Type T thermocouple
Cu / Cu-Ni · -270 … 400 °C · IEC 60584-1
At a glance
- Conductors (+ / −)
- Cu / Cu-Ni
- Range of the reference function
- -270 … 400 °C
- Sensitivity at 100 °C
- 46.78 µV/°C
- Class 1 tolerance
- ±0.5 °C or ±0.004 × |t|, whichever is larger, -40 to 350 °C
- Class 2 tolerance
- ±1 °C or ±0.0075 × |t|, whichever is larger, -40 to 350 °C
Wire colours
| Positive | Negative | Sheath / Jacket | |
|---|---|---|---|
| IEC 60584-3 (international) | brown | white | brown |
| ASTM E230 / ANSI (USA), extension wire | blue | red | blue |
Colours identify the type, not the quality of the cable. Older national codes (e.g. BS 1843, DIN 43714, JIS) used other colours; check before reusing existing cable.
EMF at common temperatures (0 °C reference)
| Temperature (°C) | EMF (mV) | Sensitivity (µV/°C) |
|---|---|---|
| -200 | -5.603 | 15.74 |
| -100 | -3.379 | 28.39 |
| 0 | 0.000 | 38.75 |
| 50 | 2.036 | 42.82 |
| 100 | 4.279 | 46.78 |
| 200 | 9.288 | 53.15 |
| 300 | 14.862 | 58.09 |
| 400 | 20.872 | 61.80 |
Typical use and limits
Copper against constantan: the most accurate base-metal type near ambient and below zero, used in food, pharmaceutical, laboratory and cryogenic work. The copper leg oxidises above about 370 °C, which sets the practical upper limit. Copper conducts heat well, so watch for stem conduction errors in short immersion lengths.
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