The article describes the concept of the digital gas sensors for toxic and flammable gases used in portable gas analyzers and stationary systems for dangerous objects monitoring. The results of the development of the low-power digital gas sensor for determining the concentration of carbon monoxide are described. The structure of the analog sensitive element, as well as its sensitivity to various gases and ambient temperature, is considered. A structural and schematic solution of a digital gas sensor using operational amplifiers and a miniature microcontroller is presented. The algorithm of firmware of the microcontroller is considered, as well as the calibration process.

Keywords: Digital gas sensor, toxic gas, gas converter, carbon monoxide, gas analyzer, monitoring system, calibration process, gas generator