CN115493982A - Single-laser double-channel dust sensor - Google Patents
Single-laser double-channel dust sensor Download PDFInfo
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- CN115493982A CN115493982A CN202211122136.0A CN202211122136A CN115493982A CN 115493982 A CN115493982 A CN 115493982A CN 202211122136 A CN202211122136 A CN 202211122136A CN 115493982 A CN115493982 A CN 115493982A
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- laser
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- dust sensor
- beam splitter
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- 239000000428 dust Substances 0.000 title claims abstract description 31
- 238000001514 detection method Methods 0.000 claims abstract description 34
- 230000005540 biological transmission Effects 0.000 claims abstract description 31
- 230000010287 polarization Effects 0.000 claims abstract description 28
- 230000003287 optical effect Effects 0.000 claims description 22
- 230000009977 dual effect Effects 0.000 claims description 11
- 230000008033 biological extinction Effects 0.000 abstract description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000003915 air pollution Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 238000005538 encapsulation Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/06—Investigating concentration of particle suspensions
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
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- G01N15/075—
Abstract
The invention discloses a single-laser double-channel dust sensor which comprises a shell, a laser module, two PD photosensitive diodes, a polarization beam splitter and two air flow driving devices, wherein the shell is provided with a plurality of laser light sources; two groups of air ducts, two light traps, two PD through holes and a laser emission chamber are formed on the shell; the laser module and the polarization beam splitter are arranged in the laser emission chamber, and the polarization beam splitter divides laser emitted by the laser module into transmission laser and reflection laser, the transmission laser and the reflection laser are emitted from a transmission window and a reflection window of the laser emission chamber respectively and enter the two air channels respectively; reflected light and scattered light generated by laser irradiation on dust of the gas to be detected enter the PD photosensitive diode positioned below the PD through hole, and redundant laser directly enters the light trap for extinction. This dust sensor adopts a laser module to support dust detection such as binary channels PM2.5 or PM10, can reduce product cost effectively, and saves product space, and the finished product volume of assembling is also less.
Description
Technical Field
The invention relates to the field of environment detection sensors, in particular to a single-laser double-channel dust sensor.
Background
The dust sensor detects dust particles in the air by using a laser scattering principle.
Along with the improvement of living standard of people, the automobile is provided with a double-channel PM2.5 sensor to measure the concentration of dust particles inside and outside the automobile, and the air conditioner is combined to realize air filtration or switch an internal and external circulation mode of the air conditioner, so that air pollution inside the automobile is avoided, and the air freshness of the driving environment is ensured. But the present two channel sensor all adopts two laser module to measure, and the laser module is regarded as PM2.5 sensor core component, and technical requirement is higher and occupy very big cost, and the finished product volume of assembling is also great.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a single-laser dual-channel dust sensor to reduce the cost and the volume of the finished product.
In order to achieve the purpose, the invention provides a single-laser double-channel dust sensor which comprises a shell, a laser module, two PD photosensitive diodes, a polarization beam splitter and two air flow driving devices, wherein the shell is provided with a plurality of laser channels;
forming a first air duct, a second air duct, a first light trap, a second light trap, a first PD through hole, a second PD through hole and a laser emission chamber in the shell;
the laser module and the polarization beam splitter are arranged in the laser emission chamber, the laser emission chamber is provided with a transmission window and a reflection window, the polarization beam splitter is used for dividing laser emitted by the laser module into transmission laser and reflection laser, and the transmission laser is emitted from the transmission window and enters the first air channel; the reflected laser is emitted from the reflecting window and enters the second air duct;
the first air duct comprises a first air inlet, a first detection section and a first air outlet which are connected in sequence; the first detection section is communicated with the first optical trap, the first PD through hole and the transmission window, an incident port of the first optical trap is opposite to the transmission window, and the first PD through hole is vertical to the transmission window; a first PD photodiode is arranged below the first PD through hole;
the second air duct comprises a second air inlet, a second detection section and a second air outlet which are connected in sequence; the second detection section is communicated with the second optical trap, the second PD through hole and a reflection window of the laser emission chamber, an incident port of the second optical trap is opposite to the reflection window, and the second PD through hole is vertical to the reflection window; a second PD photodiode is arranged below the second PD through hole;
the two airflow driving devices are respectively arranged in the first air duct and the second air duct.
Furthermore, the laser module comprises a laser diode and a focusing lens, and the focal point of transmission laser formed by a light beam emitted by the laser diode after passing through the focusing lens and the polarization beam splitter is positioned in the first detection section; the light beam emitted by the laser diode passes through the focusing lens and the polarization beam splitter to form a reflected laser focus which is positioned in the second detection section.
Further, the focal point of the transmitted laser is located in the region above the hole center of the first PD through hole; and the reflection focus of the laser emitted by the laser module is positioned in the area above the hole center of the second PD through hole.
Furthermore, for conveniently setting a light path, the polarization beam splitter and the laser module emit laser light with an included angle of 45 degrees.
Further, the transflective splitting ratio of the polarization splitting sheet is 1: 9. 2: 8. 3: 7. 4: 6. 5: 5. 6: 4. 7: 3. 8: 2. 9:1.
furthermore, in order to prevent air leakage between air ducts, the joint of the polarization beam splitter and the laser emission chamber is sealed, and the laser emission chamber is divided into two chambers.
Further, the first detection section is the narrowest part of the first air duct; the second detection section is the narrowest part of the second air duct.
Furthermore, the casing is an approximately square structure, the first air duct and the second air duct are approximately symmetrically distributed, and the first air inlet, the first air outlet, the second air outlet and the second air inlet are sequentially distributed on four side faces of the casing.
Furthermore, two airflow driving devices are respectively arranged at the first air outlet and the second air outlet.
Further, the airflow driving device is a fan or a pump.
The invention realizes the following technical effects:
the utility model provides a dust sensor adopts a laser module to support dust detection such as binary channels PM2.5 or PM10, can reduce product cost effectively, and saves product space, and the finished product volume of assembling is also less.
Drawings
FIG. 1 is a cross-sectional view of a single laser dual channel dust sensor in accordance with a preferred embodiment of the present invention;
FIG. 2 is a schematic laser path of the single laser dual channel dust sensor of the present invention.
Reference numerals:
10-a laser module; 20-a housing; 21-a first air duct; 22-an optical trap; 23-a first PD via;
24-a second air duct; 25-light trap; 26-a second PD via; 27-a laser emission chamber;
30-polarization beam splitter; 41. 42 an air flow driving device;
101-a laser diode; 102-a focusing lens; 103-laser housing;
211-a first inlet; 212-first detection segment; 213-first outlet port;
221-entrance port; 222-an incident bevel; 223-a diffusive reflective surface;
241-a second air inlet; 242 — a second detection segment; 243-a second air outlet;
271-a transmission window; 272-reflective window.
Detailed Description
To further illustrate the various embodiments, the present invention provides the accompanying figures. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references, one of ordinary skill in the art will appreciate other possible embodiments and advantages of the present invention. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.
The invention will now be further described with reference to the accompanying drawings and detailed description.
As shown in fig. 1, the present application presents a cross-sectional schematic view of a PM2.5 sensor. The PM2.5 sensor includes a housing 20, a laser module 10, two PD photodiodes (not shown), a polarization splitter 30, and two airflow drivers 41, 42.
The housing 20 has a first air duct 21, a second air duct 24, a first light trap 22, a second light trap 25, a laser emission chamber 27, and a first PD via 23 and a second PD via 26.
The laser module 10 and the polarization beam splitter 30 are disposed in the laser emission chamber 27, the laser emission chamber 27 is provided with a transmission window 271 and a reflection window 272, and the polarization beam splitter 30 divides the laser light S1 emitted from the laser module 10 into transmission laser light S2 and reflection laser light S3, and emits the transmission laser light S2 and the reflection laser light S3 from the transmission window 271 and the reflection window 272, respectively.
The first air duct 21 includes a first air inlet 211, a first detection section 212, and a first air outlet 213, which are connected in sequence; the side wall of the first detection section 212 is communicated with the first optical trap 22, the first PD through hole 23 and the transmission window 271 of the laser emission chamber 27, the incident port of the first optical trap 22 is opposite to the transmission window 271, and the first PD through hole 23 is perpendicular to the transmission window 271; a PD photodiode is arranged below the first PD via 23. After the transmission laser exits the transmission window 271, the transmission laser irradiates the dust of the gas to be detected in the first detection section 212, the generated reflected and scattered light enters the first PD through hole 23, is received and detected by the PD photodiode, and the remaining laser directly enters the first optical trap 22 and is extinguished in the first optical trap 22.
The second air duct 24 includes a second air inlet 241, a second detection section 242 and a second air outlet 243 which are connected in sequence; the side wall of the second detection section 242 communicates with the second optical trap 25, the second PD via hole 26, and the reflection window 272 of the laser emission chamber 27, the entrance port of the second optical trap 25 is opposite to the reflection window 272, and the second PD via hole 26 is perpendicular to the reflection window 272; a PD photodiode is arranged below the second PD via 26. After the reflected laser light exits the reflection window 272, the reflected laser light irradiates the dust of the gas to be detected in the second detection section 242, and the generated reflected and scattered light enters the second PD through hole 26 and is received and detected by the PD photodiode; the remaining laser light is directed into the second optical trap 25 and is extinguished in the second optical trap 25.
In this embodiment, the laser module 10 includes a laser diode 101, a focusing lens 102 and a laser housing 103, wherein a light beam emitted by the laser diode 101 passes through the focusing lens 102 and the polarization beam splitter 30 to form a focal point P1 of transmitted laser, and the focal point P1 is located in the first detection section 212; the light beam emitted from the laser diode 101 passes through the focusing lens 102 and the polarization beam splitter 30 to form a reflected laser having a focal point P2 located in the second detection section 242. By focusing, the laser energy of the detection area can be maximized, the measurement accuracy can be improved, and the service life of the laser diode 101 can be prolonged.
Preferably, the transmission focus P1 of the laser emitted by the laser module 10 is located in the region above the hole center of the first PD through hole 23; the reflection focal point P2 of the laser emitted from the laser module 10 is located in the region above the hole center of the second PD via 26.
Preferably, for convenience of installation, the polarization beam splitter 30 and the optical axis of the laser emitted from the laser module 10 form an angle of 45 °, so that the angle between the transmission window 271 and the reflection window 272 is 90 °. The design also facilitates the rational utilization of the housing space.
In this embodiment, the transmittance and reflectance of the polarization splitter 30 can be further adjusted by coating according to the required optical power ratio of the two channels. Preferably, the transflective splitting ratio of the conventional polarization splitter 30 is 1: 9. 2: 8. 3: 7. 4: 6. 5: 5. 6: 4. 7: 3. 8: 2. 9:1, etc.
In this embodiment, blow-by is generated by the laser emitting chamber 27 in order to prevent the air to be measured in the two air paths from passing through. The joint of the polarization beam splitter 30 and the laser emission chamber 27 is sealed, and the laser emission chamber 27 is divided into two chambers.
In the present embodiment, the first detecting section 212 is the narrowest part of the first air duct 21; the second sensing section 242 is the narrowest portion of the second air chute 24. Therefore, the flow speed of the gas to be detected in the detection section is fastest, and dust in the gas to be detected cannot be accumulated in the air channel so as to avoid influencing subsequent detection.
The optical traps 22 and 25 are used for reflecting redundant laser light passing through the detection section for multiple times, so that extinction is realized, and light is prevented from returning to the detection section to influence measurement accuracy. In the present embodiment, the optical trap 22 includes an incident port 221, an incident slope 222, and a diffusive reflective surface 223. The excessive laser light is incident into the optical trap 22 from the incident port 221, is emitted to the diffuse reflection surface 223 through the incident inclined surface 222, and is reflected on the diffuse reflection surface 223 multiple times to achieve an extinction effect.
In this embodiment, the housing 20 is approximately square, the first air duct 21 and the second air duct 24 are approximately symmetrically distributed, and the first air inlet 211, the first air outlet 213, the second air outlet 243, and the second air inlet 241 are sequentially distributed on four side surfaces of the housing 20. In specific implementation, the cavities such as the air duct, the laser emitting chamber, and the light trap are all formed on the housing 20. Then, the first air duct 21 and the second air duct 24 are formed independently by sealing the walls of the passages by a secondary encapsulation process. The mode is convenient to process and assemble, can ensure that the product has compact structure and smaller volume, and is convenient to connect an external pipeline.
In this embodiment, the first air outlet 213 and the second air outlet 243 are respectively provided with the air flow driving devices 41 and 42, and the air flow driving devices 41 and 42 drive the circulation of air in the air duct, so as to realize the quick update of the air sample, thereby ensuring the timeliness and effectiveness of the PM2.5 measurement. In particular, the airflow driving device may be a fan or a pump.
The utility model provides a dust sensor adopts a laser module to support the dust detection of binary channels's PM2.5 or PM10 isotatic, can reduce product cost effectively, and saves the product space, and the finished product volume of assembling is also less.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A single-laser double-channel dust sensor is characterized by comprising a shell, a laser module, two PD photosensitive diodes, a polarization beam splitter and two air flow driving devices;
forming a first air duct, a second air duct, a first light trap, a second light trap, a first PD through hole, a second PD through hole and a laser emission chamber in the shell;
the laser module and the polarization beam splitter are arranged in the laser emission chamber, the laser emission chamber is provided with a transmission window and a reflection window, the polarization beam splitter is used for dividing laser emitted by the laser module into transmission laser and reflection laser, and the transmission laser is emitted from the transmission window and enters the first air channel; the reflected laser is emitted from the reflecting window and enters the second air duct;
the first air duct comprises a first air inlet, a first detection section and a first air outlet which are connected in sequence; the first detection section is communicated with the first optical trap, the first PD through hole and the transmission window, an incident port of the first optical trap is opposite to the transmission window, and the first PD through hole is vertical to the transmission window; a first PD photodiode is arranged below the first PD through hole;
the second air duct comprises a second air inlet, a second detection section and a second air outlet which are connected in sequence; the second detection section is communicated with the second optical trap, the second PD through hole and a reflection window of the laser emission chamber, an incident port of the second optical trap is opposite to the reflection window, and the second PD through hole is vertical to the reflection window; a second PD photodiode is arranged below the second PD through hole;
the two airflow driving devices are respectively arranged in the first air duct and the second air duct.
2. The single laser dual channel dust sensor as claimed in claim 1, wherein the laser module comprises a laser diode and a focusing lens, and the focal point of the transmitted laser formed by the light beam emitted from the laser diode passing through the focusing lens and the polarization beam splitter is located in the first detection section; and the focal point of the reflected laser formed by the light beam emitted by the laser diode after passing through the focusing lens and the polarization beam splitter is positioned in the second detection section.
3. The single laser dual channel dust sensor of claim 1, wherein the focal point of the transmitted laser light is located in a region above the hole center of the first PD via; and the reflection focus of the laser emitted by the laser module is positioned in the area above the hole center of the second PD through hole.
4. The single laser dual channel dust sensor of claim 1, wherein the polarization beam splitter and the laser module exit laser beam have an angle of 45 °.
5. The single laser dual channel dust sensor of claim 1, wherein the polarization beam splitter has a transflective splitting ratio of 1: 9. 2: 8. 3: 7. 4: 6. 5: 5. 6: 4. 7: 3. 8: 2. 9:1.
6. the single laser dual channel dust sensor of claim 1, wherein the joint of the polarization splitter and the laser emission chamber is sealed to separate the laser emission chamber into two chambers.
7. The single laser dual channel dust sensor of claim 1, wherein the first sensing segment is the narrowest point of the first wind tunnel; the second detection section is the narrowest part of the second air duct.
8. The single laser dual channel dust sensor of claim 1, wherein the housing is approximately square, the first air channel and the second air channel are approximately symmetrically distributed, and the first air inlet, the first air outlet, the second air outlet and the second air inlet are sequentially distributed on four sides of the housing.
9. The single laser dual channel dust sensor of claim 1, wherein two gas flow drivers are mounted at said first gas outlet and said second gas outlet, respectively.
10. The single laser dual channel dust sensor of claim 1, wherein the airflow driving device is a fan or a pump.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211122136.0A CN115493982A (en) | 2022-09-15 | 2022-09-15 | Single-laser double-channel dust sensor |
| PCT/CN2022/124798 WO2024055377A1 (en) | 2022-09-15 | 2022-10-12 | Single-laser dual-channel dust sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211122136.0A CN115493982A (en) | 2022-09-15 | 2022-09-15 | Single-laser double-channel dust sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115493982A true CN115493982A (en) | 2022-12-20 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211122136.0A Pending CN115493982A (en) | 2022-09-15 | 2022-09-15 | Single-laser double-channel dust sensor |
Country Status (2)
| Country | Link |
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| CN (1) | CN115493982A (en) |
| WO (1) | WO2024055377A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116858741A (en) * | 2023-09-04 | 2023-10-10 | 天津华泰清源环境技术有限公司 | Raise dust on-line monitoring system |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101819128B (en) * | 2010-04-26 | 2011-11-16 | 浙江万里学院 | Laser dust detection device for resisting dust deposition disturbance |
| CN204831979U (en) * | 2015-08-28 | 2015-12-02 | 中煤科工集团重庆研究院有限公司 | Binary channels atmosphere raise dust on -line monitoring equipment |
| CN207832626U (en) * | 2018-03-05 | 2018-09-07 | 厦门美时美克空气净化有限公司 | A kind of binary channels detection of air quality module |
| CN108956402B (en) * | 2018-08-07 | 2020-08-11 | 东南大学 | High-sensitivity dust concentration detection method with composite multi-photosensitive-area structure |
| US11841311B2 (en) * | 2018-11-19 | 2023-12-12 | Samsung Electronics Co., Ltd. | Multimodal dust sensor |
| CN110895235A (en) * | 2019-12-20 | 2020-03-20 | 美时美克(上海)汽车电子有限公司 | Binary channels air quality detection module |
| CN215812278U (en) * | 2021-08-31 | 2022-02-11 | 青岛明华电子仪器有限公司 | Particulate matter measuring device with automatic calibration module |
| CN114460046A (en) * | 2022-01-27 | 2022-05-10 | 苏州奥特福环境科技有限公司 | On-line extraction type wet particulate matter back scattering detection optical system |
| CN218823791U (en) * | 2022-09-15 | 2023-04-07 | 厦门美时美克空气净化有限公司 | Single-laser double-channel dust sensor |
-
2022
- 2022-09-15 CN CN202211122136.0A patent/CN115493982A/en active Pending
- 2022-10-12 WO PCT/CN2022/124798 patent/WO2024055377A1/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116858741A (en) * | 2023-09-04 | 2023-10-10 | 天津华泰清源环境技术有限公司 | Raise dust on-line monitoring system |
| CN116858741B (en) * | 2023-09-04 | 2023-12-12 | 天津华泰清源环境技术有限公司 | Raise dust on-line monitoring system |
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| Publication number | Publication date |
|---|---|
| WO2024055377A1 (en) | 2024-03-21 |
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