Abstract Number: 794 Working Group: Instrumentation and Methods
Abstract A low-cost PM monitor based on the popular PPD42 sensor was developed was developed and deployed in two Chinese cities, Nanjing in the Yangtze River Delta and Chengdu in the Sichuan Basin, from December 2015 to August 2017, side by side with BAM-1020 PM2.5 monitors to determine their capability in measuring PM2.5 concentrations under concentrations relevant to pollution levels in China. A novel algorithm based on artificial neural network (ANN) was developed to better account for the influence of relative humidity and temperature to improve the correlation between low-cost monitor raw readings with the reported PM2.5 concentrations by the BAM-1020. At the Nanjing site (on campus of Nanjing University of Information Science and Technology, or NUIST), multiple instruments were developed to test the reproducibility of the sensor readings. The low-cost monitors were shown to be able to reproduce the observed PM2.5 concentrations within ±20%, with better performance at higher concentrations. Reproducibility of the sensors were shown to be acceptable when the sensors were of the same age. However, the response of the sensors appears to change slowly, due to either decay of the sensor or accumulation of dust within the sensor so that sensors of different ages lead to different raw readings.