Type:

Types S, R and B
R-type and S-type temperature range 1398 ~ 1482°C (2550 ~ 2700°F)
Type B is suitable for continuous use at temperatures up to 1704°C (3100°F)
To effectively prevent oxidation and corrosion at high temperatures, OMEGA offers high-quality uninsulated thermometer wires that can be applied to 3 types of “precious metal” thermocouples:
Type S: Platinum (-) and Platinum 10% Rhodium (+)
Type R: Platinum (-) and Platinum 13% Rhodium (+)
Type B: Platinum 6% Rhodium (-) and Platinum 30% Rhodium (+)
Types R and S are recommended for continuous use in oxidizing or inert atmospheres at temperatures up to 1398°C (2550°F), or short-term exposure to high temperatures up to 1482°C (2700°F). Type B is suitable for continuous use in oxidizing or inert atmospheres up to 1704°C (3100°F). When working close to the maximum temperature, it is recommended to use a larger wire diameter.
All 3 types of thermocouples can be used in a vacuum environment for short periods of time. Type B provides the best stability when applied in a vacuum environment. All 3 models are not suitable for use in reducing gases or environments containing metallic or non-metallic vapors unless a non-metallic protective sleeve is used. Never insert thermocouples directly into metal protective sleeves.