Thermocouple Type R: Types R thermocouples, (Platinum vs. 13% Rhodium/Platinum), are usable up to 1480°C (2,700°F). They are extremely stable but reducing atmospheres are particularly damaging. Type R thermocouples cover similar applications as Type S, but offer improved stability and a marginal increase in range. Consequently, Type R tends to be used in preference to Type S.