Performance evaluation of Plantower’s PMSX003N: Laboratory and field analysis

The PMSX003N, a new type of low-cost Plantower particulate matter sensor (PMS), was evaluated in the laboratory and the field for its efficiency in measuring particulate matter (PM) concentrations. The laboratory evaluation included size binning performance using monodisperse dioctyl sebacate particles generated through a flow focusing monodisperse aerosol generator, with target diameters in bins: 0.3–0.5 µm, 0.5−1 µm, 1–2.5 µm, 2.5–5 µm, and 5–10 µm. The field evaluation involved the collocation of low-cost sensors, including three PMSX003N, three PMS5003Ts, and three OPC-N3s, with federal equivalent methods (FEM) at a Utah Department of Environmental Quality monitoring station for five months between Dec 2025 – Apr 2026. This monitoring station experienced diverse meteorological events, i.e., dust events, winter inversions, freezing fog, mist, snow, and rain, during these five months. Laboratory testing showed that the PMSX003N preferentially assigns particles >1 µm in diameter to the 2.5–5 µm size bin. The field performance strongly depended on meteorological and relative humidity conditions. The PMSX003N produced PM2.5 and PM10 estimates more comparable to FEM measurements than the PMS5003T estimates during dust events (slope between 1.85–1.91 and R2 > 0.7 for PMSX003N PM2.5 vs. slope of 0.15 and R2 < 0.37 for PMS5003T PM2.5 and slope between 0.91–1.07 and R2 ∼0.6 for PMSX003N PM10 vs. a slope of ∼0.02 and R2∼0.63 for PMS5003T PM10), but substantially overestimated PM2.5 and PM10 concentrations during high-humidity conditions (i.e., freezing fog, mist, snow, and rain). These findings highlight the need for humidity-dependent correction strategies.