Reference Tables for Platinum-40% Rhodium/Platinum-20% Rhodium Thermocouples

Reference tables covering the temperature range 0–1880°C have been established for platinum-40% rhodium/platinum-20% rhodium thermocouples. They are based on calibrations in air of ten thermocouples from four wire lots. These calibrations included freezing point determinations of zinc, antimony, silver, and gold; melting point determinations of palladium and platinum by the wire method; comparisons with standard platinum-10% rhodium/platinum and platinum-20% rhodium/platinum-5% rhodium thermocouples from 0 to 1750°C; and intercomparisons of the test thermocouples from 0 to 1850°C. The accuracy and stability to be expected from this thermocouple combination is discussed. More detailed tables than those presented here are available as APH Report No. 1292.