Long-term evaluation of air sensor technology under ambient conditions in Denver, Colorado
<p>Air pollution sensors are quickly proliferating for use in a wide variety of applications, with a low price point that supports use in high-density networks, citizen science, and individual consumer use. This emerging technology motivates the assessment under real-world conditions, inclu...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-08-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://www.atmos-meas-tech.net/11/4605/2018/amt-11-4605-2018.pdf |
| Summary: | <p>Air pollution sensors are quickly proliferating for use in a wide variety of
applications, with a low price point that supports use in high-density
networks, citizen science, and individual consumer use. This emerging
technology motivates the assessment under real-world conditions, including
varying pollution levels and environmental conditions. A seven-month,
systematic field evaluation of low-cost air pollution sensors was performed
in Denver, Colorado, over 2015–2016; the location was chosen to evaluate the
sensors in a high-altitude, cool, and dry climate. A suite of particulate
matter (PM), ozone (O<sub>3</sub>), and nitrogen dioxide (NO<sub>2</sub>) sensors were
deployed in triplicate and were collocated with federal equivalent method
(FEM) monitors at an urban regulatory site. Sensors were evaluated for their
data completeness, correlation with reference monitors, and ability to
reproduce trends in pollution data, such as daily concentration values and
wind-direction patterns. Most sensors showed high data completeness when data
loggers were functioning properly. The sensors displayed a range of
correlations with reference instruments, from poor to very high (e.g.,
hourly-average PM Pearson correlations with reference measurements varied
from 0.01 to 0.86). Some sensors showed a change in response to laboratory
audits/testing from before the sampling campaign to afterwards, such as
Aeroqual, where the O<sub>3</sub> response slope changed from about 1.2 to 0.6.
Some PM sensors measured wind-direction and time-of-day trends similar to
those measured by reference monitors, while others did not. This study showed
different results for sensor performance than previous studies performed by
the U.S. EPA and others, which could be due to different geographic location,
meteorology, and aerosol properties. These results imply that continued field
testing is necessary to understand emerging air sensing technology.</p> |
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| ISSN: | 1867-1381 1867-8548 |