Examining the functional range of commercially available lowcost airborne particle sensors and consequences for monitoring of indoor air quality in residences

摘要

Low-cost airborne particle sensors are gaining attention for monitoring human exposureto indoor particulate matter. This study aimed to establish the concentrationsat which these commercially available sensors can be expected to report accurateconcentrations. We exposed five types of commercial integrated devices and threetypes of “bare” low-cost particle sensors to a range of concentrations generated bythree different sources. We propose definitions of upper and lower bounds of functionalrange based on the relationship between a given sensor's output and that ofa reference instrument during a laboratory experiment. Experiments show that thelower bound can range from approximately 3 to 15 μg/m~3. At greater concentrations,sensor output deviates from linearity at approximately 300-3000 μg/m~3. We alsoconducted a simulation campaign to analyze the effect of this limitation on functionalrange on the accuracy of exposure readings given by these devices. We estimate thatthe upper bound results in minimal inaccuracy in exposure quantification, and thelower bound can result in as much as a 50% error in approximately 10% of US homes.