Instrumentation of YSZ oxygen sensor calibration in liquid lead-bismuth eutectic

Liquid lead-bismuth eutectic (LBE), a good candidate for the coolant in the subcritical transmutation blanket, is known to be very corrosive to the stainless steel that transports it. Such a corrosion problem can be prevented by producing and maintaining a protective oxide layer on the exposed surface of the stainless steel. Proper formation of the oxide layer critically depends on the accurate measurement and control of the oxygen concentration in liquid LBE. An oxygen sensor calibration/measurement apparatus has been designed and built to deliberately calibrate an yttria stabilized zirconia (YSZ) oxygen sensor. A detailed description of this system with its main components and their functions is presented. Calibration curves of voltage vs. temperature, ranging from 350°C to 550°C, under various oxygen concentrations in liquid LBE have been obtained for the YSZ oxygen sensors, and are presented and analyzed. The characteristics of this YSZ oxygen sensor are analysed and discussed.