Thermocouple Tolerances
American Limits of Error ASTM E230-ANSI MC 96.1
| Temperature Range | Tolerances-Reference Junction 0°C (32°F) | |||||
|---|---|---|---|---|---|---|
| Thermocouple Type | °C | °F | Standard Limit of Error | Special Limit of Error | ||
| °C (Whichever is greater) | °F | °C (Whichever is greater) | °F | |||
| T | 0 to 370 | 32 to 700 | +/-1 or +/-0.75% | ² | +/-0.5 or +/-0.4% | ² |
| J | 0 to 760 | 32 to 1400 | +/-2.2 or +/-0.75% | – | +/-1.1 or 0.4% | – |
| E | 0 to 870 | 32 to 1600 | +/-1.7 or +/-0.5% | – | +/-1 or +/-0.4% | – |
| K or N | 0 to 1260 | 32 to 2300 | +/-2.2 or +/-0.75% | – | +/-1.1 or +/-0.4% | – |
| R or S | 0 to 1480 | 32 to 2700 | +/-1.5 or +/-0.25% | – | +/-0.6 or +/-0.1% | – |
| B | 870 to 1700 | 1600 to 3100 | +/-0.5% | – | +/-0.25% | – |
¹Tolerances in this table apply to new essentially homogeneous thermocouple wire, normally in the size range 0.25 to 33 mm in diameter (30 to 8 AWG) and used at temperatures not exceeding the recommended limits of upper temperature limits for protected thermocouples. If used at higher temperatures these tolerances may not apply.
²At a given temperature that is expressed in °C, the tolerance expressed in °F is 1.8 times larger than the tolerance expressed in °C. Note that wherever applicable, percentage-based tolerances must be computed from temperatures that are expressed in °C.
³Material is normally selected to meet tolerances above 0°C. If thermocouples are required to meet tolerances below 0°C, a special material selection step is usually required.