Performance Evaluation and Community Application of Low-Cost Sensors for Ozone and Nitrogen Dioxide

This study reports on the performance of electrochemical-based low-cost sensors and their use in a community application. CairClip sensors were collocated with federal reference and equivalent methods and operated in a network of sites by citizen scientists (community members) in Houston, Texas and Denver, Colorado, under the umbrella of the NASA-led DISCOVER-AQ Earth Venture Mission. Measurements were focused on ozone (O-3) and nitrogen dioxide (NO2). The performance evaluation showed that the CairClip O-3/NO2 sensor provided a consistent measurement response to that of reference monitors (r(2) = 0.79 in Houston; r(2) = 0.72 in Denver) whereas the CairClip NO2 sensor measurements showed no agreement to reference measurements. The CairClip O-3/NO2 sensor data from the citizen science sites compared favorably to measurements at nearby reference monitoring sites. This study provides important information on data quality from low-cost sensor technologies and is one of few studies that reports sensor data collected directly by citizen scientists.