 53 are spaced apart along the optical transmission line. The filter structure 53 can perform two or more levels of filtering on the light beam emitted by the light emitter 21, thereby filtering out excess light beams that are not preset wavelength, not preset intensity, or divergent, and only retaining the preset center light beam through the filter hole 531. After two or more levels of filtering, the light beam can finally enter the clearance groove 51 located downstream of the filter structure 53. In this way, the intensity, wavelength, or incident angle of the light beam entering the clearance groove 51 can be more uniform, so that the scattered light received by the light receiver 22 is also more uniform, and the detection result of the dust concentration in the measured fluid calculated from the scattered light is more accurate and reliable.

[0037] The particulate matter concentration detection module of this utility model, such as Figures 5 to 7 As shown, along the direction of light transmission, a light-blocking plate 54 and a light trap structure located downstream of the light-blocking plate 54 are provided on the rear side of the clearance groove 51. The light-blocking plate 54 is provided with a light-transmitting hole 541. The light beam passing through the clearance groove 51 passes through the light-transmitting hole 541 and enters the light trap structure.

[0038] The light trap structure is used to reduce the reflected light generated when the light beam emitted by the light emitter 21 passes through the avoidance groove 51 and shines on the side wall of the housing 1, which then enters the avoidance groove 51 again, generating new scattered light that is received by the light receiver 22 and affects the detection results.

[0039] When the light beam emitted by the light emitter 21 enters the light trap structure through the light-transmitting hole 541, it will illuminate the side wall of the light trap structure and be reflected. The emitted light will be blocked by the light-blocking plate 54 and will be difficult to shine through the relief groove 51, thereby avoiding the generation of new scattered light that will be received by the light receiver 22 and affect the detection results.

[0040] The particulate matter concentration detection module of this utility model, such as Figures 5 to 7 As shown, an extension plate 55 extends along the transmission direction of the light beam on one side of the light-blocking plate 54. An extinction structure 551 is provided on the extension plate 55. A reflector 13 extending to the other side of the light-blocking plate 54 is provided on the housing 1. The reflector 13 and the light-blocking plate 54 form an angle of less than 90°. The light-blocking plate 54, the reflector 13 and the extension plate 55 form a light trap structure.

[0041] The light-blocking plate 54, reflector 13, and extension plate 55 form a triangular light trap structure. The surface of the reflector 13 forms an angle with the surface of the light-blocking plate 54. The light beam entering the light trap structure first hits the reflector 13, and most of the light is then reflected onto the extinction structure 551 of the extension plate 55. The extinction structure 551 includes at least one protrusion, which can reflect the reflected light generated by the light-blocking plate 551 again. Through multiple reflections, most of the reflected light can be canceled out. Very little reflected light re-enters the clearance groove 51 through the light-transmitting hole 541. Therefore, interference light on the detection results can be reduced, and the accuracy of the detection results can be improved.

[0042] The reflector 13 of the light trap structure is formed by the inner wall of the housing 1 instead of the detection bracket 5. This simplifies the shape of the detection bracket 5 and increases the distance between the reflector 13 and the light-transmitting hole 541, making it more difficult for the light reflected by the reflector 13 to reach the light-transmitting hole 541. This further reduces the interference of interfering light on the detection results and further improves the accuracy of the detection results.

[0043] The particulate matter concentration detection module of this utility model, such as Figures 5 to 7 As shown, the extinction structure 551 is a serrated structure disposed on the extension plate 55. The extinction structure 551 may be composed of multiple continuously arranged protrusions, the protrusions being triangular, so that the combined extinction structure 551 is serrated. The serrated extinction structure 551 can improve the extinction effect after light irradiation, canceling out more reflected light, thereby further reducing the interference of interfering light on the detection results and further improving the accuracy of the detection results.

[0044] The particulate matter concentration detection module of this utility model, such as Figure 3 As shown, the housing 1 is provided with a mounting position 14 for accommodating the detection bracket 5. The shape of the mounting position 14 is adapted to the detection bracket 5. The detection bracket 5 is disposed on the circuit board 4 and placed in the mounting position 14.

[0045] The testing bracket 5 can be adapted and installed within the mounting position 14, thereby improving the installation stability of the testing bracket 5 within the housing 1, reducing the idle space within the housing 1, and improving the effective utilization of the space within the housing 1. The testing bracket 5 is connected to the circuit board 4, providing support for the circuit board 4, and the circuit board 4 can also position the testing bracket 5.

[0046] The particulate matter concentration detection module of this utility model, such as Figures 1 to 3 As shown, the intake channel a and the exhaust channel c are located on both sides of the circuit board 4. After the circuit board 4 is installed in the housing 1, the gap between the side of the circuit board 4 away from the intake channel a and the housing 1 forms the exhaust channel c.

[0047] The housing 1 has a first sidewall and a second sidewall that are arranged opposite to each other along the thickness direction. The two surfaces of the circuit board 4 are opposite to the first sidewall and the second sidewall, respectively. The air intake channel a is located between the first sidewall and the circuit board 4, and the exhaust channel c is located between the second sidewall and the circuit board 4.

[0048] The particulate matter concentration detection module of this utility model, such as Figures 3 to 6 As shown, the air intake channel a is located on one side of the mounting position 14, and the other side of the mounting position 14 is provided with a recess 15. The part of the circuit board 4 corresponding to the recess 15 is provided with an air passage 41. The airflow in the air intake channel a enters the recess 15 after passing through the intersection of the intake channel a and the beam channel b, and then enters the exhaust channel c through the air passage 41.

[0049] The air passage 41 connects the air intake channel a and the exhaust channel c. The airflow flowing into the air intake channel a from the air intake port 11 flows through the test bracket 5 installed at the mounting position 14 and then flows into the exhaust channel c located on the other side of the circuit board 4 through the air passage 41 at the sink 15. The sink 15 can ensure that the airflow has a certain buffer space before flowing into the air passage 41, preventing the airflow from becoming turbulent at the air passage 41.

[0050] The particulate matter concentration detection module of this utility model, such as Figures 3 to 7 As shown, the housing 1 includes a main body 1a, an upper cover 1b and a lower cover 1c. An air intake channel a, a beam channel b and an exhaust channel c are provided on the main body 1a. The upper cover 1b and the lower cover 1c are respectively provided on both sides of the main body 1a. An air intake port 11 and an exhaust port 12 are provided on the upper cover 1b.

[0051] The upper cover 1b and the lower cover 1c are opposite each other along the thickness direction of the main body 1a. The circuit board 4 is located between the upper cover 1b and the lower cover 1c. The air inlet channel a is located between the circuit board 4 and the lower cover 1c, and the exhaust channel c is located between the circuit board 4 and the upper cover 1b. The circuit board 4 has a clearance notch opposite to the air inlet 11. The fan 3 is installed at the clearance notch. The air inlet side of the fan 3 is connected to the air inlet 11, and the air outlet side of the fan 3 is connected to the air inlet channel a. Thus, when the fan 3 is working, it can blow external airflow from the air inlet 11 to the air inlet channel a, and then the airflow flows from the air inlet channel a to the exhaust channel c, and finally flows out from the exhaust port 12. By opening both the air inlet 11 and the exhaust port 12 on the upper cover 1b, when installing the particulate matter concentration detection module in the application device, it is only necessary to keep the parts of the upper cover 1b with the air inlet 11 and the exhaust port 12 unobstructed, without exposing the main body 1a and the lower cover 1c, thereby simplifying the installation method of the particulate matter concentration detection module.

[0052] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A particulate matter concentration detection module, characterized by, include: The housing (1) has an air intake channel (a), a beam channel (b) and an exhaust channel (c). The air intake channel (a) and the beam channel (b) intersect and are connected to the exhaust channel (c). The housing (1) is also provided with an air inlet (11) and an exhaust outlet (12). The air inlet (11) is connected to the air intake channel (a), and the exhaust outlet (12) is connected to the exhaust channel (c). The detection element (2) includes a light emitter (21) and a light receiver (22), wherein the light emitter (21) emits a light beam along the beam channel (b), and the light receiver (22) is located at the intersection of the air intake channel (a) and the beam channel (b); A fan (3), which is located inside the housing (1), is used to introduce external airflow into the air inlet (11) through the air inlet (11) and to discharge the airflow that enters the exhaust channel (c) through the exhaust port (12); A circuit board (4) is disposed in the housing (1), and the detection element (2) and / or fan (3) are electrically connected to the circuit board (4).

2. The particulate matter concentration detection module of claim 1, wherein, The housing (1) is provided with a detection bracket (5), the beam channel (b) is provided on the detection bracket (5), the emitting end of the light emitter (21) faces the entrance of the beam channel (b), the detection bracket (5) is provided with a clearance groove (51), the clearance groove (51) forms the intersection of the air intake channel (a) and the beam channel (b), the bottom surface of the clearance groove (51) is provided with a clearance hole (511), and the light receiver (22) is provided on the circuit board (4) and aligned with the clearance hole (511).

3. The particulate matter concentration detection module of claim 2, wherein, The detection bracket (5) includes a bracket body (52) for supporting the light emitter (21). The detection bracket (5) is also provided with two or more filter structures (53) located on the light transmission line of the bracket body (52). The two or more filter structures (53) are spaced apart. Each filter structure (53) is provided with a filter hole (531). On the light transmission path, the clearance groove (51) is located downstream of the filter structure (53).

4. The particulate matter concentration detection module according to claim 2, characterized in that, Along the direction of light transmission, a light-blocking plate (54) and a light trap structure located downstream of the light-blocking plate (54) are provided on the rear side of the clearance groove (51). The light-blocking plate (54) is provided with a light-transmitting hole (541). The light beam passing through the clearance groove (51) passes through the light-transmitting hole (541) and enters the light trap structure.

5. The particulate matter concentration detection module according to claim 4, characterized in that, An extension plate (55) extends along the transmission direction of the light beam on one side of the light-blocking plate (54). An extinction structure (551) is provided on the extension plate (55). A reflector (13) extending to the other side of the light-blocking plate (54) is provided on the housing (1). The reflector (13) and the light-blocking plate (54) form an angle of less than 90°. The light-blocking plate (54), the reflector (13) and the extension plate (55) form the light trap structure.

6. The particulate matter concentration detection module according to claim 5, characterized in that, The matting structure (551) is a serrated structure provided on the extension plate (55).

7. The particulate matter concentration detection module according to claim 2, characterized in that, The housing (1) is provided with a mounting position (14) for accommodating the detection bracket (5). The shape of the mounting position (14) is adapted to the detection bracket (5). The detection bracket (5) is disposed on the circuit board (4) and placed in the mounting position (14).

8. The particulate matter concentration detection module according to claim 7, characterized in that, The intake channel (a) and the exhaust channel (c) are located on both sides of the circuit board (4). After the circuit board (4) is installed in the housing (1), the gap between the side of the circuit board (4) away from the intake channel (a) and the housing (1) forms the exhaust channel (c).

9. The particulate matter concentration detection module according to claim 8, characterized in that, The air intake channel (a) is located on one side of the mounting position (14), and a groove (15) is provided on the other side of the mounting position (14). The part of the circuit board (4) corresponding to the groove (15) is provided with an air passage hole (41). The airflow in the air intake channel (a) enters the groove (15) after passing through its intersection with the beam channel (b), and then enters the exhaust channel (c) through the air passage hole (41).

10. The particulate matter concentration detection module according to claim 1, characterized in that, The housing (1) includes a main body (1a), an upper cover (1b) and a lower cover (1c). The air intake channel (a), the beam channel (b) and the exhaust channel (c) are provided on the main body (1a). The upper cover (1b) and the lower cover (1c) are respectively provided on both sides of the main body (1a). The upper cover (1b) is provided with the air intake port (11) and the exhaust port (12).

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