| 30 Mar 2026
Intercomparison of low-cost sensors via simultaneous atmospheric measurements: a case study
Abstract. The adoption of low-cost sensors (LCS) is growing steadily due to their affordability, ease of use, and broad applicability. However, concerns remain regarding their reliability, prompting continued investigations into their performance and proper handling of measurements.
This study uses a three week field campaign in a urban area in central Italy carried out during the winter holiday season. Atmospheric physical and chemical parameters, temperature, relative humidity, pressure, concentration of carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), ozone in the form of O3 and OX and particulate matter PM2.5 and PM10, have been measured by three different commercial LCS platform (Vaisala AQT, AirSensEUR and Libelium Smart Environment PRO) in their factory primary calibration, to assess their initial performance. The LCS have been placed in a site close to two meteorological stations hosting standard certified reference instruments, which have been used for the intercomparison process. Additionally a 2B Ozone Monitor, EPA-certified Federal Equivalent Method, has been mounted next to the LCS, to add ozone to the evaluated variables. Due to the absence of a CO reference dataset, only a comparison between LCS has been performed to asses consistency for this measurement.
Meteorological measurements showed high correlation (R ∼ 0.9) across all LCS with the reference data, except for a discrepancy in temperature and relative humidity for AirSensEUR. The concentrations of NO and NO2 exhibited a good correlation (R ≥ 0.75) with reference instrument, although some discrepancies and deviations from the ideal linear relationship were observed. Differently ozone comparison had a good similarity only for Vaisala AQT (R ∼ 0.8), while for the remaining two the differences are noticeable (R ∼ 0.5). CO time series across the three low-cost sensors are almost the same. Finally, both PM values, available from the reference only as daily averages, showed a reasonable level of agreement with the reference instrument for AirSensEUR, albeit with greater variability.
The LCS data acquired in the atmosphere was also analysed in relation to nearby pollution sources. Workday versus holiday daily comparison and wind pollutant correlation have been executed with the aim to evaluate the ability of these LCS to recognize daily patterns and attribute pollutant sources.
Results show the potential information-driven applications of these commercial low-cost sensors, detecting emission patterns during rush hours and holidays.
Competing interests: At least one of the (co-)authors is a member of the editorial board of Atmospheric Measurement Techniques.
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