Abstract: Sulfur and sulfur dioxide are important species in many high temperature systems. The ability to continuously monitor sulfur and sulfur dioxide concentrations in coalgasification environments and exhaust gases is essential for controlling corrosion and air pollution problems.
In this work. four necessary conditions are summarized for develop a successful design of an electrochemical sensor. According to these condition a new sensor using a two-phase electrolyte (alpha-Li₂ SO₄ and (Li₅Ag)₂SO₄ solid solutions) and a Ag/(Ag₂S0₄) reference electrode has been developed. This sensor can measure sulfur dioxide and/or sulfur trioxide concentrations over a wide composition range in oxidizing atmosphere. The potentiometric response is stable and reproducible for long term measurements.