Applicability of GRIMM devices in co-location approach of low-cost sensor PM<subscript>2.5</subscript> evaluation.

Environmental pollution is of concern worldwide, PM2.5 is one of the pollutions of concern because of its harmful effects on health. In Hanoi - Vietnam, PM2.5 monitoring with low-cost sensor (LCS) has been deployed to raise public awareness and warn local people about air pollution. However, data obtained from LCS products has not been evaluated for accuracy, and there is no formal evaluation system for LCS for researchers, sensor users, and environmental agencies. This study was conducted to evaluate the possibility of using the GRIMM EDM 107 devices as a reference for evaluating PM2.5 LCS. The reference equipment to calibrate GRIMM is Beta attenuation monitoring (BAM). Two GRIMM was used (named: GRIMM 03 and GRIMM 07). Two GRIMM was placed next to BAM in 2 periods: from 30 January to February 2021, and from 20 June to 30 June 2021. The high-resolution GRIMM readings can be used to calculate hourly levels of PM2.5 to compare with the BAM hourly readings directly. Data of both two campaigns covered a reasonable wide range of PM2.5. PM2.5, which are determined by BAM, are in the range of 6 – 118.4 µg/m3. Temperature and RH are in the range of 19.3 – 38.5oC, 24 – 98%. The correlation factors of GRIMM 07, GRIMM 03, and BAM are good for both campaigns. The correlation factors of GRIMMs and BAM are high of 0.92 and 0.88 for GRIMM03 and GRIMM07, respectively. GRIMM 03 and GRIMM 07 still had a high correlation factor of 0.93. However, the slope of GRIMM 03 and BAM are more consistent between the 1st, 2nd campaign, as well as for both campaigns. From the obtained results, GRIMM 03 is chosen for using as a reference for LCS evaluation. [ABSTRACT FROM AUTHOR]