Gas sensors have gained a lot of attention in the last decades due to their wide role ranging from industrial applications to atmospheric monitoring . The main sources of SO2 include burning from fossil fuels in power stations, oil refineries, motor vehicles and domestic boilers. In comparison to gas detection techniques like optical, chemical fluorescence or infrared absorption spectrum sensing is the most popular technique for toxic gas monitoring, these are not suitable for in-situ SO2 gas monitoring because this equipment is too expensive and too large to install at every emission site and also it need some pretreatment of the gas. In this study, we have developed a solid electrolyte type SO2 gas sensor by thick film screen printing method. The satisfactory results obtained with high sensitivity present a promising path to the development of high temperature sensors that could be used in industrial production.

The stability brought by the all-solid-state design also makes it unnecessary to use high-cost special materials in the packaging of the sensing element, which increases the production cost. The expected cost of the sensor developed in this project can be reduced to less than $100, and it will have a considerable competitive advantage in price.

The commonly SO2 gas sensors using liquid electrolytes although can present good response characteristics but it has problems of maintenance such as leakage and evaporation of electrolyte and corrosion. This prompted us to investigate a new type of solid-state gas sensor which can work at high temperature and high pollution such as power stations, oil refineries, other large industrial plants.