A high purity ceramic oxygen generator incorporating a module utilizing a plurality of tubular ceramic membrane elements and configured to operate in: (i) a pressurizing mode to separate oxygen from an oxygen containing feed stream when an electric potential difference is applied to induce oxygen ion transport in an electrolyte thereof; and (ii) an idle mode when the electric potential difference is removed. The ceramic oxygen generator further includes one or more manifolds as well as one or more automatic purge valves located upstream of the oxygen receiving tank. The purge valve is opened for a pre-set duration upon initiation of the pressurization mode to purge any nitrogen or other contaminating gas that diffuses into the ceramic oxygen generator during idle mode thereby ensuring the desired purity level of oxygen is received by the oxygen receiving tank.