High temperature thermocouples are fully or semi assembled sensors for temperature measurements starting around 1000°C and up to 2200°C. Due to the insulation and exotic sheath materials these thermocouples can be used in extreme environments where base metal thermocouples are failing.
High temperature thermocouples are often used in extreme or hazardous environments. Examples are vacuum, inert, oxidizing and reducing atmospheres.
For example, our thermocouples are used in vacuum furnaces or ovens up to 2200°C. In that case, a type C or D thermocouple can be used with a Tantalum sheath. This sheath material has recommended maximum temperature of 2200°C and is allowed in inert or vacuum environments.
For High temperature thermocouples we offer Inconel 600, Platina/Rhodium but also the more exotic sheaths like Molybdenum, Tantalum, Niobioum 1% Zirc or coated Molybdenum. These sheath materials are very suitable for challenging environments and high temperatures.
Each sheath material had its own characteristics and best use environments. Please consult this our overview.
| Sheath type | Symbol | Recommended max. temperature | Melting temperature | Allowable environment | Standard sheath diameter in mm | Minimum bend radius* |
| Inconel 600 | B | 1175°C | 1345°C | Inert, vacuum, oxidizing | 1, 1.6, 3.2, 4.8, 6.4 | 5 x diameter |
| Pt10%Rh | AH | 1550°C | 1850°C | Inert, oxidizing | 1, 1.5, 1.6, 2, 3, 3.2 | 5 x diameter |
| Pt20%Rh | AW | 1550°C | 1850°C | Inert, oxidizing | 1, 1.5, 1.6, 2, 3, 3.2 | 5 x diameter |
| Tantalum | N | 2200°C | 2995°C | Inert, vacuum, oxidizing | 1, 1.6, 3.2 | 10 x diameter |
| Molybdenum | O | 2000°C | 2620°C | Inert, vacuum, reducing | 1.6, 3.2, 4.8, 6.4 | Not bendable |
| Niobioum 1% Zirc | OCR | 2000°C | 2495°C | Inert, oxidizing | 1.6, 3.2 | 10 x diameter |
| Coated Molybdenum | AV | 1600°C | 2200°C | Inert, vacuum | 3.2, 6.4 | Not bendable |
