Fall Evaluation and Calibration of Low-Cost Aerosol Sensors

Abstract

This study found that the only low-cost monitor to fit within EPA standards was the AirBeam3 in the month of September. For linear regression, the EPA requires a slope value of 1.0 + 0.35, and a R2 value > 0.70. Clarity and BlueSky both were outside of the EPA standards and inaccurate when compared to the ADR-1500 reference monitor. In September, AirBeam3 reported a slope value of 0.76 and a R2 value of 0.75, fitting within the EPA standards. For the months of October to November AirBeam3’s slope value decreased and ranged from 0.45-0.66 with R2 values ranging from 0.35-0.43. Clarity was outside of the EPA standards for each month with slope values ranging from 0.43-1.31 and R2 values ranging from 0.28-0.52. These large slope values for Clarity were in the months of September and December, with large drops in October and November. BlueSky was outside of the EPA standards as well, with slope values ranging from 0.15-0.36 and R2 values ranging from 0.17-0.70. BlueSky’s R2 value consistently decreased as the experiment continued, hitting its lowest value of 0.17 in December. While these values are widely not withing the EPA standards, Clarity had the best slope values while AirBeam3 had the best R2 values.