ZEOLITES AS SENSITIVE MATERIALS FOR DIELECTRIC GAS SENSORS

Modern sensors are becoming increasingly important as key components in the progressive automation of industrial processes. Particular interest is attached to sensors that can be miniaturized, such as the capacitive gas sensors for hydrocarbons described in this paper. Coating planar interdigital capacitors with highly selective zeolites can improve the performance, particularly the selectivity, of gas sensors. The response 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 on the sensor characteristics has been studied by means of impedance spectroscopy. The design of the sensor and the way in which it functions are discussed.