Increasing environmental pollution has led to a growing demand for highly sensitive, cheap, user- friendly devices to monitor air pollutants to protect the health of human beings. Surface Acoustic Wave (SAW) based sensors can be produced relatively inexpensively, have low power consumption and are capable of sensing low analyte gas concentrations. They can be easily interfaced with electronics, making them portable devices for multi- spot outdoor measurements. Since 1979 they have been successfully utilised for gas sensing applications and today are used in a wide range of sensor...