The placement of reference electrodes in solid galvanic cells was considered. The common flat arrangement with a reference electrode side by side on an extension of the solid electrolyte (SE) was experimentally convenient but poses difficulties in the evaluation of the results. Common interpretation of the measurement introduce an error into the impedances determined. The error may be significant. A calibration method was presented that allows to relate the true impedance to measured signals. It was also shown that in the special case where the extension in the SE could be made thinner than the SE, the placement of the reference electrode side by side introduces only a negligible error. In the case when the current carrying electrodes could be made of equal size, only misaligned, the error could be corrected, to first order, by the use of two reference electrodes and an averaging procedure.

Reference Electrodes for Thin-Film Solid-State Ionic Devices. J.Rutman, I.Riess: Solid State Ionics, 2008, 179[1-6], 108-12