Detection of gases and vapours concentration from resonance curve of interdigital system

Abstract

Interdigital structure with thin film sensitive organic layer is the base of many sensors for gases and vapours detection. This structure with sensitive layer has capacitive character where the influence of gas and vapour causes the change of its capacitance and dissipation factor. Resonance circuit, created by interdigital structure and an inductor, is then suitable for gas and vapour concentration detection. This article describes methods of relative humidity detection from the resonance circuit curve and presents many experimental results as well.