Fig. 1From: Preliminary monitoring of concentration of particulate matter (PM2.5) in seven townships of Yangon City, MyanmarPocket PM2.5 Sensor. a Principle of Pocket PM2.5 Sensor Module, LED, light-emitting diode; PD photodiode; USB, Universal Serial Bus. b Pocket PM2.5 Sensor connected to a smart phone with android system. c Color variations for different levels of PM2.5 concentration. (Adapted from Ishigaki et al. 2017, with permission from Yang Ishigaki)Back to article page