Next Article in Journal
Evaluation of the SOA Formation in the Reaction of Furfural with Atmospheric Oxidants
Previous Article in Journal
Grazing under Irrigation Affects N2O-Emissions Substantially in South Africa
Open AccessEditor’s ChoiceArticle

Field Evaluation of Low-Cost PM Sensors (Purple Air PA-II) Under Variable Urban Air Quality Conditions, in Greece

1
Institute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, Greece
2
Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Heraklion, Greece
3
Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110 Ioannina, Greece
*
Authors to whom correspondence should be addressed.
Atmosphere 2020, 11(9), 926; https://doi.org/10.3390/atmos11090926
Received: 27 July 2020 / Revised: 20 August 2020 / Accepted: 25 August 2020 / Published: 29 August 2020
(This article belongs to the Section Air Quality)
Recent advances in particle sensor technologies have led to an increased development and utilization of low-cost, compact, particulate matter (PM) monitors. These devices can be deployed in dense monitoring networks, enabling an improved characterization of the spatiotemporal variability in ambient levels and exposure. However, the reliability of their measurements is an important prerequisite, necessitating rigorous performance evaluation and calibration in comparison to reference-grade instrumentation. In this study, field evaluation of Purple Air PA-II devices (low-cost PM sensors) is performed in two urban environments and across three seasons in Greece, in comparison to different types of reference instruments. Measurements were conducted in Athens (the largest city in Greece with nearly four-million inhabitants) for five months spanning over the summer of 2019 and winter/spring of 2020 and in Ioannina, a medium-sized city in northwestern Greece (100,000 inhabitants) during winter/spring 2019–2020. The PM2.5 sensor output correlates strongly with reference measurements (R2 = 0.87 against a beta attenuation monitor and R2 = 0.98 against an optical reference-grade monitor). Deviations in the sensor-reference agreement are identified as mainly related to elevated coarse particle concentrations and high ambient relative humidity. Simple and multiple regression models are tested to compensate for these biases, drastically improving the sensor’s response. Large decreases in sensor error are observed after implementation of models, leading to mean absolute percentage errors of 0.18 and 0.12 for the Athens and Ioannina datasets, respectively. Overall, a quality-controlled and robustly evaluated low-cost network can be an integral component for air quality monitoring in a smart city. Case studies are presented along this line, where a network of PA-II devices is used to monitor the air quality deterioration during a peri-urban forest fire event affecting the area of Athens and during extreme wintertime smog events in Ioannina, related to wood burning for residential heating. View Full-Text
Keywords: particulate matter; PM2.5; air quality; low-cost sensors; optical particle counter particulate matter; PM2.5; air quality; low-cost sensors; optical particle counter
Show Figures

Figure 1

MDPI and ACS Style

Stavroulas, I.; Grivas, G.; Michalopoulos, P.; Liakakou, E.; Bougiatioti, A.; Kalkavouras, P.; Fameli, K.M.; Hatzianastassiou, N.; Mihalopoulos, N.; Gerasopoulos, E. Field Evaluation of Low-Cost PM Sensors (Purple Air PA-II) Under Variable Urban Air Quality Conditions, in Greece. Atmosphere 2020, 11, 926.

AMA Style

Stavroulas I, Grivas G, Michalopoulos P, Liakakou E, Bougiatioti A, Kalkavouras P, Fameli KM, Hatzianastassiou N, Mihalopoulos N, Gerasopoulos E. Field Evaluation of Low-Cost PM Sensors (Purple Air PA-II) Under Variable Urban Air Quality Conditions, in Greece. Atmosphere. 2020; 11(9):926.

Chicago/Turabian Style

Stavroulas, Iasonas; Grivas, Georgios; Michalopoulos, Panagiotis; Liakakou, Eleni; Bougiatioti, Aikaterini; Kalkavouras, Panayiotis; Fameli, Kyriaki M.; Hatzianastassiou, Nikolaos; Mihalopoulos, Nikolaos; Gerasopoulos, Evangelos. 2020. "Field Evaluation of Low-Cost PM Sensors (Purple Air PA-II) Under Variable Urban Air Quality Conditions, in Greece" Atmosphere 11, no. 9: 926.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop