Tungsten-Rhenium thermocouples were developed to meet the requirements for measuring ultra-high temperatures in the 2760°C (5000°F) range. OMEGA® makes available three widely used Tungsten- Rhenium thermocouple calibrations.
Tungsten versus Tungsten-26% Rhenium Tungsten-5% Rhenium versus Tungsten-26% Rhenium Tungsten-3% Rhenium versusTungsten-25% Rhenium.
Because of the inherent brittleness of unalloyed Tungsten, the Tungsten versus Tungsten-26% Rhenium thermocouples are more difficult to handle than the Tungsten-5% Rhenium versus Tungsten-26% Rhenium combination. The average EMF of the W-3% Re/W-25% Re is slightly less than that of W/W-26% Re and slightly more than that of W-5% Re/W-26% Re. The ductility of W-3% Re is about equal to that of W-5%Re, but superior to that of unalloyed Tungsten. All three thermocouple calibrations can be used to 2760°C 5000°F) in hydrogen or inert gas atmospheres and in a vacuum. They undergo rapid deterioration under oxidizing conditions and should not be used in air or atmospheres containing oxygen. OMEGA® Tungsten-Rhenium thermocouples are supplied in 300 mm (12") lengths (600 mm [24"] loop). Longer lead lengths are available, Consult Sales.