Extensive evaluation and classification of low‐cost dust sensors in laboratory using a newly developed test method

An extensive evaluation of low‐cost dust sensors was performed using an exponentially decaying particle concentration. A total of 264 sensors including 27 sensors with light‐emitting diodes (LEDs) and 237 sensors with laser lighting sources were tested. Those tested sensors were classified into 4 groups based on the deviation from the reference data obtained by a reference instrument. The response linearities of all the tested samples for PM(1), PM(2.5), and PM(10) were in excellent agreement with the reference instrument, except a few samples. For the measurements of PM(1) and PM(2.5), the lighting source, that is, LED or laser, did not show any significant difference in overall sensor performance. However, LED‐based sensors did not perform well for PM(10) measurements. The 32, 24, and 16% of all the tested sensors for PM(1), PM(2.5), and PM(10) measurement, respectively, are in the category of Class 1 (reference instrument reading ± 20%) requirement. The performance of the low‐cost dust sensors for PM(10) measurement was relatively less satisfactory.