Tools
Thermocouple Tolerance Calculator
Calculate ASTM E230 / IEC 60584-2 limits of error for any thermocouple type at a given temperature. Covers Standard and Special tolerance classes for all nine standardized types.
Limits of Error Calculator
ASTM E230 · ASTM E1751 · ASTM E696 · IEC 60584-2
Select a thermocouple type to see valid temperature range.
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limits of error
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Quick Reference — ASTM Tolerance Summary
| Type | Conductors | Standard Tolerance | Special Tolerance | Standard Range | Standard |
|---|---|---|---|---|---|
| J | Fe / Cu-Ni | ±2.2°C or ±0.75% | ±1.1°C or ±0.4% | 0 to +760°C | ASTM E230 |
| K | Ni-Cr / Ni-Al | ±2.2°C or ±0.75% | ±1.1°C or ±0.4% | 0 to +1260°C | ASTM E230 |
| T | Cu / Cu-Ni | ±1.0°C or ±0.75% | ±0.5°C or ±0.4% | 0 to +370°C | ASTM E230 |
| E | Ni-Cr / Cu-Ni | ±1.7°C or ±0.5% | ±1.0°C or ±0.4% | 0 to +870°C | ASTM E230 |
| N | Ni-Cr-Si / Ni-Si | ±2.2°C or ±0.75% | ±1.1°C or ±0.4% | 0 to +1260°C | ASTM E230 |
| R | Pt-13%Rh / Pt | ±1.5°C or ±0.25% | ±0.6°C or ±0.1% | 0 to +1480°C | ASTM E1751 |
| S | Pt-10%Rh / Pt | ±1.5°C or ±0.25% | ±0.6°C or ±0.1% | 0 to +1480°C | ASTM E1751 |
| B | Pt-30%Rh / Pt-6%Rh | ±0.5% (≥600°C) | ±0.25% (≥600°C) | +600 to +1700°C | ASTM E1751 |
| C | W5Re / W26Re | ±4.4°C or ±1.0% | Not applicable | 0 to +2315°C | ASTM E230 / E696 |
Per ASTM E230, E1751, E696 and IEC 60584-2. Whichever value (°C or %) is greater applies. Sub-zero ranges have separate limits — see Tolerance Tables for complete data.