Field Pocket Guide

Thermocouple Tables

Eight letter types, ITS-90, reference junction at 0 °C. Convert temperature to millivolts and back with cold-junction compensation, or generate a reference table at any interval. Built straight from the NIST reference functions.

Guided setup

Tell me the type, the direction, your reading, and the cold-junction reference. The wizard runs the exact same ITS-90 math as the form, and it will confirm the reference since 0 °C versus ambient changes the answer.

The wizard only asks questions and runs the calculator. Every number comes from the deterministic engine, not the AI.

Thermocouple type

Convert

Hot junction (°C)

Cold junction / reference (°C)

Meter reads

—mV

E(hot), ref 0 °C

—mV

E(cold junction)

—mV

Reference table · absolute, ref 0 °C

From (°C)

To (°C)

Step (°C)

°C	mV	°C	mV
0	0.000	510	21.071
10	0.397	520	21.497
20	0.798	530	21.924
30	1.203	540	22.350
40	1.612	550	22.776
50	2.023	560	23.203
60	2.436	570	23.629
70	2.851	580	24.055
80	3.267	590	24.480
90	3.682	600	24.905
100	4.096	610	25.330
110	4.509	620	25.755
120	4.920	630	26.179
130	5.328	640	26.602
140	5.735	650	27.025
150	6.138	660	27.447
160	6.540	670	27.869
170	6.941	680	28.289
180	7.340	690	28.710
190	7.739	700	29.129
200	8.138	710	29.548
210	8.539	720	29.965
220	8.940	730	30.382
230	9.343	740	30.798
240	9.747	750	31.213
250	10.153	760	31.628
260	10.561	770	32.041
270	10.971	780	32.453
280	11.382	790	32.865
290	11.795	800	33.275
300	12.209	810	33.685
310	12.624	820	34.093
320	13.040	830	34.501
330	13.457	840	34.908
340	13.874	850	35.313
350	14.293	860	35.718
360	14.713	870	36.121
370	15.133	880	36.524
380	15.554	890	36.925
390	15.975	900	37.326
400	16.397	910	37.725
410	16.820	920	38.124
420	17.243	930	38.522
430	17.667	940	38.918
440	18.091	950	39.314
450	18.516	960	39.708
460	18.941	970	40.101
470	19.366	980	40.494
480	19.792	990	40.885
490	20.218	1000	41.276
500	20.644

Cold-junction compensation. The tables are absolute, referenced to 0 °C. A real meter sees only the difference between the hot junction and its own terminals, so the millivolts at the meter equal E(hot) − E(cold junction). Set the reference to your terminal block temperature and the converter does it for you.

Still not reading right?

If the numbers here do not match what the loop is doing, the problem is usually the installation, the ranging, or the process itself rather than the device. Describe the symptom and a specialist answers by email, at no charge.

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