MULTISENSOR MICROSYSTEM FOR CONTAMINANTS IN AIR

A novel multisensor microsystem for gas sensing, containing 39 metal o xide detectors, 2 temperature sensors and 4 heaters on an area of 8 x 9 mm(2), is described including design, fabrication process and exampl e application to a mixture of organic gases in air. Recognition of dif ferent air contaminants is achieved by pattern recognition of the sign als obtained, using temperature gradients and inhomogeneous ceramic me mbranes to tune the selectivity of the sensor elements. A gas sensor c hip equipped with tin dioxide exhibits detection limits well below 1 p pm for most organic vapors. The overall analysis time, including measu rement of all signals and pattern evaluation, is about 100 s.