The development of a novel electrochemical sensor for the detection of conc
entration of atmospheric sulfur dioxide in the low-mg/m(3) range is describ
ed, The gas sensor is based on a platinum microelectrode and a porous polym
er film, which is directly connected with the gas-containing atmosphere, Th
e gas sensor is very sensitive, selective, and reproducible for detection o
f SO2, The linear range over 0.10 mg/m(3) to 150 mg/m(3) and the detection
limits is 0.05 mg/m(3).