Type R and S Thermocouple

Type R and S Thermocouples are made from Platinum and Rhodium thermocouple alloys and designed to be extremely stable with an ASTM recommend temperature range up to 2,700°F (1480°C). Type R and S are resistant to oxidation in air although reducing atmospheres can be especially damaging.

• Overall Temperature range is -58 below zero to 2,700°F (-50 to1480°C) and can be used intermittently up to 1600°C. This wide temperature range and high level of stability provides excellent overall application opportunities. 
  • Most times R and S thermocouples are utilized at temperatures of 1800°F (1000°C) and higher due the thermocouple alloy having low milivolt output per degree at lower temperatures.
  • This low output along with the high materials cost reduces the opportunity to use this thermocouple in general purpose applications
  • Type R and S is not recommended in reducing atmospheres, unless the thermocouple alloys are protected with a gas-tight ceramic tube and a secondary tube of alumina, silicon carbide, or a metal outer tube
• Type R has 3% more Rhodium and it offers improved stability and a slightly higher temperature range than Type S
  • Type R can deliver 15 percent more millivolt output than Type S.
  • Type R compostion is a positive wire Platinum with 13% Rhodium, the negative wire is 99.99% Platinum
  • Type S content is a positive wire Platinum with 10% Rhodium the negative wire is 99.99% Platinum
• Connector pins and Extension cables are made with a specially designed compensating alloy to reduce cost although at the same time ensuring the accurate transfer of the thermocouple signal