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

The paper describes the construction of an SAW gas sensor which is essentially a sorption type sensor but also has a number of properties of thermometric type SAW sensors. In other words, a sensor is proposed which is capable of detecting not only the vapour of volatile substances but also gases from their thermal properties. The high thermal stability and reaction rate of the sensor are maintained in contrast to the usual SAW thermometric type sensors. A variant of SAW sensor design using an LiNbO3 delay line is described, and some results are given of an experimental study using the example of the detection of propane-butane.