A SRF2-BASED OXYGEN SENSOR OPERATIVE AT LOW-TEMPERATURE

Potentiometric disk type oxygen sensors monitoring in low temperatures (200-500 degrees C) were fabricated using SrF2 and their sensing char acteristics were investigated. The disk type oxygen sensors consist of a reference electrode: Air (O-2)/Pt, a solid electrolyte SrF2 and a s ensing Pt electrode. The correlation between the electromotive force(E MF) and oxygen partial pressure at various temperatures between 200 an d 500 degrees C was obtained. The experimental results were found to f ollow the Nernst equation in the test range of 0.1-100% oxygen partial pressure. The sensor element of the disk type showed an EMF change of 60 mV for an oxygen concentration change of 1-10% at a device tempera ture of 300 degrees C. The sensor with Ni/NiO reference electrode show ed an EMF change of 55 mV change for an oxygen concentration change of 0.1-10% at the same temperature. (C) 1998 Elsevier Science S.A. All r ights reserved.