... Manno, , Sensors and Actuators B, vol. 145, p. 794, 2010. [37] P G. Su and T T. Pan, Mater. Chem. and Phys., vol. 125, p. 351, 2 011. Monitoring, Control and Effects of Air Pollution 66 ... HCHO Gas-sensing properties of LaFeO3 [17]. Monitoring, Control and Effects of Air Pollution 68 Fig. 14. Time-series plots of CO2 measurements (in the units of ppm) at two sites (blue ... analyzer (ECOTECH, 2007). Monitoring, Control and Effects of Air Pollution 60 oxides, sulfur dioxide, and suspended particles. Since detailed measurements of carbon dioxides close to...