WO2016105555A1 - Systèmes et procédés de comptage de particules en suspension dans l'air portables - Google Patents

Systèmes et procédés de comptage de particules en suspension dans l'air portables Download PDF

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Publication number
WO2016105555A1
WO2016105555A1 PCT/US2015/000432 US2015000432W WO2016105555A1 WO 2016105555 A1 WO2016105555 A1 WO 2016105555A1 US 2015000432 W US2015000432 W US 2015000432W WO 2016105555 A1 WO2016105555 A1 WO 2016105555A1
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WO
WIPO (PCT)
Prior art keywords
light
region
air
sensing region
particles
Prior art date
Application number
PCT/US2015/000432
Other languages
English (en)
Inventor
Eric Paulos
Rundong TIAN
Christie DIERK
Chris Myers
Original Assignee
The Regents Of The University Of California
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Regents Of The University Of California filed Critical The Regents Of The University Of California
Publication of WO2016105555A1 publication Critical patent/WO2016105555A1/fr

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Classifications

    • 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
    • G01N15/10—Investigating individual particles
    • G01N15/14—Optical investigation techniques, e.g. flow cytometry
    • G01N15/1456—Optical investigation techniques, e.g. flow cytometry without spatial resolution of the texture or inner structure of the particle, e.g. processing of pulse signals
    • G01N15/1459—Optical investigation techniques, e.g. flow cytometry without spatial resolution of the texture or inner structure of the particle, e.g. processing of pulse signals the analysis being performed on a sample stream
    • 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
    • G01N15/02—Investigating particle size or size distribution
    • G01N15/0205—Investigating particle size or size distribution by optical means
    • 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
    • G01N15/10—Investigating individual particles
    • G01N15/14—Optical investigation techniques, e.g. flow cytometry
    • G01N2015/1493—Particle size

Definitions

  • Low-cost air quality sensing often consists of some form of gas sensor, typically a thermal conductivity based detector tuned to respond to carbon monoxide, ozone, nitrogen oxides, or other gases.
  • gas sensor typically a thermal conductivity based detector tuned to respond to carbon monoxide, ozone, nitrogen oxides, or other gases.
  • these devices do a poor job of accurately measuring the actual gas concentrations due to sensor response selectivity and gas interaction problems.
  • gas sensors are high-power due to their thermal heating requirements.
  • these gas sensors do not measure the primary air pollutant in regards to human health which is airborne particles.
  • the present disclosure advantageously provides airborne particle counting systems and methods.
  • the device embodiments demonstrate a signal response consistent with highly calibrated particle sensors. Also, because of the smaller, flexible form factor, and low-power usage, a wide variety of embedded applications, data logging, and wireless applications are possibilities for these sensor embodiments.
  • a particle counting device includes a housing structure defining an enclosed flow path and having an air inlet region and an air outlet region, a light source that emits a beam of light, and a photodetector having a sensing region that intersects the beam of light.
  • a housing structure defining an enclosed flow path and having an air inlet region and an air outlet region, a light source that emits a beam of light, and a photodetector having a sensing region that intersects the beam of light.
  • an air flow received at the inlet region is directed (pushed or pulled) towards the outlet region through the sensing region, wherein particles in the air flow scatter the beam of light when in the sensing region, and wherein the photodetector detects scattered light and produces a detection signal representative of airborne particles detected, such as sizes and counts.
  • the light source includes a laser.
  • the housing structure is configured with at least one bend or turn between the inlet region and the sensing region to direct the air flow from the inlet region.
  • the device further includes a fan that pulls air from the inlet region to the outlet region.
  • the detection signal represents numbers and sizes of particles detected in the air flow.
  • the device further includes a communication module adapted to provide the detection signal to an external device.
  • the communication module implements a wireless protocol for communicating with the external device.
  • the wireless protocol is a Bluetooth protocol.
  • the device further includes a straightener module positioned proximal the inlet region, wherein the straightener module reduces an amount of ambient light entering the flow path.
  • the device further includes a light trap structure or region that traps light from the light source after impinging on the sensing region
  • Figure 1 shows an air particle counter device according to an embodiment.
  • Figure 2a shows a piece-wise perspective view of the device of Figure 1.
  • Figure 2b shows top, bottom and perspective views of the device of Figure 1.
  • Figure 3 shows a still frame of a smoke test video of the device of Figure 1.
  • Figure 4 shows results of a series of side by side tests conducted with a calibrated etOne HPPC-6 particle sensor across fifteen locations such as indoor offices, restaurants, subways, and bus stations.
  • Figure 5 shows examples of user interfaces on a smart phone device according to an embodiment.
  • the present disclosure relates generally to airborne particle detection and counting systems and methods.
  • Figure 1 shows an air particle counter device 10 according to an embodiment.
  • Device 10 includes a light source 5, such as a laser source, and a light detector or
  • the photodetector 6 such as a photodiode, arranged orthogonally such that the focal point of the laser is located in a sensing region of detector 6, e.g., proximal light detector 6.
  • the light source 5 may include a laser and detector 6 may include a photodiode, wherein the laser and photodiode are arranged orthogonally such that the focal point of the laser 5 is located directly above the photodiode 6 as shown in Figure 1.
  • Air is drawn through the system from inlet region 9 across the detection region of photodiode 6 using a small fan positioned or located within the device so as to create a negative pressure at inlet region 9 and draw air with any particulate matter into the inner portion of device 10.
  • FIG. 2a shows a piece-wise perspective view of device 10 and Figure 2b shows top, bottom and perspective views of device 10.
  • the light source 5 may include a diode laser, or other laser. Alternatively, a coherent light source other than a laser may be used, or a LED or other source may be used. Also, detector 6 may include any optical detector or any device that converts an optical signal into an electrical signal may be used. Examples of useful detectors might include PIN photodiodes and avalanche photodiodes.
  • these design features include one or more of the following: (1) a specially shaped air passage which minimizes the amount of ambient light that reaches the detection or sensing region, while still allowing for laminar flow across the sensing region of the photodiode, (2) the use of a centrifugal fan for additional ambient light rejection at the flow outlet, and (3) the selection of materials which have high absorption rates for the visible wavelengths of light. Examples of such materials might include materials having matted finishes or selective coatings (e.g., black paint).
  • the flow of air over the detector 6 should be non-turbulent and of a constant rate to allow for accurate calculation of particle density.
  • a large percentage of ambient light should be shielded from the detector 6 such that changing light conditions will not affect the calibration of the sensor device.
  • No existing sensor device has addressed both of these issues simultaneously.
  • existing devices typically should not be operated in direct sunlight or other bright light source as this could affect count accuracy in such devices. This is a significant limitation for air particle sensors or monitors if they are to be portable and functional across a wide range of environments where people go, including outdoors.
  • the air channels leading to and from the detector 6 include one or multiple turns to prevent ambient light from illuminating the photodiode.
  • Figure 1 shows an embodiment with a single turn 12 in the air channel.
  • a flow straightener 8 at the inlet 9 and a centrifugal fan 7 at the outlet (not shown) may be used to further prevent light from entering the system or reduce the amount of light entering the system.
  • Simple calculations of the Reynold's number were performed to guide the design of the flow channel to ensure non-turbulent flow. Because of the complex channel geometry, qualitative smoke tests (Figure 3) were conducted to confirm the absence of turbulence and other detrimental effects, such as eddies which may recirculate particles and decrease the responsiveness and accuracy of the sensor.
  • a light trap region 13 is provided to prevent source light and/or stray reflected light from returning to the sensing region.
  • the light trap region 13 may include a light absorptive material (e.g., coating) and have a configuration that results in multiple reflections, and hence multiple absorptions, to thereby reduce or eliminate any light entering the light trap region from exiting the light trap region.
  • an optional light baffle module 4 is included to contain the source light and further prevent unwanted light from traversing the interior of the device.
  • the light baffle 4 may include a series of one or more plates with pinholes arranged along the direction of the source beam.
  • an integrated photodiode and amplifier (OPT101) is used to simplify the electronics design of the system.
  • the output of the OPT101 can be further amplified and attenuated in multiple, e.g., three, stages using a low power operational amplifier.
  • the analog signal is sampled by a processor, e.g., an ARM Cortex M4 based processor at 12 bits at 200 kHz.
  • a mostly interrupt driven system calculates when particles of two different size ranges have been detected during a time window, and stores a buffer of counts during previous time windows.
  • the data can be logged on the device and/or transmitted wirelessly, e.g., using Bluetooth Low Energy (BLE) to a nearby device.
  • BLE Bluetooth Low Energy
  • a small form-factor battery such as a small 400m Ah LiPo battery, may be used which allows for taking multiple, e.g., 120, distinct readings, or 8 hours of data when sampled every 6 minutes.
  • the sampling parameters can of course be adjusted or varied to suit particular applications or power requirements.
  • the devices according to the present embodiments can be used for sensing air quality. Because they are generally of low cost and size they can be used to allow a user to capture, log, and view their daily exposure.
  • a networked device such as a mobile phone embodiments can allow for crowd sourced applications of citizen data collection of health issues around air particles or pollen counts throughout indoor and outdoor locations.
  • Such devices can also be embedded into a watch form factor or attached to a skateboard, bike, car, etc.
  • Such devices can also be used to determine location such as indoor or outdoor and can be used to help other communities or agencies marshal resources by helping inform where higher concentrations of air pollutants are located.
  • Such devices can help build maps of clean routes for jogging, the least polluted parks to visit, the healthiest path to bike through a city, etc. Use of such devices also raises general awareness about air quality and
  • While the present embodiments can operate standalone and log data, their usage may be more persuasive and compelling when the data is experienced real-time through a user interface, e.g., through a mobile phone interface.
  • a user interface e.g., through a mobile phone interface.
  • BLE Bluetooth Low Energy
  • live particle count data can be transmitted to a handheld device such as an Apple iPhone running an iOS App (Figure 5).
  • the interface supports scaffolding a user into the data— from a compelling real-time visualization that invites curiosity into a deeper exploration of the rich particle dataset with time and location patterns.
  • a user interface is composed of three screens: (1 ) an animated, ambient display that allows users to easily visualize the air quality, (2) a bar graph view that communicates precise particle counts and corresponding health related information, and (3) an interactive stacked graph view that displays historical readings across time and location.
  • the initial screen of the application may display animated particles as colorful circles that move and interact as a particle simulation system on the screen.
  • the two sizes of particles e.g., small and large
  • the two sizes of particles are distinguished by their color (e.g., blue/purple), size, and movement (e.g., fast/slow).
  • Updates to this screen are deliberate, with particles slowly fading in and out such that the user is made aware of changing air quality conditions.
  • This screen is unique in that it is factual, yet playfully aesthetic.
  • the user may swipe in one direction, e.g., left, to access the bar graph view.
  • the individual particles are stacked and viewed as a whole.
  • the precise number of each particle size is displayed along with more information, such as the precise size of the particles, common origins of such particles, and health concerns associated with the current air quality conditions.
  • the user can access a final display, such as a stacked line graph, e.g., by rotating their phone into landscape position or otherwise selecting a display option.
  • This graph displays all past readings of the device.
  • a stacked line graph is advantageous as it allows the user to see readings for both sizes of particles, as well as total number of particles.
  • This view is interactive, allowing the user to zoom in/out, scroll forwards and backwards, and learn more about any particular reading; tapping on a specific data point displays the location, date, and precise number of particles for that reading.
  • An advantage of the present embodiments is the ability to easily be adapted into a variety of form factors and lifestyle application settings. A subset of such exemplary design possibilities include the following:
  • Carabiner / Clip On With the addition of an exterior loop and minor changes in the exterior geometry, this application can be easily implemented enabling air quality measurements from book-bags, purses, etc.
  • Bike and Stroller In this example the device may take on the familiar water bottle like form factor enabling easy integration into biking and stroller activities.
  • Watch The size constraints of the watch form factor are governed in part by the size of the laser. Though proper part selections, one can readily adapt the device to a worn device.
  • the device may be integrated into a toy, e.g., into a toy airplane.
  • the large fuselage affords easy integration of the sensor and enables a new culture of participation into sensing by children.

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  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

L'invention concerne des dispositifs et des procédés de comptage de particules. Un dispositif de comptage de particules comprend une structure de boîtier définissant un trajet d'écoulement fermé et comportant une zone d'admission d'air et une zone de sortie d'air, une source de lumière qui émet un faisceau de lumière, et un photodétecteur comportant une région de détection qui coupe le faisceau de lumière. En fonctionnement, un flux d'air reçu au niveau de la zone d'entrée est dirigé (poussé ou tiré) vers la zone de sortie à travers la région de détection, des particules dans l'écoulement d'air diffusant le faisceau de lumière lorsqu'il se trouve dans la région de détection et le photodétecteur détectant la lumière diffusée et produisant un signal de détection représentatif des particules en suspension dans l'air détectées, tel que leur taille et leur nombre.
PCT/US2015/000432 2014-12-23 2015-12-28 Systèmes et procédés de comptage de particules en suspension dans l'air portables WO2016105555A1 (fr)

Applications Claiming Priority (2)

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US201462096371P 2014-12-23 2014-12-23
US62/096,371 2014-12-23

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WO2016105555A1 true WO2016105555A1 (fr) 2016-06-30

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107179267A (zh) * 2017-07-03 2017-09-19 博耐尔汽车电气系统有限公司 一种激光pm2.5传感器封装装置及汽车
CN107255609A (zh) * 2017-07-03 2017-10-17 博耐尔汽车电气系统有限公司 激光pm2.5传感器封装装置及汽车
CN107340210A (zh) * 2017-07-03 2017-11-10 博耐尔汽车电气系统有限公司 一种封装装置及汽车
CN108645771A (zh) * 2018-08-11 2018-10-12 浙江舜业净化科技有限公司 一种检测大气颗粒物浓度的装置及其方法
WO2019034949A1 (fr) * 2017-08-18 2019-02-21 山东诺方电子科技有限公司 Dispositif de surveillance des polluants atmosphériques
WO2020038593A1 (fr) * 2018-08-21 2020-02-27 Ams Ag Capteur de matière particulaire
CN110873686A (zh) * 2018-08-30 2020-03-10 研能科技股份有限公司 微粒检测模块
CN110873679A (zh) * 2018-08-30 2020-03-10 研能科技股份有限公司 微粒检测模块

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WO1990010858A1 (fr) * 1989-03-06 1990-09-20 Tsi Incorporated Detecteur de particules individuelles utilisant des techniques de diffusion de la lumiere
US5085500A (en) * 1989-11-28 1992-02-04 Tsi Incorporated Non-imaging laser particle counter
US20060263925A1 (en) * 2005-05-10 2006-11-23 Chandler David L Ethernet-powered particle counting system

Patent Citations (4)

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US3770351A (en) * 1971-11-23 1973-11-06 Science Spectrum Optical analyzer for microparticles
WO1990010858A1 (fr) * 1989-03-06 1990-09-20 Tsi Incorporated Detecteur de particules individuelles utilisant des techniques de diffusion de la lumiere
US5085500A (en) * 1989-11-28 1992-02-04 Tsi Incorporated Non-imaging laser particle counter
US20060263925A1 (en) * 2005-05-10 2006-11-23 Chandler David L Ethernet-powered particle counting system

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107179267B (zh) * 2017-07-03 2020-03-20 博耐尔汽车电气系统有限公司 一种激光pm2.5传感器封装装置及汽车
CN107255609A (zh) * 2017-07-03 2017-10-17 博耐尔汽车电气系统有限公司 激光pm2.5传感器封装装置及汽车
CN107340210A (zh) * 2017-07-03 2017-11-10 博耐尔汽车电气系统有限公司 一种封装装置及汽车
CN107255609B (zh) * 2017-07-03 2019-11-26 博耐尔汽车电气系统有限公司 激光pm2.5传感器封装装置及汽车
CN107340210B (zh) * 2017-07-03 2019-11-26 博耐尔汽车电气系统有限公司 一种封装装置及汽车
CN107179267A (zh) * 2017-07-03 2017-09-19 博耐尔汽车电气系统有限公司 一种激光pm2.5传感器封装装置及汽车
WO2019034949A1 (fr) * 2017-08-18 2019-02-21 山东诺方电子科技有限公司 Dispositif de surveillance des polluants atmosphériques
WO2019210720A1 (fr) * 2017-08-18 2019-11-07 山东诺方电子科技有限公司 Dispositif de surveillance de polluants atmosphériques résistant aux interférences du vent
CN108645771A (zh) * 2018-08-11 2018-10-12 浙江舜业净化科技有限公司 一种检测大气颗粒物浓度的装置及其方法
WO2020038593A1 (fr) * 2018-08-21 2020-02-27 Ams Ag Capteur de matière particulaire
CN112585447A (zh) * 2018-08-21 2021-03-30 ams有限公司 颗粒物传感器
US11885726B2 (en) 2018-08-21 2024-01-30 Ams Ag Particulate matter sensor
CN112585447B (zh) * 2018-08-21 2024-06-28 ams有限公司 颗粒物传感器
CN110873679A (zh) * 2018-08-30 2020-03-10 研能科技股份有限公司 微粒检测模块
CN110873686A (zh) * 2018-08-30 2020-03-10 研能科技股份有限公司 微粒检测模块
CN110873686B (zh) * 2018-08-30 2023-02-03 研能科技股份有限公司 微粒检测模块
CN110873679B (zh) * 2018-08-30 2023-02-21 研能科技股份有限公司 微粒检测模块

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