Thermocouple Voltage To Temperature Calculator

Work out thermocouple voltage to temperature instantly with clear inputs, formula shown and shareable results.

About Thermocouple Voltage To Temperature Calculator

A thermocouple measures the difference between its measuring and reference junctions, so the cold junction temperature must be added back. Using the average Seebeck coefficient (about 41 microvolts per degree for type K) gives a linear approximation adequate over a moderate span.

Formula

Thermocouple

T_hot = V / Seebeck coefficient + T_cold junction

Worked example

With the default values below, Thermocouple Voltage To Temperature Calculator returns Measured temperature of 124.90. Change any input above and every figure here is recalculated in your browser.

Inputs used

Thermocouple output: 4.096 mV
Thermocouple typeone of Type K (chromel-alumel), Type J (iron-constantan), Type T (copper-constantan), Type E (chromel-constantan): Type K (chromel-alumel)
Cold junction temperature: 25 °C

Results

Measured temperature: 124.90 °C
Seebeck coefficient: 41.00 µV/°C
Temperature without cold junction compensation: 99.90 °C
Cold junction contribution: 25.00 °C

Step by step

1Values used
2Thermocouple
3Measured temperature= 124.90 °C
4Seebeck coefficient= 41.00 µV/°C
5Temperature without cold junction compensation= 99.90 °C
6Cold junction contribution= 25.00 °C

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why is cold junction compensation essential?

Without it the reading is only the temperature difference. A 25 degree instrument terminal block produces a 25 degree error.

How accurate is the linear approximation?

Within a degree or two over a few hundred degrees near the middle of the range. Wide-span or high-accuracy work needs the standard polynomial from IEC 60584.