A SO2 gas sensor based upon composite Nasicon/Sr-β-Al2O3 bielectrolyte

A new SO2 gas sensor based upon interfacing two composite solid electrolytes-NASICON containing up to 40 wt.% Na2O·Al2O3·4SiO2 glass and Sr-β-Al2O3 containing 3 mol % Y2O3-ZrO2 with a Na2SO4 electrode and a Pt/O2 reference electrode has been designed and tested. In this design, both the electrodes are exposed to the same test gas thus eliminating the need for a separate reference compartment. The experimental results have shown that the measured emf of the sensor varied linearly as a function of logarithm of partial pressure of SO2 over a concentration range of 1-1000 ppm in the temperature range of 873-1073 K. The emfs were stable and reproducible and the response time was approximately 1 min.