Type C — W5Re / W26Re Thermocouple
Tungsten-5% Rhenium / Tungsten-26% Rhenium. CRITICAL: Type C must never be used in oxidizing atmospheres at any temperature. Requires vacuum, hydrogen, or pure inert (Ar/He) atmosphere. Becomes brittle after use above ~1200°C due to recrystallization. Requires Mo or Ta sheath for high-temp vacuum service.
At-a-Glance Specifications
EMF Reference Values — Type C (ASTM E696)
Selected EMF values in millivolts referenced to 0°C. Full tables available on the EMF Tables page.
Key EMF Values
0°C=0.000, 200°C=3.167, 400°C=6.743, 600°C=10.501, 800°C=14.110, 1000°C=17.352, 1500°C=25.005, 2000°C=29.317, 2315°C=31.204 mV
Limits of Error — ASTM E696 / IEC 60584-2
| Class | Range | Limit of Error |
|---|---|---|
| Standard | 0 to +2315°C | ±4.5°C or ±1.0% (whichever greater) |
| Special | 0 to +2315°C | ±2.3°C or ±0.5% (whichever greater) |
All specifications, EMF-temperature tables, and tolerance limits for Type C are defined under ASTM E696. Consult the current edition of this standard for complete reference function coefficients and limits of error across all temperature sub-ranges.