1 research outputs found
Hyperlocal Air Pollution in London: Validating Low-Cost Sensors for Mobile Measurements from Vehicles
This study assesses low-cost sensors (LCS) for the mobile
monitoring
of air quality, which has thus far been scarcely investigated. NO2 and PM2.5 were measured using LCS and higher-grade
instruments while driving across various environments in London (943
km) and northern Europe (2923 km), including urban areas, motorways,
and tunnels. The data were classified according to the environment
where the measurements were carried out, and the performances of LCS
and higher-grade instruments were compared. Results indicate that
the performances of the sensors were influenced by the rate of change
in pollutant concentration in different environments and not by vehicle
speed. Excluding tunnel environments, overall, the particulate matter
sensors correlated better with their higher-grade instrument than
the electrochemical (EC) sensors, with R2 values from 0.90–0.96 in the different environments, compared
with 0.39–0.72 for the EC sensors. Tunnels presented a unique
opportunity to test the time response of the systems, given the rapid
change in concentration upon entering, and all sensors showed limited
response times. This is the first time that EC NO2 sensors
have been rigorously tested against reference monitors while mobile.
Their absolute measurements appear unaffected by movement; however,
their time resolution may not be high enough for mobile monitoring
in highly variable environments