ZEOLITES AS SENSITIVE MATERIALS FOR DIELECTRIC GAS SENSORS

Modern sensors are becoming increasingly important as key components i n the progressive automation of industrial processes. Particular inter est is attached to sensors that can be miniaturized, such as the capac itive gas sensors for hydrocarbons described in this paper. Coating pl anar interdigital capacitors with highly selective zeolites can improv e the performance, particularly the selectivity, of gas sensors. The r esponse of the sensor is measured by the change in the capacitance of the interdigital capacitors at a frequency of 1 kHz. The influence of the capacitor structure and of differently modified molecular sieves o n the sensor characteristics has been studied by means of impedance sp ectroscopy. The design of the sensor and the way in which it functions are discussed.