CALCIUM BETA''-ALUMINA AND NASICON ELECTROLYTES IN GALVANIC CELLS WITH SOLID REFERENCE ELECTRODES FOR DETECTION OF SULFUR-OXIDES IN GASES

Calcium-beta"-alumina and Nasicon were applied as solid electrolytes for SO(x) (x = 2 or 3) gas detection. The following two galvanic cells with solid reference electrodes were assembled Pt\O2, CaO parallel-to Ca-beta"-Al2O3 parallel-to CaSO4\SO3, SO2, O2\Pt Pt\O2, Na2O parallel-to Nasicon parallel-to Na2SO4\SO3, SO2, O2\Pt Calcium and sodium sulphates were used as auxiliary electrolytes to provide protection of beta"-Al2O3 or Nasicon electrolytes from chemical reaction with SO2. The e.m.f. was measured in the temperature range 850-1070 K for five various test gases. The measured e.m.f.s had values a little lower than the calculated ones. The results show clearly that both the cells can act as SO(x) electrochemical sensors for temperatures not exceeding 1070 K.