Surface acoustic wave gas sensor of the sorption type sensitive to the thermal properties of gases

The basic principles of a new surface acoustic wave (SAW) gas sensor are described. Being essentially a sensor of the sorption type, the proposed device possesses certain features of the thermometric SAW sensors and is not only sensitive to the vapors of volatile substances, but capable of detecting gases by their thermal properties as well. In contrast to the known thermometric SAW sensors, the proposed sensor is characterized by high temperature stability and fast response. A variant of the sensor based on a LiNbO 3 SAW delay line is described and some results of the test for detecting propane-butane mixtures are presented.