Control and monitoring of oxygen content in molten metals. Application to lead and lead-bismuth melts

The sources of error in potentiometric measurements of the oxygen activity in molten metals and the methods proposed to reduce these measurement errors are described. Specific constraints related to low temperature measurements are emphasized. Two set-ups for control of the oxygen activity in molten lead and lead-bismuth were developed. They involve zirconia-based cells, i.e., an oxygen pump and an oxygen probe. The performance of the set-ups was characterized. Attempts to reduce the working temperature (T < 450 degreesC) are discussed.