Investigation of High-Temperature Platinum Resistance Thermometers at Temperatures up to 962 Degress Celsius, and, in so cases, 1064 degrees Celsius

摘要

The stability of high temperature standard platinum resistance thermometers, having nominal resistances of 0.25 to 2.5 ohms, and their use in the realization of the International Temperature Scale of 1990 over the range of 0 degree C to 961 degrees C were investigated. Special procedures were employed for their use above 500 degrees C. These techniques involved annealing and protection against contamination. A sodium heat-pipe furnace was used to realize the freezing points of aluminum, silver, and gold.