Tempsens manufacture noble metal thermocouples (also called rare metal thermocouples) for many types of industries. The most common types are R, S & B rare metal thermocouple assemblies.
Noble metal thermocouples are used for measurement of higher temperatures.
Names of Materials
Platinum 13% Rhodium (+)
0 to 1600°C
Platinum 10% Rhodium (+)
0 to 1600°C
Platinum30% Rhodium (+)
Platinum 6% Rhodium (-)
600 to 1600°C
Type R thermocouple
This thermocouple is made from Platinum which is the negative leg and much softer and Platinum 13% Rhodium which is the stiffer positive leg. It is suitable for use in oxidising or inert atmospheres and may be used under reducing conditions or in a vacuum provided care is taken to ensure the refractory materials are free from siliceous materials. Pure recrystallised alumina is recommended. This thermocouple is suitable for continuous use up to 1400 C and for intermittent use up to 1650 C
Type S thermocouple
This thermocouple defines the international practical temperature scale between Antimony point (630.73 C ) and the gold point (1064.43 C). This thermocouple is made from Platinum which is the negative leg and much softer and Platinum 10% Rhodium which is the stiffer positive leg, and has the same operating requirements as type R. Again This thermocouple is suitable for continuous use up to 1400 C and for intermittent use up to 1650 C..
Type B thermocouple
This combination platinum thermocouple is made from Platinum-30% Rhodium and Platinum -6% Rhodium. When they are compared to pure platinum thermocouples they suffer less from the effects of 'Rhodium migration' and may be used at somewhat higher temperatures, continuous operating 1500 C and up to 1800 C intermittently.
Type S thermocouples are regularly used in the electric arc furnace process to accurately measure the steel's temperature before tapping. The cooling curve of a small steel sample can be analyzed and used to estimate the carbon content of molten steel.