Measure of carbon dioxide using a gas sensor of a semiconductor type based on tin dioxide (SnO2)

To analyse and predict recent and future climate change on a global scale exchange processes of greenhouse gases-primarily carbon dioxide (CO2)-over various ecosystems are of rising interest [1]. Monitoring the chemical composition of the atmosphere, especially CO2, which is considered one of the main greenhouse gases, is a continuous in specialized measuring stations scattered in different places over the planet. The system proposed in this work measures carbon dioxide using a gas sensor of a semiconductor type based on tin dioxide (SnO2) and is mainly a process of understanding the air quality to meet in one hand to a goal of miniaturization, low cost and portability, and it is a portable desktop instrument which measures carbon monoxide concentration in air, within range of 0-1200 ppm and a resolution of 1ppm. The LCD can display outputs concentration immediately in ppm in real time, every one hour, every three hours or every six hours. On the other hand to carry out either punctual measures in different places or to determine the temporal variations of a fixed site the concentration of carbon dioxide. This system offers two options for display: the first on an LCD display and the second via microcomputer via a RS232 link. Considering the importance of temperature, its measurement is therefore incorporated into the measurement entity.