A novel readout technique for capacitive gas sensors

In this communication we propose a novel readout technique for capacitive gas sensors. It uses periodically operated analog switches together with capacitors and operational amplifiers. These components are available in today standard MOS and CMOS VLSI technologies and are, therefore, fully compatible with digital circuits. The technique provides not only sensor interfacing ans signal amplification but it offers posibility to cancel offset and cross-sensitivity as well. At the same time, the long-time DC-drift has been eliminated.