... Buccolieri, and D. Manno, , Sensors and Actuators B, vol. 145, p. 794, 20 10. [37] P G. Su and T T. Pan, Mater. Chem. and Phys., vol. 125 , p. 351, 20 11. Monitoring, Control and Effects of Air Pollution ... [RHCHO/R air ] 50 ppm 40 ppm 30 ppm 20 ppm 10 ppm Fig. 8. HCHO Gas-sensing properties of La0.8Sr0 .2 FeO3 [17]. 100 150 20 0 25 0 300 3501.01 .2 1.41.61.8 2. 0 2. 2 2. 4 2. 6 2. 83.0 ... (ECOTECH, 20 07). Fig. 4. A pneumatic diagram for EC9 820 CO2 analyzer (ECOTECH, 20 07). Monitoring, Control and Effects of Air Pollution 60 oxides, sulfur dioxide, and suspended particles....