Dual-channel air quality sensor

Abstract

A dual-channel air quality sensor, comprising an upper cover (1), a lower cover (4), a middle cover (3), and a PCBA board (2). The middle cover (3) and the PCBA board (2) are located between the upper cover (1) and the lower cover (4); an interior air duct and an exterior air duct are provided on the middle cover (3); two blower wheels (6) are integrated on the PCBA board (2); the two blower wheels (6) are respectively located in the interior air duct and the exterior air duct; several sensors are provided in both the interior air duct and the exterior air duct; and all the sensors are integrated on the PCBA board (2). The blower wheels (6) are integrated on the PCBA board (2), wherein each blower wheel (6) comprises a stator, an impeller (661), a bearing (642), and associated accessories. Compared with a traditional blower solution, the present invention omits parts such as a PCB, a chip, and a wire harness, and the blower wheels (6) and the sensors are all integrated on one PCBA board (2), thereby exhibiting the characteristics of a high integration level, a small size, few parts, and low cost.

Description

Dual-channel air quality sensor TECHNICAL FIELD

[0001] The present application relates to the field of gas detection sensors, in particular to a dual-channel air quality sensor. BACKGROUND

[0002] With the improvement of people's quality of life, many cars are equipped with dual-channel PM2.5 sensors to measure the PM2.5 concentration inside and outside the car. Through the air conditioning system, air filtration or switching of the internal and external circulation modes of the air conditioner is achieved to avoid the pollution of the air inside the car and ensure the fresh air of the driving environment. However, the current dual-channel sensor uses two independent fans, each fan contains a fan blade, a stator, a PCB, a chip, a volute, etc. The fan is assembled below the air duct, which has a complex structure, complex process, large volume and high cost. In addition, the market is dominated by single-function PM2.5 sensors, which have few functions and low integration.

[0003] SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a dual-channel air quality sensor which simplifies the installation method of the fan, has a compact structure and fewer parts. To achieve the above-mentioned purpose, the present application is realized by the following technical solutions:

[0005] A dual-channel air quality sensor comprises an upper cover, a lower cover, a middle cover and a PCBA board, the middle cover and the PCBA board are located between the upper cover and the lower cover, the middle cover is provided with an indoor air duct and an outdoor air duct, the PCBA board is integrated with two air wheels, the two air wheels are located in the indoor air duct and the outdoor air duct respectively, a plurality of sensors are arranged in the indoor air duct and the outdoor air duct, and all the sensors are integrated on the PCBA board.

[0006] Further, the PCBA board is provided with a copper middle tube mounting hole and two coil pin mounting holes corresponding to the position of each air wheel, the copper middle tube of each air wheel is inserted into the corresponding copper middle tube mounting hole of the PCBA board and fixedly connected with the PCBA board, the coil frame of each air wheel is provided with two coil pins connected with the coil, and each coil pin is inserted into the corresponding coil pin mounting hole of the PCBA board and welded with the PCBA board, and the PCBA board controls the opening of the two air wheels.

[0007] Further, the surface of the copper middle tube is provided with a concave-convex structure to increase the surface roughness of the copper middle tube, and the copper middle tube is fixed with the PCBA board by glue.

[0008] Further, the middle cover side is provided with an indoor air inlet, an indoor air outlet, an outdoor air inlet and an outdoor air outlet; the lower cover is internally provided with a first sealing rib and a second sealing rib, the first sealing rib and the second sealing rib respectively surround a first closed area and a second closed area, and the first sealing rib and the second sealing rib are tightly attached to the bottom surface of the middle cover; the indoor air duct comprises a first air wheel cavity and a first air duct which are isolated from each other, the first air duct is communicated with the outdoor air inlet, the first air wheel cavity is communicated with the outdoor air outlet, the first air wheel cavity is provided with a first air inlet at the bottom, the first air duct is provided with a first air outlet at the bottom, and the first air outlet and the first air inlet are communicated with the first closed area in the lower cover; the outdoor air duct comprises a second air wheel cavity and a second air duct which are isolated from each other, the second air duct is communicated with the outdoor air inlet, the second air wheel cavity is communicated with the outdoor air outlet, the second air wheel cavity is provided with a second air inlet at the bottom, the second air duct is provided with a second air outlet at the bottom, and the second air outlet and the second air inlet are communicated with the second closed area in the lower cover; two air wheels are respectively arranged in the first air wheel cavity and the second air wheel cavity.

[0009] Further, the coil holder of each air wheel is provided with two positioning blocks of different sizes, the PCBA board is provided with two air wheel positioning holes of different sizes, the two air wheel positioning holes correspond to the two positioning blocks one by one, the positioning blocks are inserted into the corresponding air wheel positioning holes to position the air wheel stator and prevent mistakes; the positioning blocks are in a stepped shape, the PCBA board is placed on the stepped surface of the positioning blocks to ensure that the upper surface of the air wheel has a certain gap with the PCBA board, so as to prevent collision.

[0010] Further, the bottom surface of the middle cover is rubberized at positions corresponding to the first sealing rib and the second sealing rib, and the rubberized parts are tightly attached to the first sealing rib and the second sealing rib.

[0011] Further, the side of the middle cover close to the PCBA board is rubberized, the outdoor air duct is located in the rubberized area, and the PCBA board presses the rubberized part on the middle cover.

[0012] Further, the PCBA board is provided with two different types of connectors, and any one connector can supply power and transmit signals to the PCBA board.

[0013] Further, the lower cover is internally provided with a plurality of screw mounting columns, the middle cover and the PCBA board are provided with through holes corresponding to the screw mounting columns, and the screws are locked on the corresponding threaded hole columns of the lower cover after passing through the through holes of the middle cover and the PCBA board, so that the middle cover, the lower cover and the PCBA board are connected by the screws.

[0014] Further, the PCBA board is provided with a plurality of PCBA positioning holes, the middle cover is internally provided with a plurality of PCBA positioning columns, the PCBA positioning columns are inserted into the corresponding PCBA positioning holes to determine the relative position of the PCBA board and the middle cover, and ensure the accurate position of the air wheel at the volute of the middle cover, so as to have higher suction force.

[0015] The vehicle-mounted double-channel air quality sensor has the following beneficial effects:

[0016] 1. The wind wheel is integrated on the PCBA, and the wind wheel comprises a stator, a fan blade, a bearing and its accessories, compared with the traditional fan scheme, the PCBA, the chip and the wire harness are omitted;

[0017] 2. The volute is integrated on the middle cover, and the thickness of the fan can be omitted in volume;

[0018] 3. The middle shell adopts a rubber coating design, which can completely seal the vehicle outside channel after assembly, preventing mutual air leakage between the inside and outside of the vehicle and affecting the measurement accuracy;

[0019] 4. The lower cover and the middle cover are sealed, the air duct design is optimized, a negative pressure area is generated below the centrifugal fan, and better air suction effect is achieved;

[0020] 5. The screw passes through the middle cover and the PCBA and is locked to the lower cover, the number of parts is small, the assembly is more convenient, and the process is simple;

[0021] 6. In addition to the PM2.5 function in the vehicle air duct, carbon dioxide, temperature and humidity, TVOC, etc. can be added, and the AQS sensor function can be added in the vehicle air duct;

[0022] 7. The fan and the sensors are integrated on one PCBA, which has the characteristics of high integration, small size, few parts and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is an exploded view of the double-channel air quality sensor of the embodiment of the application;

[0024] Fig. 2 is a view of the fan, the sensors and the connector mounted on the PCBA board, and Fig. 2 is a view from the bottom angle of Fig. 1;

[0025] Fig. 3 is an exploded view of the components of Fig. 2;

[0026] Fig. 4 is a schematic view of the fan, the sensors and the connector in the middle cover;

[0027] Fig. 5 is a bottom view of the middle cover with the fan installed;

[0028] Fig. 6 is an exploded view of the fan;

[0029] Fig. 7 is another exploded view of the fan. DETAILED DESCRIPTION

[0030] The application will be further described below in conjunction with the drawings and embodiments.

[0031] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0032] As shown in FIGS. 1-7, a double-channel air quality sensor includes an upper cover 1, a lower cover 4, a middle cover 3 and a PCBA board 2, the middle cover 3 and the PCBA board 2 are installed between the upper cover 1 and the lower cover 4.

[0033] The upper cover 1 and the lower cover 4 are connected by a buckle structure, specifically, the upper cover 1 is provided with a clamping groove around, the lower cover 4 is provided with a clamping block around, the upper cover 1 is detachably connected with the lower cover 4 through the matched clamping block and clamping groove. The clamping groove can also be arranged on the lower cover 4, and the clamping block can be arranged on the upper cover 1. The upper cover 1 and the lower cover 4 can also be connected by screws, welding or adhesion.

[0034] The lower cover 4 is provided with a first sealing rib 41 and a second sealing rib 42 on the side close to the middle cover 3, both the first sealing rib 41 and the second sealing rib 42 are closed shapes, and form a first closed area 43 and a second closed area 44 respectively.

[0035] The middle cover 3 is provided with an indoor air inlet 31, an indoor air outlet 32, an outdoor air inlet 33 and an outdoor air outlet 34, and is provided with a first air wheel cavity 35, a first air duct 36, a second air wheel cavity 39 and a second air duct 310. The middle cover 3 is provided with a first air inlet 37 and a first air outlet 38 corresponding to the position of the first closed area 43 in the lower cover 4, and is provided with a second air inlet 311 and a second air outlet 312 corresponding to the position of the second closed area 44 in the lower cover 4. The first air wheel cavity 35 and the second air wheel cavity 39 are both volute structures.

[0036] The first wind wheel cavity 35 is connected with the vehicle-outlet air outlet 34, the first air inlet 37 is located on the bottom surface of the first wind wheel cavity 35, and the first wind wheel cavity 35 is connected with the first closed area 43 through the first air inlet 37. The first air duct 36 is connected with the vehicle-inlet air inlet 33, the first air outlet 38 is located on the bottom surface of the first air duct 36, and the first air duct 36 is connected with the first closed area 43 through the first air outlet 38. The first air duct 36 and the first wind wheel cavity 35 are connected to form a vehicle-outlet air duct. In order to ensure the sealing performance of the vehicle-outlet air duct and ensure the accuracy of detection, the junction between the vehicle-outlet air duct and the PCBA board is sealed by the glue 5. Similarly, the second wind wheel cavity 39 is connected with the vehicle-inlet air outlet 32, the second air inlet 311 is located on the bottom surface of the second wind wheel cavity 39, and the second wind wheel cavity 39 is connected with the second closed area 44 through the second air inlet 311; the second air duct 310 is connected with the vehicle-inlet air inlet 33, the second air outlet 312 is located on the bottom surface of the second air duct 310, and the second air duct 310 is connected with the second closed area 44 through the second air outlet 312. The second air duct 310 and the second wind wheel cavity 39 are connected to form a vehicle-inlet air duct.

[0037] The PCBA board 2 is provided with a carbon dioxide installation site, a laser module installation site, a shielding cover installation site, and two wind wheel installation sites. Each wind wheel installation site is provided with a wind wheel 6, and the two wind wheels 6 are respectively arranged in the first wind wheel cavity 35 and the second wind wheel cavity 39. The first closed area 43 and the second closed area 44 respectively form a negative pressure area with a certain height below the two wind wheels 6.

[0038] As shown in FIGS. 3 and 4, the carbon dioxide installation site is fixed with a gas cavity shell 24, and the electronic devices such as a lamp stack in the gas cavity shell 24 form a carbon dioxide sensor. The PM2.5 dust sensor installation site is assembled with a laser module 27 and a shielding cover. The wind wheel 6, the carbon dioxide sensor, the laser module, and the shielding cover are all located on the side of the PCBA board 2 facing the middle cover 3, and the middle cover 3 is provided with a groove or a cavity corresponding to the positions of the wind wheel 6, the carbon dioxide sensor, the laser module 27, and the shielding cover. A plurality of sensors are installed on the PCBA board 2 as needed, for example, the PCBA board 2 is provided with a carbon dioxide sensor, a temperature and humidity sensor 28, and an AQS sensor 26, etc. The vehicle-inlet air duct can detect carbon dioxide, temperature and humidity, TVOC, etc. in addition to the PM2.5 detection function, and the AQS sensor 26 can be arranged in the vehicle-outlet air duct. All the sensors and the wind wheel 6 are integrated on the PCBA board 2, which has the advantages of high integration, small size, and few parts.

[0039] In this embodiment, the first air duct 36 is provided with an AQS sensor 26, a laser module 27, a shielding cover, and a rubber coating 5 on the side of the middle cover 3 close to the PCBA board 2. The AQS sensor 26, the laser module 27, the shielding cover, the first air duct 36, and the first air wheel cavity 35 are all located in the rubber coating 5 area (i.e., the out-of-vehicle air duct is located in the rubber coating 5 area). The first sealing rib 41 and the second sealing rib 42 of the lower cover 4 are tightly attached to the bottom surface of the middle cover 3. The PCBA board 2 is pressed against the rubber coating 5 on the middle cover 3, ensuring that the out-of-vehicle air duct forms a sealed air duct, preventing the intermixing of indoor and outdoor air and affecting the detection accuracy.

[0040] In this embodiment, the second air duct 310 is provided with a carbon dioxide sensor, a laser module 27, a shielding cover, and a temperature and humidity sensor. These sensors are configured according to the needs and integrated on the PCBA board 2. Other types of sensors can also be added. The PCBA board 2 is also provided with two different types of connectors 23. Either of the two connectors 23 can be used to provide power and transmit signals to the PCBA board 2.

[0041] The PCBA board 2 is provided with a plurality of middle cover positioning holes 25, and the middle cover 3 is provided with a plurality of middle cover positioning columns 313. The middle cover positioning columns 313 are inserted into the corresponding middle cover positioning holes 25 to determine the relative position of the PCBA board 2 and the middle cover 3.

[0042] The lower cover 4 is provided with a plurality of screw mounting columns 45. The middle cover 3 and the PCBA board 2 are provided with through holes corresponding to the positions of the screw mounting columns 45. Screws are used to pass through the through holes on the middle cover 3 and the PCBA board 2 and then locked in the corresponding threaded holes on the lower cover 4, thereby realizing the assembly of the middle cover 3, the PCBA board 2, and the lower cover 4.

[0043] As shown in FIG. 6 and FIG. 7, the fan wheel 6 includes a stator and a rotor, the stator is fixed by the copper-in-tube assembly 64 and the coil stator assembly 65, and the rotor is the fan blade rotor assembly 66. The copper-in-tube assembly 64 includes a copper-in-tube 641 and a bearing 642 installed inside the copper-in-tube 641, and the coil stator assembly 65 includes a coil holder 63, a coil, a silicon steel sheet and a coil pin 61 connected with the enameled wire. The fan blade rotor assembly 66 includes a fan blade 661, a soft magnetic ring 662, a magnetic frame and a central shaft 663. The central shaft 663 of the fan blade rotor assembly 66 is fixed on the bearing 642 of the copper-in-tube assembly 64. The coil pin 61 is welded with the PCBA board 2, and the copper-in-tube 641 is fixedly connected with the PCBA board 2. The PCBA board 2 controls the start of the fan wheel 6 after being powered on, and the stator drives the soft magnetic ring 662 to rotate, thereby driving the fan blade 661 to rotate. The fan wheel 6 is a commonly used part in the field. The fan wheel 6 of the embodiment is different from the conventional fan wheel on the market in that the fan wheel 6 does not have a PCB and a chip inside. The start of the fan wheel 6 is controlled by the PCBA board 2 on the middle cover 3, and the fan wheel 6 does not need to use a wire harness to be powered on. The fan wheel 6 is integrated on the PCBA board 2, compared with the installation scheme of the conventional fan wheel 6, the PCB, the chip, the wire harness and other parts of the conventional fan wheel 6 are omitted, and the connection mode of the fan wheel 6 and the PCBA board 2 is simpler.

[0044] The coil holder 63 of the fan wheel 6 is provided with two coil pins 61 and a plurality of positioning blocks 62. The two coil pins 61 are respectively connected with both ends of the coil, and the two coil pins 61 are respectively inserted into the corresponding pin mounting holes of the PCBA board 2 and welded with the PCBA board 2. The PCBA board 2 is provided with a Hall sensor chip for controlling the fan wheel 6.

[0045] The coil holder 63 of the fan wheel 6 is provided with a plurality of positioning blocks 62, and the PCBA board 2 is provided with a plurality of fan wheel positioning holes 21. The positioning blocks 62 are inserted into the fan wheel positioning holes 21 one by one to position the fan wheel 6. Preferably, the positioning blocks 62 in the embodiment are two, which are respectively located on both sides of the copper-in-tube 641 of the fan wheel 6, and the number of the fan wheel positioning holes 21 is also two. The two positioning blocks 62 are different in size, and each positioning block 62 is inserted into the corresponding fan wheel positioning hole 21 of the PCBA board 2 to prevent mistakes and cause abnormalities such as fan reverse rotation. The positioning block 62 is in a stepped shape, and the PCBA board 2 is placed on the stepped surface of the positioning block 62 to ensure that the upper surface of the fan blade rotor assembly 66 has a certain gap with the PCBA board 2 to prevent collision.

[0046] As shown in FIG. 3, the PCBA board is provided with a copper middle tube mounting hole 22 corresponding to the position of the copper middle tube 641 of each wind wheel 6. The copper middle tube 641 is inserted into the copper middle tube mounting hole 22 on the PCBA board 2 and is fixed and sealed by point gluing. The surface of the copper middle tube 641 is provided with knurling or grooves or other concave-convex structures for increasing the roughness of the surface of the copper middle tube 641. The contact area between the copper middle tube 641 and the glue is increased, so that the connection between the copper middle tube 641 and the PCBA board 2 is more firm after the glue is solidified, and the copper middle tube 641 is not easy to fall off due to vibration.

[0047] The middle cover 3 is provided with an air duct and has a certain thickness. All sensors and wind wheels 6 are integrated on the side of the PCBA board 2 facing the middle cover 3. These components are accommodated in the middle cover 3, so that the side of the PCBA board 2 facing the upper cover 1 is relatively flat. After the PCBA board 2 is installed in the middle cover 3, the top surface of the PCBA board 2 is not higher than the top surface of the middle cover 3 or only slightly protrudes from the top surface of the middle cover 3.

[0048] The middle cover 3 is installed in the cavity of the lower cover 4. The bottom surface of the middle cover 3 is treated by glue wrapping 5 at positions corresponding to the first sealing rib 41 and the second sealing rib 42. The glue wrapping 5 part is in close contact with the first sealing rib 41 and the second sealing rib 42. In the start state of the fan, the first closed area 43 and the second closed area 44 form a sealed negative pressure area.

[0049] The side of the middle cover 3 facing the PCBA board 2 is wrapped with glue 5, and the bottom surface of the middle cover 3 is wrapped with glue 5. By treating the middle cover 3 with glue 5, there is no need to set sealing pads on the upper and lower sides of the middle cover 3, which reduces the number of parts and the assembly steps and is more conducive to automatic assembly.

[0050] The middle cover 3 is in close contact with the first sealing rib 41 and the second sealing rib 42 in the lower cover 4. The PCBA board 2 integrating various sensors and wind wheels 6 is installed in the middle cover 3. After the upper cover 1 and the lower cover 4 are assembled, the thickness of the entire product is only slightly thicker than the thickness of the wind wheel 6. The thickness is thin, the volume is small, and the structure is compact.

[0051] The wind wheel 6 and the various sensors are integrated on the PCBA board 2. Therefore, when assembling, there are only four components, i.e., the upper cover 1, the middle cover 3, the lower cover 4, and the PCBA board 2. The middle cover 3, the lower cover 4, and the PCBA board 2 are assembled together by locking screws, and then the upper cover 1 and the lower cover 4 are buckled, which simplifies the assembly steps.

[0052] The above described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, therefore, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

Claims

1. A dual channel air quality sensor, characterized in that, The application relates to a vehicle air conditioner, which comprises an upper cover, a lower cover, a middle cover and a PCBA board, the middle cover and the PCBA board are located between the upper cover and the lower cover, the middle cover is provided with an indoor air duct and an outdoor air duct, the PCBA board is integrated with two air wheels, the two air wheels are located in the indoor air duct and the outdoor air duct respectively, a plurality of sensors are arranged in the indoor air duct and the outdoor air duct, and all the sensors are integrated on the PCBA board.

2. The dual channel air quality sensor of claim 1, wherein, A copper middle pipe mounting hole and two coil pin mounting holes are arranged on the PCBA board at positions corresponding to each air wheel, the copper middle pipe of each air wheel is inserted into the corresponding copper middle pipe mounting hole on the PCBA board and is fixedly connected with the PCBA board, two coil pins connected with the coil are arranged on the coil bracket of each air wheel, each coil pin is inserted into the corresponding coil pin mounting hole on the PCBA board and is welded with the PCBA board, and the PCBA board controls the opening of the two air wheels.

3. The dual channel air quality sensor of claim 2, wherein, The surface of the copper middle pipe is provided with a concave-convex structure to increase the roughness of the surface of the copper middle pipe, and the copper middle pipe is fixed with the PCBA board through glue.

4. The dual channel air quality sensor of claim 2, wherein, Two different size positioning blocks are arranged on the coil bracket of each air wheel, two different size air wheel positioning holes are arranged on the PCBA board, the two air wheel positioning holes correspond to the two positioning blocks one by one, the positioning blocks are inserted into the corresponding air wheel positioning holes to position the air wheel stator and prevent mistakes, the positioning blocks are in a stepped shape, the PCBA board is placed on the stepped surface of the positioning blocks to ensure that the upper surface of the air wheel has a certain gap with the PCBA board, and collision is prevented.

5. The dual channel air quality sensor of claim 1, wherein, The side surface of the middle cover is provided with an indoor air inlet, an indoor air outlet, an outdoor air inlet and an outdoor air outlet; The inside of the lower cover is provided with a first sealing rib and a second sealing rib, the first sealing rib and the second sealing rib respectively enclose a first closed area and a second closed area, and the first sealing rib and the second sealing rib are closely attached to the bottom surface of the middle cover; The indoor air duct comprises a first air wheel cavity and a first air duct which are isolated from each other, the first air duct is communicated with the outdoor air inlet, the first air wheel cavity is communicated with the outdoor air outlet, the bottom of the first air wheel cavity is provided with a first air inlet, the bottom of the first air duct is provided with a first air outlet, the first air outlet and the first air inlet are communicated with the first closed area in the lower cover; The outdoor air duct comprises a second air wheel cavity and a second air duct which are isolated from each other, the second air duct is communicated with the outdoor air inlet, the second air wheel cavity is communicated with the outdoor air outlet, the bottom of the second air wheel cavity is provided with a second air inlet, the bottom of the second air duct is provided with a second air outlet, the second air outlet and the second air inlet are communicated with the second closed area in the lower cover; The two air wheels are arranged in the first air wheel cavity and the second air wheel cavity respectively. The bottom surface of the middle cover is rubberized at positions corresponding to the first sealing rib and the second sealing rib, and the rubberized part is closely attached to the first sealing rib and the second sealing rib.

6. The dual channel air quality sensor of claim 5, wherein, The side of the middle cover close to the PCBA board is rubberized, the outdoor air duct is located in the rubberized area, and the PCBA board presses the rubberized part on the middle cover.

7. The dual channel air quality sensor of claim 1 or 6, wherein, Two different types of connectors are arranged on the PCBA board, and any one connector can supply power and transmit signals to the PCBA board.

8. The dual channel air quality sensor of claim 1, wherein, The inside of the lower cover is provided with a plurality of screw mounting columns, through holes are arranged on the middle cover and the PCBA board at positions corresponding to the screw mounting columns, and screws are locked on corresponding threaded hole columns in the lower cover after penetrating through the through holes on the middle cover and the PCBA board, so that the middle cover, the lower cover and the PCBA board are connected through the screws.

9. The dual channel air quality sensor of claim 1, wherein, ​ 10. The dual channel air quality sensor of claim 1, wherein, The PCBA board is provided with a plurality of PCBA positioning holes, and the middle cover is internally provided with a plurality of PCBA positioning columns which are inserted into the corresponding PCBA positioning holes.

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