Analog Front End Multiplexing for Amperometric Gas Sensors

Advances in modern gas sensors and in smart systems development have made it possible to have new cost effective and accessible air quality monitoring tools. This paper presents a multiplexing of commercially available analog front-end (AFE) for four-electrode amperometric gas sensors. This approach allows for the easy expansion of the number of channels for analogue-to-digital conversion, which is important especially for multi-sensor systems for air quality monitoring. Along with this additional air parameters can be measured and thus accuracy improvement can be achieved by applying corrective algorithms. The proposed sensor interface has been tested in the field with a wireless module and shows accuracy comparable to that of the multi-channel DAQ in laboratory conditions.