Articles | Volume 14, issue 11
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Evaluation methods for low-cost particulate matter sensors
Jeffrey K. Bean
Phillips 66, Bartlesville, OK 74003, United States
Related subject area
Subject: Aerosols | Technique: In Situ Measurement | Topic: Instruments and PlatformsSource apportionment of black carbon and combustion-related CO2 for the determination of source-specific emission factorsCAMP: an instrumented platform for balloon-borne aerosol particle studies in the lower atmosphereNew method to determine black carbon mass size distributionThe realization of autonomous, aircraft-based, real-time aerosol mass spectrometry in the upper troposphere and lower stratosphereA study on the performance of low-cost sensors for source apportionment at an urban background siteA dual-wavelength photothermal aerosol absorption monitor: design, calibration and performanceA high-transmission axial ion mobility classifier for mass–mobility measurements of atmospheric ionsDesign, characterization, and first field deployment of a novel aircraft-based aerosol mass spectrometer combining the laser ablation and flash vaporization techniquesAn instrument for direct measurement of emissions: cooling tower exampleThe Aerosol Research Observation Station (AEROS)Laser imaging nephelometer for aircraft deploymentA new method to quantify particulate sodium and potassium salts (nitrate, chloride, and sulfate) by thermal desorption aerosol mass spectrometryEvaluating the PurpleAir monitor as an aerosol light scattering instrumentUndersizing of aged African biomass burning aerosol by an ultra-high-sensitivity aerosol spectrometerSimulation-aided characterization of a versatile water-based condensation particle counter for atmospheric airborne researchDevelopment of an in situ dual-channel thermal desorption gas chromatography instrument for consistent quantification of volatile, intermediate-volatility and semivolatile organic compoundsAssessment of online water-soluble brown carbon measuring systems for aircraft samplingCharacterizing the performance of a POPS miniaturized optical particle counter when operated on a quadcopter droneA low-cost monitor for simultaneous measurement of fine particulate matter and aerosol optical depth – Part 3: Automation and design improvementsRapid measurement of RH-dependent aerosol hygroscopic growth using a humidity-controlled fast integrated mobility spectrometer (HFIMS)Detection of ship plumes from residual fuel operation in emission control areas using single-particle mass spectrometryHighly time-resolved characterization of carbonaceous aerosols using a two-wavelength Sunset thermal–optical carbon analyzerCaptive Aerosol Growth and Evolution (CAGE) chamber system to investigate particle growth due to secondary aerosol formationDesign and characterization of a new oxidation flow reactor for laboratory and long-term ambient studiesA reel-down instrument system for profile measurements of water vapor, temperature, clouds, and aerosol beneath constant-altitude scientific balloonsAirborne extractive electrospray mass spectrometry measurements of the chemical composition of organic aerosolA semicontinuous study on the ecotoxicity of atmospheric particles using a versatile aerosol concentration enrichment system (VACES): development and field characterizationA novel rocket-borne ion mass spectrometer with large mass range: instrument description and first-flight resultsDetailed characterization of the CAPS single-scattering albedo monitor (CAPS PMssa) as a field-deployable instrument for measuring aerosol light absorption with the extinction-minus-scattering methodNew in situ aerosol hyperspectral optical measurements over 300–700 nm – Part 1: Spectral Aerosol Extinction (SpEx) instrument field validation during the KORUS-OC cruiseNew in situ aerosol hyperspectral optical measurements over 300–700 nm – Part 2: Extinction, total absorption, water- and methanol-soluble absorption observed during the KORUS-OC cruiseContinuous online monitoring of ice-nucleating particles: development of the automated Horizontal Ice Nucleation Chamber (HINC-Auto)Evaluation of optical particulate matter sensors under realistic conditions of strong and mild urban pollutionOptimizing the detection, ablation, and ion extraction efficiency of a single-particle laser ablation mass spectrometer for application in environments with low aerosol particle concentrationsMeasurements of PM2.5 with PurpleAir under atmospheric conditionsDevelopment and application of a mass closure PM2.5 composition online monitoring systemImproved chloride quantification in quadrupole aerosol chemical speciation monitors (Q-ACSMs)Application of TXRF in monitoring trace metals in particulate matter and cloud waterA new optical-based technique for real-time measurements of mineral dust concentration in PM10 using a virtual impactorMIMiX: a Multipurpose In situ Microreactor system for X-ray microspectroscopy to mimic atmospheric aerosol processingApplication of an O-ring pinch device as a constant-pressure inlet (CPI) for airborne samplingResolving the size of ice-nucleating particles with a balloon deployable aerosol sampler: the SHARKSimultaneous measurements of the relative-humidity-dependent aerosol light extinction, scattering, absorption, and single-scattering albedo with a humidified cavity-enhanced albedometerFlow-induced errors in airborne in situ measurements of aerosols and cloudsDevelopment of a new nanoparticle sizer equipped with a 12-channel multi-port differential mobility analyzer and multi-condensation particle countersReal-time pollen monitoring using digital holographyEffect of aerosol composition on the performance of low-cost optical particle counter correction factorsIncrease of the particle hit rate in a laser single-particle mass spectrometer by pulse delayed extraction technologyAerosol measurement methods to quantify spore emissions from fungi and cryptogamic covers in the AmazonThe Universal Cloud and Aerosol Sounding System (UCASS): a low-cost miniature optical particle counter for use in dropsonde or balloon-borne sounding systems
Balint Alfoldy, Asta Gregorič, Matic Ivančič, Irena Ježek, and Martin Rigler
Atmos. Meas. Tech., 16, 135–152,Short summary
Atmospheric concentrations and source apportionment (SA) of black carbon (BC) and CO2 were determined in an urban environment during a heating season. BC particles were attributed to two major sources: traffic and heating. The BC SA was implemented by an Aethalometer model used for the SA of CO2 supposing that the source-specific CO2 components are correlated with the corresponding BC. Source-specific emission factors were determined as a ratio of corresponding BC and CO2 components.
Christian Pilz, Sebastian Düsing, Birgit Wehner, Thomas Müller, Holger Siebert, Jens Voigtländer, and Michael Lonardi
Atmos. Meas. Tech., 15, 6889–6905,Short summary
Tethered balloon observations are highly valuable for aerosol studies in the lowest part of the atmosphere. This study presents a newly developed platform called CAMP with four aerosol instruments for balloon-borne measurements in the Arctic. Laboratory characterizations and evaluations of the instruments and results of a first field deployment are shown. A case study highlights CAMP's capabilities and the importance of airborne aerosol studies for interpretation of ground-based observations.
Weilun Zhao, Gang Zhao, Ying Li, Song Guo, Nan Ma, Lizi Tang, Zirui Zhang, and Chunsheng Zhao
Atmos. Meas. Tech., 15, 6807–6817,Short summary
A new method to determine black carbon mass size distribution (BCMSD) was proposed using the size-resolved absorption coefficient measured by an aerodynamic aerosol classifier in tandem with an aethalometer. This new method fills the gap in the high-time-resolution measurement of BCMSD ranging from upper submicron particle sizes to larger than 1 µm. This method can be applied to field measurement of BCMSD extensively for better understanding BC aging and better estimating the BC climate effect.
Antonis Dragoneas, Sergej Molleker, Oliver Appel, Andreas Hünig, Thomas Böttger, Markus Hermann, Frank Drewnick, Johannes Schneider, Ralf Weigel, and Stephan Borrmann
Atmos. Meas. Tech., 15, 5719–5742,Short summary
The ERICA is a specially designed aerosol particle mass spectrometer for in situ, real-time chemical composition analysis of aerosols. It can operate completely autonomously, in the absence of an instrument operator. Its design has enabled its operation under harsh conditions, like those experienced in the upper troposphere and lower stratosphere, aboard unpressurized high-altitude research aircraft. The instrument has successfully participated in several aircraft operations around the world.
Dimitrios Bousiotis, David C. S. Beddows, Ajit Singh, Molly Haugen, Sebastián Diez, Pete M. Edwards, Adam Boies, Roy M. Harrison, and Francis D. Pope
Atmos. Meas. Tech., 15, 4047–4061,Short summary
In the last decade, low-cost sensors have revolutionised the field of air quality monitoring. This paper extends the ability of low-cost sensors to not only measure air pollution, but also to understand where the pollution comes from. This "source apportionment" is a critical step in air quality management to allow for the mitigation of air pollution. The techniques developed in this paper have the potential for great impact in both research and industrial applications.
Luka Drinovec, Uroš Jagodič, Luka Pirker, Miha Škarabot, Mario Kurtjak, Kristijan Vidović, Luca Ferrero, Bradley Visser, Jannis Röhrbein, Ernest Weingartner, Daniel M. Kalbermatter, Konstantina Vasilatou, Tobias Bühlmann, Celine Pascale, Thomas Müller, Alfred Wiedensohler, and Griša Močnik
Atmos. Meas. Tech., 15, 3805–3825,Short summary
A new photothermal interferometer (PTAAM-2λ) for artefact-free determination of the aerosol absorption coefficient at two wavelengths is presented. The instrument is calibrated with NO2 and polydisperse nigrosin, resulting in very low uncertainties of the absorption coefficients: 4 % at 532 nm and 6 % at 1064 nm. The instrument’s performance makes the PTAAM-2λ a strong candidate for reference measurements of the aerosol absorption coefficient.
Markus Leiminger, Lukas Fischer, Sophia Brilke, Julian Resch, Paul Martin Winkler, Armin Hansel, and Gerhard Steiner
Atmos. Meas. Tech., 15, 3705–3720,Short summary
We developed an axial ion mobility classifier coupled to an atmospheric-pressure interface time-of-flight (APi-TOF) mass spectrometer to measure size-segregated atmospheric ions. We characterize the performance of the novel instrument with bipolar-electrospray-generated ion mobility standards and compare the results with CFD simulations and a simplified numerical particle-tracking model. Ultimately, we report first mass–mobility measurements of atmospheric ions in Innsbruck, Austria.
Andreas Hünig, Oliver Appel, Antonis Dragoneas, Sergej Molleker, Hans-Christian Clemen, Frank Helleis, Thomas Klimach, Franziska Köllner, Thomas Böttger, Frank Drewnick, Johannes Schneider, and Stephan Borrmann
Atmos. Meas. Tech., 15, 2889–2921,Short summary
We have serially combined the two well-established methods for in situ real-time measurement of fine particle chemical composition, the single-particle laser ablation method and the flash evaporation with electron impact ionization method, into a novel instrument. Here we present the design; instrument characteristics, as derived from laboratory and field measurements; and results from the first field deployment during the 2017 StratoClim aircraft campaign.
Christopher D. Wallis, Mason D. Leandro, Patrick Y. Chuang, and Anthony S. Wexler
Atmos. Meas. Tech., 15, 2547–2556,Short summary
Measuring emissions from stacks requires techniques to address a broad range of conditions and measurement challenges. Here we describe an instrument package held by a crane above a stack to characterize both wet droplet and dried aerosol emissions from cooling tower spray drift in situ. The instrument package characterizes the velocity, size distribution, and concentration of the wet droplet emissions and the mass concentration and elemental composition of the dried PM2.5 and PM10 emissions.
Karin Ardon-Dryer, Mary C. Kelley, Xia Xueting, and Yuval Dryer
Atmos. Meas. Tech., 15, 2345–2360,Short summary
The Aerosol Research Observation Station (AEROS) located in West Texas was designed to continuously measure atmospheric particles, including different particulate matter sizes, total particle number concentration, and size distribution. This article provides a description of AEROS as well as an intercomparison of the different instruments using laboratory and atmospheric particles, showing similar concentration as well to distinguish between various pollution events (natural vs. anthropogenic).
Adam T. Ahern, Frank Erdesz, Nicholas L. Wagner, Charles A. Brock, Ming Lyu, Kyra Slovacek, Richard H. Moore, Elizabeth B. Wiggins, and Daniel M. Murphy
Atmos. Meas. Tech., 15, 1093–1105,Short summary
Particles in the atmosphere play a significant role in climate change by scattering light back into space, reducing the amount of energy available to be absorbed by greenhouse gases. We built a new instrument to measure what direction light is scattered by particles, e.g., wildfire smoke. This is important because, depending on the angle of the sun, some particles scatter light into space (cooling the planet), but some light is also scattered towards the Earth (not cooling the planet).
Yuya Kobayashi and Nobuyuki Takegawa
Atmos. Meas. Tech., 15, 833–844,Short summary
We propose a new method to quantify particulate sodium and potassium salts (nitrate, chloride, and sulfate) by using a refractory aerosol thermal desorption mass spectrometer (rTDMS). The combination of a graphite particle collector and a carbon dioxide laser enables high desorption temperature. Laboratory experiments showed that major ion signals originating from sodium or potassium salts were clearly detected, associated with the increase in the desorption temperature by laser heating.
James R. Ouimette, William C. Malm, Bret A. Schichtel, Patrick J. Sheridan, Elisabeth Andrews, John A. Ogren, and W. Patrick Arnott
Atmos. Meas. Tech., 15, 655–676,Short summary
We show that the low-cost PurpleAir sensor can be characterized as a cell-reciprocal nephelometer. At two very different locations (Mauna Loa Observatory in Hawaii and the Table Mountain rural site in Colorado), the PurpleAir measurements are highly correlated with the submicrometer aerosol scattering coefficient measured by a research-grade integrating nephelometer. These results imply that, with care, PurpleAir data may be used to evaluate climate and air quality models.
Steven G. Howell, Steffen Freitag, Amie Dobracki, Nikolai Smirnow, and Arthur J. Sedlacek III
Atmos. Meas. Tech., 14, 7381–7404,Short summary
Small particles in the air have important effects on visibility, clouds, and human health. For the ORACLES project we got a new particle sizing instrument that is fast, works over the most important particle sizes, and avoids some of the issues that plague other optical particle sizers. Unfortunately it sees some particles much smaller than they really are, likely because they heat up and evaporate. We show a crude correction and speculate why these particles heat up much more than expected.
Fan Mei, Steven Spielman, Susanne Hering, Jian Wang, Mikhail S. Pekour, Gregory Lewis, Beat Schmid, Jason Tomlinson, and Maynard Havlicek
Atmos. Meas. Tech., 14, 7329–7340,Short summary
This study focuses on understanding a versatile water-based condensation particle counter (vWCPC 3789) performance under various ambient pressure conditions (500–1000 hPa). A vWCPC has the advantage of avoiding health and safety concerns. However, its performance characterization under low pressure is rare but crucial for ensuring successful airborne deployment. This paper provides advanced knowledge of operating a vWCPC 3789 to capture the spatial variations of atmospheric aerosols.
Rebecca A. Wernis, Nathan M. Kreisberg, Robert J. Weber, Yutong Liang, John Jayne, Susanne Hering, and Allen H. Goldstein
Atmos. Meas. Tech., 14, 6533–6550,Short summary
cTAG is a new scientific instrument that measures concentrations of organic chemicals in the atmosphere. cTAG is the first instrument capable of measuring small, light chemicals as well as heavier chemicals and everything in between on a single detector, every hour. In this work we explain how cTAG works and some of the tests we performed to verify that it works properly and reliably. We also present measurements of alkanes that suggest they have three dominant sources in a Bay Area suburb.
Linghan Zeng, Amy P. Sullivan, Rebecca A. Washenfelder, Jack Dibb, Eric Scheuer, Teresa L. Campos, Joseph M. Katich, Ezra Levin, Michael A. Robinson, and Rodney J. Weber
Atmos. Meas. Tech., 14, 6357–6378,Short summary
Three online systems for measuring water-soluble brown carbon are compared. A mist chamber and two different particle-into-liquid samplers were deployed on separate research aircraft targeting wildfires and followed a similar detection method using a long-path liquid waveguide with a spectrometer to measure the light absorption from 300 to 700 nm. Detection limits, signal hysteresis and other sampling issues are compared, and further improvements of these liquid-based systems are provided.
Zixia Liu, Martin Osborne, Karen Anderson, Jamie D. Shutler, Andy Wilson, Justin Langridge, Steve H. L. Yim, Hugh Coe, Suresh Babu, Sreedharan K. Satheesh, Paquita Zuidema, Tao Huang, Jack C. H. Cheng, and James Haywood
Atmos. Meas. Tech., 14, 6101–6118,Short summary
This paper first validates the performance of an advanced aerosol observation instrument POPS against a reference instrument and examines any biases introduced by operating it on a quadcopter drone. The results show the POPS performs relatively well on the ground. The impact of the UAV rotors on the POPS is small at low wind speeds, but when operating under higher wind speeds, larger discrepancies occur. It appears that the POPS measures sub-micron aerosol particles more accurately on the UAV.
Eric A. Wendt, Casey Quinn, Christian L'Orange, Daniel D. Miller-Lionberg, Bonne Ford, Jeffrey R. Pierce, John Mehaffy, Michael Cheeseman, Shantanu H. Jathar, David H. Hagan, Zoey Rosen, Marilee Long, and John Volckens
Atmos. Meas. Tech., 14, 6023–6038,Short summary
Fine particulate matter air pollution is one of the leading contributors to adverse health outcomes on the planet. Here, we describe the design and validation of a low-cost, compact, and autonomous instrument capable of measuring particulate matter levels directly, via mass sampling, and optically, via mass and sunlight extinction measurements. We demonstrate the instrument's accuracy relative to reference measurements and its potential for community-level sampling.
Jiaoshi Zhang, Steven Spielman, Yang Wang, Guangjie Zheng, Xianda Gong, Susanne Hering, and Jian Wang
Atmos. Meas. Tech., 14, 5625–5635,Short summary
In this study, we present a newly developed instrument, the humidity-controlled fast integrated mobility spectrometer (HFIMS), for fast measurements of aerosol hygroscopic growth. The HFIMS can measure the distributions of particle hygroscopic growth factors at six diameters from 35 to 265 nm under five RH levels from 20 to 85 % within 25 min. The HFIMS significantly advances our capability of characterizing the hygroscopic growth of atmospheric aerosols over a wide range of relative humidities.
Johannes Passig, Julian Schade, Robert Irsig, Lei Li, Xue Li, Zhen Zhou, Thomas Adam, and Ralf Zimmermann
Atmos. Meas. Tech., 14, 4171–4185,Short summary
Ships are major sources of air pollution; however, monitoring of ship emissions outside harbours is a challenging task. We optimized single-particle mass spectrometry (SPMS) for the detection of bunker fuel emissions and demonstrate the detection of individual ship plumes from more than 10 km in distance. The approach works independently of background air pollution and also when ships use exhaust-cleaning scrubbers. We discuss the potential and limits of SPMS-based monitoring of ship plumes.
Mengying Bao, Yan-Lin Zhang, Fang Cao, Yu-Chi Lin, Yuhang Wang, Xiaoyan Liu, Wenqi Zhang, Meiyi Fan, Feng Xie, Robert Cary, Joshua Dixon, and Lihua Zhou
Atmos. Meas. Tech., 14, 4053–4068,Short summary
We introduce a two-wavelength method for brown C measurements with a modified Sunset carbon analyzer. We defined the enhanced concentrations and gave the possibility of providing an indicator of brown C. Compared with the strong local sources of organic and elemental C, we found that differences in EC mainly originated from regional transport. Biomass burning emissions significantly contributed to high differences in EC concentrations during the heavy biomass burning periods.
Candice L. Sirmollo, Don R. Collins, Jordan M. McCormick, Cassandra F. Milan, Matthew H. Erickson, James H. Flynn, Rebecca J. Sheesley, Sascha Usenko, Henry W. Wallace, Alexander A. T. Bui, Robert J. Griffin, Matthew Tezak, Sean M. Kinahan, and Joshua L. Santarpia
Atmos. Meas. Tech., 14, 3351–3370,Short summary
The newly developed portable 1 m3 CAGE chamber systems were characterized using data acquired during a 2-month field study in 2016 in a forested area north of Houston, TX, USA. Concentrations of several oxidant and organic compounds measured in the chamber were found to closely agree with those calculated with a zero-dimensional model. By tracking the modes of injected monodisperse particles, a pattern change was observed for hourly averaged growth rates between late summer and early fall.
Ningjin Xu and Don R. Collins
Atmos. Meas. Tech., 14, 2891–2906,Short summary
Oxidation flow reactors (OFRs) are frequently used to study atmospheric chemistry and aerosol formation by accelerating by up to 10 000 times the reactions that can take hours, days, or even weeks in the atmosphere. Here we present the design and evaluation of a new all-Teflon OFR. The computational, laboratory, and field use data we present demonstrate that the PFA OFR is suitable for a range of applications, including the study of rapidly changing ambient concentrations.
Lars E. Kalnajs, Sean M. Davis, J. Douglas Goetz, Terry Deshler, Sergey Khaykin, Alex St. Clair, Albert Hertzog, Jerome Bordereau, and Alexey Lykov
Atmos. Meas. Tech., 14, 2635–2648,Short summary
This work introduces a novel instrument system for high-resolution atmospheric profiling, which lowers and retracts a suspended instrument package beneath drifting long-duration balloons. During a 100 d circumtropical flight, the instrument collected over a hundred 2 km profiles of temperature, water vapor, clouds, and aerosol at 1 m resolution, yielding unprecedented geographic sampling and vertical resolution measurements of the tropical tropopause layer.
Demetrios Pagonis, Pedro Campuzano-Jost, Hongyu Guo, Douglas A. Day, Melinda K. Schueneman, Wyatt L. Brown, Benjamin A. Nault, Harald Stark, Kyla Siemens, Alex Laskin, Felix Piel, Laura Tomsche, Armin Wisthaler, Matthew M. Coggon, Georgios I. Gkatzelis, Hannah S. Halliday, Jordan E. Krechmer, Richard H. Moore, David S. Thomson, Carsten Warneke, Elizabeth B. Wiggins, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 1545–1559,Short summary
We describe the airborne deployment of an extractive electrospray time-of-flight mass spectrometer (EESI-MS). The instrument provides a quantitative 1 Hz measurement of the chemical composition of organic aerosol up to altitudes of 7 km, with single-compound detection limits as low as 50 ng per standard cubic meter.
Xiaona Shang, Ling Li, Xinlian Zhang, Huihui Kang, Guodong Sui, Gehui Wang, Xingnan Ye, Hang Xiao, and Jianmin Chen
Atmos. Meas. Tech., 14, 1037–1045,Short summary
Oxidative stress can be used to evaluate not only adverse health effects but also adverse ecological effects. However, little research uses eco-toxicological assay to assess the risks posed by particle matter to non-human biomes. One important reason might be that the concentration of toxic components of atmospheric particles is far below the high detection limit of eco-toxic measurement. To solve the rapid detection problem, we extended a VACES for ecotoxicity aerosol measurement.
Joan Stude, Heinfried Aufmhoff, Hans Schlager, Markus Rapp, Frank Arnold, and Boris Strelnikov
Atmos. Meas. Tech., 14, 983–993,Short summary
In this paper we describe the instrument ROMARA and show data from the first flight on a research rocket. On the way through the atmosphere, the instrument detects positive and negative, natural occurring ions before returning back to ground. ROMARA was successfully launched together with other instruments into a special radar echo. We detected typical, light ions of positive and negative charge and heavy negative ions, but no heavy positive ions.
Rob L. Modini, Joel C. Corbin, Benjamin T. Brem, Martin Irwin, Michele Bertò, Rosaria E. Pileci, Prodromos Fetfatzis, Kostas Eleftheriadis, Bas Henzing, Marcel M. Moerman, Fengshan Liu, Thomas Müller, and Martin Gysel-Beer
Atmos. Meas. Tech., 14, 819–851,Short summary
Extinction-minus-scattering is an important method for measuring aerosol light absorption, but its application in the field presents a number of challenges. A recently developed instrument based on this method – the CAPS PMssa – has the potential to overcome some of these challenges. We present a compilation of theory, lab measurements, and field examples to characterize this instrument and show the conditions under which it can deliver reliable absorption measurements for atmospheric aerosols.
Carolyn E. Jordan, Ryan M. Stauffer, Brian T. Lamb, Charles H. Hudgins, Kenneth L. Thornhill, Gregory L. Schuster, Richard H. Moore, Ewan C. Crosbie, Edward L. Winstead, Bruce E. Anderson, Robert F. Martin, Michael A. Shook, Luke D. Ziemba, Andreas J. Beyersdorf, Claire E. Robinson, Chelsea A. Corr, and Maria A. Tzortziou
Atmos. Meas. Tech., 14, 695–713,Short summary
First field data from a custom-built in situ instrument measuring hyperspectral (300–700 nm, 0.8 nm resolution) ambient atmospheric aerosol extinction are presented. The advantage of this capability is that it can be directly linked to other in situ techniques that measure physical and chemical properties of atmospheric aerosols. Second-order polynomials provided a better fit to the data than traditional power law fits, yielding greater discrimination among distinct ambient aerosol populations.
Carolyn E. Jordan, Ryan M. Stauffer, Brian T. Lamb, Michael Novak, Antonio Mannino, Ewan C. Crosbie, Gregory L. Schuster, Richard H. Moore, Charles H. Hudgins, Kenneth L. Thornhill, Edward L. Winstead, Bruce E. Anderson, Robert F. Martin, Michael A. Shook, Luke D. Ziemba, Andreas J. Beyersdorf, Claire E. Robinson, Chelsea A. Corr, and Maria A. Tzortziou
Atmos. Meas. Tech., 14, 715–736,Short summary
In situ measurements of ambient atmospheric aerosol hyperspectral (300–700 nm) optical properties (extinction, total absorption, water- and methanol-soluble absorption) were observed around the Korean peninsula. Such in situ observations provide a direct link between ambient aerosol optical properties and their physicochemical properties. The benefit of hyperspectral measurements is evident as simple mathematical functions could not fully capture the observed spectral detail of ambient aerosols.
Cyril Brunner and Zamin A. Kanji
Atmos. Meas. Tech., 14, 269–293,Short summary
Subvisual microscopic particles in the atmosphere are needed to act as seeds for cloud droplets or ice crystals to form. The microscopic particles, called ice-nucleating particles (INPs), form ice crystals and are rare, and their properties are not well understood, in part because measuring them is challenging and time consuming, and to date has not been automated. Here, we present the first online instrument that can continuously and autonomously measure INP concentration at 243 K.
Adnan Masic, Dzevad Bibic, Boran Pikula, Almir Blazevic, Jasna Huremovic, and Sabina Zero
Atmos. Meas. Tech., 13, 6427–6443,Short summary
Optical-based particulate matter sensors offer some advantages: price (especially low-cost sensors), time and space resolution, but they are less accurate than reference instruments. Understanding their performance and limitations is crucial for wider adoption. This is a case study for strong and mild air pollution done in Sarajevo, Bosnia-Herzegovina. Tested optical sensors were found to be generally acceptable in this study, but proper calibration is required for getting reliable data.
Hans-Christian Clemen, Johannes Schneider, Thomas Klimach, Frank Helleis, Franziska Köllner, Andreas Hünig, Florian Rubach, Stephan Mertes, Heike Wex, Frank Stratmann, André Welti, Rebecca Kohl, Fabian Frank, and Stephan Borrmann
Atmos. Meas. Tech., 13, 5923–5953,Short summary
We improved the efficiency of a single-particle mass spectrometer with a newly developed aerodynamic lens system, delayed ion extraction, and better electric shielding. The new components result in significantly improved particle analysis and sample statistics. This is particularly important for measurements of low-number-density particles, such as ice-nucleating particles, and for aircraft-based measurements at high altitudes or where high temporal and spatial resolution is required.
Karin Ardon-Dryer, Yuval Dryer, Jake N. Williams, and Nastaran Moghimi
Atmos. Meas. Tech., 13, 5441–5458,Short summary
The PurpleAir PA-II is a low-cost sensor for monitoring changes in the concentrations of particulate matter of various sizes. This study examined the behaviour of multiple PA-II units in four locations in the USA under atmospheric conditions when exposed to a variety of pollutants and different PM2.5 concentrations. The PA-II unit is a promising tool for measuring PM2.5 concentrations and identifying relative concentration changes, as long as the PA-II PM2.5 values can be corrected.
Cui-Ping Su, Xing Peng, Xiao-Feng Huang, Li-Wu Zeng, Li-Ming Cao, Meng-Xue Tang, Yao Chen, Bo Zhu, Yishi Wang, and Ling-Yan He
Atmos. Meas. Tech., 13, 5407–5422,Short summary
Online instruments have been widely applied for the measurement of PM2.5 and its chemical components; however, these instruments have a major shortcoming in terms of the limited number (or lack) of species in field measurements. To this end, a new mass closure PM2.5 online-integrated system was developed and applied in this work to achieve more comprehensive information on chemical species in PM2.5, thus providing a powerful tool for PM2.5 long-term daily measurement and source apportionment.
Anna K. Tobler, Alicja Skiba, Dongyu S. Wang, Philip Croteau, Katarzyna Styszko, Jarosław Nęcki, Urs Baltensperger, Jay G. Slowik, and André S. H. Prévôt
Atmos. Meas. Tech., 13, 5293–5301,Short summary
Some quadrupole aerosol chemical speciation monitors (Q-ACSMs) have had issues with the quantification of particulate chloride, resulting in apparent negative chloride concentrations. We can show that this is due to the different behavior of Cl+ and HCl+, and we present a correction for the more accurate quantification of chloride. The correction can be applied to measurements in environments where the particulate chloride is dominated by NH4Cl.
Khanneh Wadinga Fomba, Nabil Deabji, Sayf El Islam Barcha, Ibrahim Ouchen, El Mehdi Elbaramoussi, Rajaa Cherkaoui El Moursli, Mimoun Harnafi, Souad El Hajjaji, Abdelwahid Mellouki, and Hartmut Herrmann
Atmos. Meas. Tech., 13, 4773–4790,Short summary
As air quality monitoring networks often sample aerosol particles on quartz filters, the development and applicability of analytical methods with quartz filters are becoming important. In this study different filter preparation methods (e.g., baking, acid digestion) were investigated for quantifying trace metals on quartz and polycarbonate filters, and cloud water using the total reflection X-Ray fluorescence (TXRF) technique, with low detection limits of about 0.3 ng cm−3 for some elements.
Luka Drinovec, Jean Sciare, Iasonas Stavroulas, Spiros Bezantakos, Michael Pikridas, Florin Unga, Chrysanthos Savvides, Bojana Višić, Maja Remškar, and Griša Močnik
Atmos. Meas. Tech., 13, 3799–3813,Short summary
Atmospheric mineral dust influences Earth's radiative budget, has adverse health effects, and affects regulatory PM10 concentrations. We present a highly time resolved online technique for quantification of mineral dust concentration in ambient air. The technique uses a virtual impactor to concentrate coarse particles, where absorption is then measured using a filter photometer. The method was tested in the field at a regional background site on Cyprus.
Jan-David Förster, Christian Gurk, Mark Lamneck, Haijie Tong, Florian Ditas, Sarah S. Steimer, Peter A. Alpert, Markus Ammann, Jörg Raabe, Markus Weigand, Benjamin Watts, Ulrich Pöschl, Meinrat O. Andreae, and Christopher Pöhlker
Atmos. Meas. Tech., 13, 3717–3729,Short summary
A gas flow system coupled with a microreactor for X-ray microspectroscopy is presented. Its core objective is to mimic the atmospheric processing of aerosol particles under laboratory conditions in a controlled gas-phase environment and allow in situ observations with high spatial and chemical resolution. We here emphasize its analytical capabilities and show initial results from hydration–dehydration experiments and the observation of water ice at low temperature and high relative humidity.
Sergej Molleker, Frank Helleis, Thomas Klimach, Oliver Appel, Hans-Christian Clemen, Antonis Dragoneas, Christian Gurk, Andreas Hünig, Franziska Köllner, Florian Rubach, Christiane Schulz, Johannes Schneider, and Stephan Borrmann
Atmos. Meas. Tech., 13, 3651–3660,Short summary
A novel constant-pressure-inlet design for use in airborne aerosol particle mass spectrometry – an aerodynamic lens focuses aerosol particles into a vacuum chamber – is presented. The pressure of a few hectopascals at the lens is precisely controlled over a large flight altitude range up to 21 km. The constant pressure is achieved by changing the inner diameter of a properly scaled flexible O-ring acting as a critical orifice. Particle transmission at various inlet pressures is characterized.
Grace C. E. Porter, Sebastien N. F. Sikora, Michael P. Adams, Ulrike Proske, Alexander D. Harrison, Mark D. Tarn, Ian M. Brooks, and Benjamin J. Murray
Atmos. Meas. Tech., 13, 2905–2921,Short summary
Ice-nucleating particles affect cloud development, lifetime, and radiative properties. Hence it is important to know the abundance of INPs throughout the atmosphere. Here we present the development and application of a radio-controlled payload capable of collecting size-resolved aerosol from a tethered balloon for the primary purpose of offline INP analysis. Test data are presented from four locations: southern Finland, northern England, Svalbard, and southern England.
Jiacheng Zhou, Xuezhe Xu, Weixiong Zhao, Bo Fang, Qianqian Liu, Yuanqing Cai, Weijun Zhang, Dean S. Venables, and Weidong Chen
Atmos. Meas. Tech., 13, 2623–2634,Short summary
We report the first demonstration of a humidified cavity-enhanced albedometer (H-CEA) that combines a broadband cavity-enhanced aerosol albedometer with a humidigraph system for simultaneous and accurate measurements of multiple optical hygroscopic parameters (f(RH)ext,scat,abs,ω) at λ = 532 nm. The instrument is suitable for operating under high RH-conditions and has sampling advantages over independent measurements of different parameters with different instruments.
Antonio Spanu, Maximilian Dollner, Josef Gasteiger, T. Paul Bui, and Bernadett Weinzierl
Atmos. Meas. Tech., 13, 1963–1987,Short summary
This study investigates how the airflow around wing-mounted instruments on fast-flying aircraft affects aerosol and cloud measurements. It combines airborne data with numerical simulations and shows that particle speed, particle concentration, and shape of water droplets are modified by the airflow. The proposed correction strategy for optical particle counters and optical array probes considers airflow effects and significantly reduces errors of derived ambient aerosol and cloud properties.
Hong Ku Lee, Handol Lee, and Kang-Ho Ahn
Atmos. Meas. Tech., 13, 1551–1562,Short summary
We developed a nanoparticle sizer (NPS), consisting of a multi-port differential mobility analyzer (MP-DMA) with 12 sampling ports and multi-condensation particle counters (M-CPCs) for fast measurement of particle size distribution. The NPS can successfully capture the changes in particle size distribution under fast-changing particle concentration conditions. In this study, particle emissions from cooking activity are analyzed as an exemplary real-world application.
Eric Sauvageat, Yanick Zeder, Kevin Auderset, Bertrand Calpini, Bernard Clot, Benoît Crouzy, Thomas Konzelmann, Gian Lieberherr, Fiona Tummon, and Konstantina Vasilatou
Atmos. Meas. Tech., 13, 1539–1550,Short summary
We present the first validation of the only operational automatic pollen monitoring system based on holography, the Swisens Poleno. The device produces real-time images of coarse aerosols, and by applying a machine learning algorithm we identify a range of pollen taxa with accuracy >90 %. The device was further validated in controlled chamber experiments to verify the counting ability and the performance of additional fluorescence measurements, which can further be used in pollen identification.
Leigh R. Crilley, Ajit Singh, Louisa J. Kramer, Marvin D. Shaw, Mohammed S. Alam, Joshua S. Apte, William J. Bloss, Lea Hildebrandt Ruiz, Pingqing Fu, Weiqi Fu, Shahzad Gani, Michael Gatari, Evgenia Ilyinskaya, Alastair C. Lewis, David Ng'ang'a, Yele Sun, Rachel C. W. Whitty, Siyao Yue, Stuart Young, and Francis D. Pope
Atmos. Meas. Tech., 13, 1181–1193,Short summary
There is considerable interest in using low-cost optical particle counters (OPCs) for particle mass measurements; however, there is no agreed upon method with respect to calibration. Here we exploit a number of datasets globally to demonstrate that particle composition and relative humidity are the key factors affecting measured concentrations from a low-cost OPC, and we present a simple correction methodology that corrects for this influence.
Ying Chen, Viacheslav Kozlovskiy, Xubing Du, Jinnuo Lv, Sergei Nikiforov, Jiajun Yu, Alexander Kolosov, Wei Gao, Zhen Zhou, Zhengxu Huang, and Lei Li
Atmos. Meas. Tech., 13, 941–949,Short summary
Ion delayed extraction technique in single particle mass spectrometry has been found to improve the mass resolution of instruments. Through further research, it was found that it can improve the aerosol particle detection efficiency because it can eliminate the influence of the electrical field on the charged aerosol trajectory so that more effective data can be obtained in a short time in laboratory or field atmospheric aerosol research, especially in low-concentration aerosol sample analysis.
Nina Löbs, Cybelli G. G. Barbosa, Sebastian Brill, David Walter, Florian Ditas, Marta de Oliveira Sá, Alessandro C. de Araújo, Leonardo R. de Oliveira, Ricardo H. M. Godoi, Stefan Wolff, Meike Piepenbring, Jürgen Kesselmeier, Paulo Artaxo, Meinrat O. Andreae, Ulrich Pöschl, Christopher Pöhlker, and Bettina Weber
Atmos. Meas. Tech., 13, 153–164,Short summary
Bioaerosols are considered to play a relevant role in atmospheric processes, but their sources, properties, and spatiotemporal distribution in the atmosphere are not yet well characterized. Measurement data on the release of fungal spores under natural conditions are also sparse. Here, we present an experimental approach to analyze and quantify the spore release from fungi and other spore-producing organisms under natural and laboratory conditions.
Helen R. Smith, Zbigniew Ulanowski, Paul H. Kaye, Edwin Hirst, Warren Stanley, Richard Kaye, Andreas Wieser, Chris Stopford, Maria Kezoudi, Joseph Girdwood, Richard Greenaway, and Robert Mackenzie
Atmos. Meas. Tech., 12, 6579–6599,Short summary
The Universal Cloud and Aerosol Sounding System (UCASS) is a low-cost miniature optical particle counter (OPC) capable of sizing particles in the size range 0.4–40 μm. The open-geometry design makes the instrument suitable for deployment on balloon-borne sounding systems, dropsonde systems or as part of an unmanned aerial vehicle (UAV). Laboratory and field experiments show good agreement with reference instruments in a range of cloudy and dusty environments.
Ahangar, F. E., Freedman, F. R., and Venkatram, A.: Using Low-Cost Air Quality Sensor Networks to Improve the Spatial and Temporal Resolution of Concentration Maps, Int. J. Env. Res. Pub. He., 16, 1252, https://doi.org/10.3390/ijerph16071252, 2019.
Apte, J. S., Messier, K. P., Gani, S., Brauer, M., Kirchstetter, T. W., Lunden, M. M., Marshall, J. D., Portier, C. J., Vermeulen, R. C. H., and Hamburg, S. P.: High-Resolution Air Pollution Mapping with Google Street View Cars: Exploiting Big Data, Environ. Sci. Technol., 51, 6999–7008, https://doi.org/10.1021/acs.est.7b00891, 2017. 2017.
Barkjohn, K. K., Gantt, B., and Clements, A. L.: Development and application of a United States-wide correction for PM2.5 data collected with the PurpleAir sensor, Atmos. Meas. Tech., 14, 4617–4637, https://doi.org/10.5194/amt-14-4617-2021, 2021.
Bauerová, P., Šindelářová, A., Rychlík, Š., Novák, Z., and Keder, J.: Low-Cost Air Quality Sensors: One-Year Field Comparative Measurement of Different Gas Sensors and Particle Counters with Reference Monitors at Tušimice Observatory, Atmosphere, 11, 492, https://doi.org/10.3390/atmos11050492, 2020.
Bi, J., Stowell, J., Seto, E. Y. W., English, P. B., Al-Hamdan, M. Z., Kinney, P. L., Freedman, F. R., and Liu, Y.: Contribution of low-cost sensor measurements to the prediction of PM2.5 levels: A case study in Imperial County, California, USA, Environ. Res., 180, 108810, https://doi.org/10.1016/j.envres.2019.108810, 2020.
Considine, E. M., Reid, C. E., Ogletree, M. R., and Dye, T.: Improving accuracy of air pollution exposure measurements: Statistical correction of a municipal low-cost airborne particulate matter sensor network, Environ. Pollut., 268, 115833, https://doi.org/10.1016/j.envpol.2020.115833, 2021.
Datta, A., Saha, A., Zamora, M. L., Buehler, C., Hao, L., Xiong, F., Gentner, D. R., and Koehler, K.: Statistical field calibration of a low-cost PM2.5 monitoring network in Baltimore, Atmos. Environ., 242, 117761, https://doi.org/10.1016/j.atmosenv.2020.117761, 2020.
Di Antonio, A., Popoola, O. A. M., Ouyang, B., Saffell, J., and Jones, R. L.: Developing a Relative Humidity Correction for Low-Cost Sensors Measuring Ambient Particulate Matter, Sensors-Basel, 18, 2790, https://doi.org/10.3390/s18092790, 2018.
Duvall, R., Clements, A., Hagler, G., Kamal, A., Kilaru, V., Goodman, L., Frederick, S., Barkjohn, K. J., VonWald, I., Greene, D., and Dye, T.: Performance Testing Protocols, Metrics, and Target Values for Fine Particulate Matter Air Sensors: Use in Ambient, Outdoor, Fixed Site, Non-Regulatory Supplemental and Informational Monitoring Applications, U.S. EPA Office of Research and Development, Washington, DC, EPA/600/R-20/280, 2021.
Feenstra, B., Papapostolou, V., Hasheminassab, S., Zhang, H., Boghossian, B. D., Cocker, D., and Polidori, A.: Performance evaluation of twelve low-cost PM2.5 sensors at an ambient air monitoring site, Atmos. Environ., 216, 116946, https://doi.org/10.1016/j.atmosenv.2019.116946, 2019.
Gao, M., Cao, J., and Seto, E.: A distributed network of low-cost continuous reading sensors to measure spatiotemporal variations of PM2.5 in Xi'an, China, Environ. Pollut., 199, 56–65, 2015.
Giordano, M. R., Malings, C., Pandis, S. N., Presto, A. A., McNeill, V. F., Westervelt, D. M., Beekmann, M., and Subramanian, R.: From low-cost sensors to high-quality data: A summary of challenges and best practices for effectively calibrating low-cost particulate matter mass sensors, J. Aerosol Sci., 158, 105833, https://doi.org/10.1016/j.jaerosci.2021.105833, 2021.
Hasenfratz, D., Saukh, O., Walser, C., Hueglin, C., Fierz, M., Arn, T., Beutel, J., and Thiele, L.: Deriving high-resolution urban air pollution maps using mobile sensor nodes, Pervasive Mob. Comput., 16, 268–285, 2015.
Holstius, D. M., Pillarisetti, A., Smith, K. R., and Seto, E.: Field calibrations of a low-cost aerosol sensor at a regulatory monitoring site in California, Atmos. Meas. Tech., 7, 1121–1131, https://doi.org/10.5194/amt-7-1121-2014, 2014.
Jayaratne, R., Liu, X., Ahn, K.-H., Asumadu-Sakyi, A., Fisher, G., Gao, J., Mabon, A., Mazaheri, M., Mullins, B., Nyaku, M., Ristovski, Z., Scorgie, Y., Thai, P., Dunbabin, M., and Morawska, L.: Low-cost PM2.5 Sensors: An Assessment of Their Suitability for Various Applications, Aerosol Air Qual. Res., 20, 520–532, https://doi.org/10.4209/aaqr.2018.10.0390, 2020.
Jiao, W., Hagler, G., Williams, R., Sharpe, R., Brown, R., Garver, D., Judge, R., Caudill, M., Rickard, J., Davis, M., Weinstock, L., Zimmer-Dauphinee, S., and Buckley, K.: Community Air Sensor Network (CAIRSENSE) project: evaluation of low-cost sensor performance in a suburban environment in the southeastern United States, Atmos. Meas. Tech., 9, 5281–5292, https://doi.org/10.5194/amt-9-5281-2016, 2016.
Karagulian, F., Barbiere, M., Kotsev, A., Spinelle, L., Gerboles, M., Lagler, F., Redon, N., Crunaire, S., and Borowiak, A.: Review of the Performance of Low-Cost Sensors for Air Quality Monitoring, Atmosphere, 10, 506, https://doi.org/10.3390/atmos10090506, 2019.
Kumar, V. and Sahu, M.: Evaluation of nine machine learning regression algorithms for calibration of low-cost PM2.5 sensor, J. Aerosol Sci., 157, 105809, https://doi.org/10.1016/j.jaerosci.2021.105809, 2021.
Kuula, J., Friman, M., Helin, A., Niemi, J. V., Aurela, M., Timonen, H., and Saarikoski, S.: Utilization of scattering and absorption-based particulate matter sensors in the environment impacted by residential wood combustion, J. Aerosol Sci., 150, 105671, https://doi.org/10.1016/j.jaerosci.2020.105671, 2020.
Levy Zamora, M., Xiong, F., Gentner, D., Kerkez, B., Kohrman-Glaser, J., and Koehler, K.: Field and Laboratory Evaluations of the Low-Cost Plantower Particulate Matter Sensor, Environ. Sci. Technol., 53, 838–849, 2019.
Li, J., Zhang, H., Chao, C.-Y., Chien, C.-H., Wu, C.-Y., Luo, C. H., Chen, L.-J., and Biswas, P.: Integrating low-cost air quality sensor networks with fixed and satellite monitoring systems to study ground-level PM2.5, Atmos. Environ., 223, 117293, https://doi.org/10.1016/j.atmosenv.2020.117293, 2020.
Malings, C., Tanzer, R., Hauryliuk, A., Saha, P. K., Robinson, A. L., Presto, A. A., and Subramanian, R.: Fine particle mass monitoring with low-cost sensors: Corrections and long-term performance evaluation, Aerosol Sci. Tech., 54, 160–174, 2020.
Mazaheri, M., Clifford, S., Yeganeh, B., Viana, M., Rizza, V., Flament, R., Buonanno, G., and Morawska, L.: Investigations into factors affecting personal exposure to particles in urban microenvironments using low-cost sensors, Environ. Int., 120, 496–504, 2018.
Mukherjee, A., Stanton, L. G., Graham, A. R., and Roberts, P. T.: Assessing the Utility of Low-Cost Particulate Matter Sensors over a 12-Week Period in the Cuyama Valley of California, Sensors, 17, 1805, https://doi.org/10.3390/s17081805, 2017.
Papapostolou, V., Zhang, H., Feenstra, B. J., and Polidori, A.: Development of an environmental chamber for evaluating the performance of low-cost air quality sensors under controlled conditions, Atmos. Environ., 171, 82–90, https://doi.org/10.1016/j.atmosenv.2017.10.003, 2017.
Stanton, L. G., Pavlovic, N. R., DeWinter, J. L., and Hafner, H.: Approaches to Air Sensor Calibration, Air Sensors International Conference 2018, Oakland, CA, 12–14 September 2018.
Stavroulas, I., Grivas, G., Michalopoulos, P., Liakakou, E., Bougiatioti, A., Kalkavouras, P., Fameli, K. M., Hatzianastassiou, N., Mihalopoulos, N., and Gerasopoulos, E.: Field Evaluation of Low-Cost PM Sensors (Purple Air PA-II) Under Variable Urban Air Quality Conditions, in Greece, Atmosphere, 11, 926, https://doi.org/10.3390/atmos11090926, 2020.
Tryner, J., L'Orange, C., Mehaffy, J., Miller-Lionberg, D., Hofstetter, J. C., Wilson, A., and Volckens, J.: Laboratory evaluation of low-cost PurpleAir PM monitors and in-field correction using co-located portable filter samplers, Atmos. Environ., 220, 117067, https://doi.org/10.1016/j.atmosenv.2019.117067, 2020.
Williams, R., Duvall, R., Kilaru, V., Hagler, G., Hassinger, L., Benedict, K., Rice, J., Kaufman, A., Judge, R., Pierce, G., Allen, G., Bergin, M., Cohen, R. C., Fransioli, P., Gerboles, M., Habre, R., Hannigan, M., Jack, D., Louie, P., Martin, N. A., Penza, M., Polidori, A., Subramanian, R., Ray, K., Schauer, J., Seto, E., Thurston, G., Turner, J., Wexler, A. S., and Ning, Z.: Deliberating performance targets workshop: Potential paths for emerging PM2.5 and O3 air sensor progress, Atmos. Environ.: X, 2, 100031, https://doi.org/10.1016/j.aeaoa.2019.100031, 2019.
Williams, R., Nash, D., Hagler, G., Benedict, K., MacGregor, I., Seay, B., Lawrence, M., and Dye, T.: Peer Review and Supporting Literature Review of Air Sensor Technology Performance Targets, U.S. EPA Office of Research and Development, Washington, DC, EPA 600/R-18/324, 2018.
Zamora, M. L., Rice, J., and Koehler, K.: One year evaluation of three low-cost PM2.5 monitors, Atmos. Environ., 235, 117615, https://doi.org/10.1016/j.atmosenv.2020.117615, 2020.
Zheng, T., Bergin, M. H., Johnson, K. K., Tripathi, S. N., Shirodkar, S., Landis, M. S., Sutaria, R., and Carlson, D. E.: Field evaluation of low-cost particulate matter sensors in high- and low-concentration environments, Atmos. Meas. Tech., 11, 4823–4846, https://doi.org/10.5194/amt-11-4823-2018, 2018.
Zikova, N., Masiol, M., Chalupa, D., Rich, D., Ferro, A., and Hopke, P.: Estimating Hourly Concentrations of PM2.5 across a Metropolitan Area Using Low-Cost Particle Monitors, Sensors-Basel, 17, 1922, https://doi.org/10.3390/s17081922, 2017.
Zou, Y., Clark, J. D., and May, A. A.: Laboratory evaluation of the effects of particle size and composition on the performance of integrated devices containing Plantower particle sensors, Aerosol Sci. Tech., 55, 848–858, 2021a.
Zou, Y., Clark, J. D., and May, A. A.: A systematic investigation on the effects of temperature and relative humidity on the performance of eight low-cost particle sensors and devices, J. Aerosol Sci., 152, 105715, https://doi.org/10.1016/j.jaerosci.2020.105715, 2021b.
Zusman, M., Schumacher, C. S., Gassett, A. J., Spalt, E. W., Austin, E., Larson, T. V., Carvlin, G., Seto, E., Kaufman, J. D., and Sheppard, L.: Calibration of low-cost particulate matter sensors: Model development for a multi-city epidemiological study, Environ. Int., 134, 105329, https://doi.org/10.1016/j.envint.2019.105329, 2020.
Understanding and improving the quality of data generated from low-cost air quality sensors are crucial steps in using these sensors. This work investigates how averaging time, choice of reference instrument, and the observation of higher pollutant concentrations can impact the perceived performance of low-cost sensors in an evaluation. The influence of these factors should be considered when comparing one sensor to another or determining if a sensor can produce data that fit a specific need.
Understanding and improving the quality of data generated from low-cost air quality sensors are...