Abstract
The emf measurement of two types of solid oxide galvanic cells have been carried out to measure the oxygen partial pressure in argon and nitrogen. The cells are
Cell (A) Pt, pO2′(gas)/ZrO2(CaO)/pO2′′(gas), Pt
Cell (B) Pt, Ni-NiO/ZrO2(CaO)/O(in Ag), pO2′′(gas), Fe.
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oindentCell (A) was used to measure the oxygen partial pressure directly. Cell (B) was used for indirect measurement by determinig the oxygen activity in liquid silver in equilibrium with oxygen in argon blown into the melt.
The obtained results are as follows:
(1) In the case of cell (A), the emf was increased with increasing flow rate of argon, but constant emf values were obtained by keeping the flow rate beyond a critical value i, e, “Vmin”.
(2) When the flow rate was beyond the Vmin for cell (A), the measured values of oxygen partial pressure showed a good accordance with that by cell (A).
(3) Ullmann’s equation gave an explanation to the relation between the gas permeability of solid electrolyte and the dependence of emf on the gas flow rate in cell (A).
