CEST2025

Currently, low-cost air quality sensors (LCS) face challenges in accuracy and reliability. Despite these limitations, they remain useful for broader air quality monitoring as technology improves. In the frame of TREEADS project a novel LCS prototype system for both indoor and outdoor carbon monoxide (CO) and particulate matter (PM) monitoring has been developed, validated and evaluated in controlled environment. The current work describes the design and construction of LCS to detect and measure PM & CO. The study also includes the validation of 6 LCS devices by comparing their performance with reference-grade instruments, using advanced statistical analysis to evaluate accuracy and reliability under to different environmental conditions. A very strong correlation (r>0.9, p<0.01?) has been exhibited among the measurements by the six LCS, for all the particle fractions and both indoor microenvironments, as revealed by Pearson test. Regarding the correlation between LCS and the reference instrument, a very strong correlation was observed for smaller fraction (PM1, r>0.9), which slightly decreased for bigger PM fractions (PM2.5, R=0.9; PM4, R=0.8)