AG-BETA''-ALUMINA SOLID-ELECTROLYTE SO(X) SENSOR WITH METAL SILVER ASA SOLID REFERENCE ELECTRODE()

Polycrystalline Ag+-beta''-Alumina tubes were prepared from Na+-beta'' -Alumina by ion exchange and characterized by XRD, DTA, TGA, SEM and E DX analyses. Applying tubular Ag+-beta''-Alumina as solid electrolyte, metallic Ag as a solid reference electrode and porous Pt as a working electrode, fully solid galvanic cells were constructed as electrochem ical SO(x) sensors Pt, Ag\Ag+-beta''-Alumina\porous Pt, SO2-SO3-O2, Pt . The sensors were tested in a small commercial-type testing system. T he Nernst emf response of the sensor to the SO2 Partial pressure is fa irly consistent with the theoretical prediction in the working tempera ture range of 500 - 700-degrees-C and the SO2 Concentration range of 1 0 to 1000 ppm. The response time is usually about 5 - 10 min. The expe rimental results indicate the potential of this SO2 sensor in practica l use.