ABSTRACT
The influence of the gaseous phase over the ceramics properties is of special interest, because it is this influence that lies at the basis of the operating principle of the ceramic sensors for gases and humidity. The response of modern ceramic sensors to an external effect is mainly an electric one—the sensor resistance or the electric current flowing through it changes. Sensor ceramics involves mostly oxide ceramics, which is why the influence of oxygen on the bulk properties of the grains is of importance. The difference is determined by the specific structure of the ceramic materials —their chaotically orientated ceramic grains and the presence of glass and pores. The classification of ceramic materials can be done according to various parameters: chemical composition, phase composition and physical properties. According to the chemical composition of the monocrystal phase ceramics can be oxide or nonoxide.
