Calibration of YSZ sensor for the measurement of oxygen concentration in Lbe

Although liquid lead-bismuth eutectic (LBE) is a good candidate for coolant in the sub-critical transmutation blanket, it is known to be corrosive to stainless steel tubes and containers used in nuclear installations. To prevent the long-term corrosion problem by producing and maintaining a protective oxide layer on exposed surface of stainless steel, it is essential to accurately measure and control the oxygen concentration dissolved in LBE. An automobile style voltametric oxygen sensors, with YSZ (Yttria Stabilized Zirconia) as electrolyte and molten bismuth saturated with oxygen as reference was selected. An instrumentation system was designed specifically for calibrating the YSZ sensor and measure oxygen concentration in LBE. An initial setup was built and some preliminary experiments were conducted to calibrate the oxygen sensor. A set of calibration curves of voltage vs. temperature ranging from 300°C to 500°C under various oxygen concentrations in liquid LBE was obtained and presented here. A new improvised setup and instrumentation have also been developed to obtain more accurate results for a wide range of temperature between 300°C to 700°C

Calibration of YSZ Sensors for the Measurement of Oxygen Concentration in Liquid Pb-Bi Eutectic

Although liquid lead-bismuth eutectic (LBE) is a good candidate for coolant in the subcritical transmutation blanket, it is known to be corrosive to stainless steel, the material of the carrying tubes and containers. Such longterm corrosion problem can be prevented by producing and maintaining a protective oxide layer on the exposed surface of stainless steel. For this purpose, it is required to accurately control the concentration of oxygen dissolved in LBE. Currently, YSZ (Yttria Stabilized Zirconia) oxygen sensors, based on an existing automotive oxygen sensor, with molten bismuth saturated with oxygen as the reference, have been selected for oxygen-concentration measurement. The oxygen concentration difference across the solid electrolyte and the resultant oxygen ion conduction inside the electrolyte establishes an electromagnetic force that is used to measure the ppb level concentration of oxygen dissolved in liquid LBE. A set of calibration curves of voltage vs. temperature ranging from 300 0C to 500 0C under various oxygen concentrations in liquid LBE for the YSZ oxygen sensor has been obtained and is presented in this paper. Although the current calibration strategy using the direct injection of hydrogen and oxygen is still inadequate to determine the oxygen concentration in the system, we have found a good candidate for our purpose, which is varying hydrogen to water steam ratio in the system

EMR Adoption: A User Perception Study

Despite promise of significant benefits, inadequate user acceptance has frequently limited the impact of EMR implementations. Using an action research approach, our team is participating in an EMR implementation at Aravind Eye Care System (AECS), one of the largest eye hospitals in the world, to observe its current practices, measure user perceptions of EMR, plan interventions, and assess their impact. Our proximate research objective is to develop interventions based on sound conceptual foundations and empirical validation rather than in an ad hoc manner, to facilitate EMR acceptance by AECS hospital staff. The ensuing goal is to learn from the post intervention findings to develop guidelines for EMR implementations, particularly in a developing country context. In this paper we report on the first phase of this study, and these initial results show how even simple analysis of perception patterns can help to customize and shape intervention plans