Terminology » Measurements » Thermocouple Types: J, K, T, N, E, B, R, S - Differences Explained

Thermocouple Types: J, K, T, N, E, B, R, S - Differences Explained

thermocouple temperature sensor measurement sensor instrumentation

This article highlights the key differences between various thermocouple types, including Type J, Type K, Type T, Type N, Type E, Type B, Type R, and Type S.

Here’s a comparison table summarizing the key characteristics:

Thermocouple TypeMaterials UsedTemperature RangeAccuracy
Type JIron/ ConstantanThermocouple grade wire, -346 to 1,400F (-210 to 760C) Extension wire, 32 to 392F (0 to 200C)Standard: +/- 2.2C or +/- .75% Special Limits of Error: +/- 1.1C or 0.4%
Type KNickel-Chromium / Nickel-AlumelThermocouple grade wire, -454 to 2300F (-270 to 1260C) Extension wire, 32 to 392F (0 to 200C)Standard: +/- 2.2C or +/- .75% Special Limits of Error: +/- 1.1C or 0.4%
Type TCopper/ ConstantanThermocouple grade wire, -454 to 700F (-270 to 370C) Extension wire, 32 to 392F (0 to 200C)Standard: +/- 1.0C or +/- .75% Special Limits of Error: +/- 0.5C or 0.4%
Type NNicrosil / NisilThermocouple grade wire, -454 to 2300F (-270 to 392C) Extension wire, 32 to 392F (0 to 200C)Standard: +/- 2.2C or +/- .75% Special Limits of Error: +/- 1.1C or 0.4%
Type ENickel-Chromium/ ConstantanThermocouple grade wire, -454 to 1600F (-270 to 870C) Extension wire, 32 to 392F (0 to 200C)Standard: +/- 1.7C or +/- 0.5% Special Limits of Error: +/- 1.0C or 0.4%
Type BPlatinum Rhodium -30% / Platinum Rhodium -6%Thermocouple grade wire, 32 to 3100F (0 to 1700C) Extension wire, 32 to 212F (0 to 100C)Standard: +/- 0.5% Special Limits of Error: +/- 0.25%
Type RPlatinum Rhodium -13% / PlatinumThermocouple grade wire, -58 to 2700F (-50 to 1480C) Extension wire, 32 to 392F (0 to 200C)Standard: +/- 1.5C or +/- .25% Special Limits of Error: +/- 0.6C or 0.1%
Type SPlatinum Rhodium - 10% / PlatinumThermocouple grade wire, -58 to 2700F (-50 to 1480C) Extension wire, 32 to 392F (0 to 200C)Standard: +/- 1.5C or +/- .25% Special Limits of Error: +/- 0.6C or 0.1%

Here’s a visual representation of thermocouple temperature vs voltage graph:

thermocouple temperature vs voltage graph