NIST Temperature Scale Database (SRD 60), Version 3.0
Reference Function Coefficients:
The general form for the emf E (mV) as a function of T90 (°C) is:
Notes: Six of thermocouple types (B, E, J, K, N, T) have two reference functions for different temperature ranges, while Type R and S have three temperature regions.
For Type K thermocouples above 0 °C, there is an additional term to account for a magnetic ordering effect:
where constants a0, a1, and a2 are: a0 = 0.118597600000 *100, a1 = -0.118343200000*10-3, a2 = 0.126968600000x10*103
| Type | Range | Ti (°C) | Tf (°C) | Ord | c0 | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c9 | c10 | c11 | c12 | c13 | c14 | a1 | a2 | a3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| B | 1 | 0.000 | 630.615 | 6 | 0.00E+00 | -2.47E-04 | 5.90E-06 | -1.33E-09 | 1.57E-12 | -1.69E-15 | 6.30E-19 | |||||||||||
| 2 | 630.615 | 1820.000 | 8 | -3.89E+00 | 2.86E-02 | -8.49E-05 | 1.58E-07 | -1.68E-10 | 1.11E-13 | -4.45E-17 | 9.90E-21 | -9.38E-25 | ||||||||||
| E | 1 | -270.000 | 0.00 | 13 | 0.00E+00 | 5.87E-02 | 4.54E-05 | -7.80E-07 | -2.58E-08 | -5.95E-10 | -9.32E-12 | -1.03E-13 | -8.04E-16 | -4.40E-18 | -1.64E-20 | -3.97E-23 | -5.58E-26 | -3.47E-29 | ||||
| 2 | 0.000 | 1000.00 | 10 | 0.00E+00 | 5.87E-02 | 4.50E-05 | 2.89E-08 | -3.31E-10 | 6.50E-13 | -1.92E-16 | -1.25E-18 | 2.15E-21 | -1.44E-24 | 3.60E-28 | ||||||||
| J | 1 | -210.000 | 760.00 | 8 | 0.00E+00 | 5.04E-02 | 3.05E-05 | -8.57E-08 | 1.32E-10 | -1.71E-13 | 2.09E-16 | -1.25E-19 | 1.56E-23 | |||||||||
| 2 | 760.000 | 1200.00 | 5 | 2.96E+02 | -1.50E+00 | 3.18E-03 | -3.18E-06 | 1.57E-09 | -3.07E-13 | |||||||||||||
| K | 1 | -270.000 | 0.00 | 10 | 0.00E+00 | 3.95E-02 | 2.36E-05 | -3.29E-07 | -4.99E-09 | -6.75E-11 | -5.74E-13 | -3.11E-15 | -1.05E-17 | -1.99E-20 | -1.63E-23 | |||||||
| 2 | 0.000 | 1372.00 | 9 | -1.76E-02 | 3.89E-02 | 1.86E-05 | -9.95E-08 | 3.18E-10 | -5.61E-13 | 5.61E-16 | -3.20E-19 | 9.72E-23 | -1.21E-26 | 1.18597600000E-01 | -1.18343200000E-04 | 1.26968600000E+02 | ||||||
| N | 1 | -270.000 | 0.00 | 8 | 0.00E+00 | 2.62E-02 | 1.10E-05 | -9.38E-08 | -4.64E-11 | -2.63E-12 | -2.27E-14 | -7.61E-17 | -9.34E-20 | |||||||||
| 2 | 0.000 | 1300.00 | 10 | 0.00E+00 | 2.59E-02 | 1.57E-05 | 4.38E-08 | -2.53E-10 | 6.43E-13 | -1.01E-15 | 9.97E-19 | -6.09E-22 | 2.08E-25 | -3.07E-29 | ||||||||
| R | 1 | -50.000 | 1064.18 | 9 | 0.00E+00 | 5.29E-03 | 1.39E-05 | -2.39E-08 | 3.57E-11 | -4.62E-14 | 5.01E-17 | -3.73E-20 | 1.58E-23 | -2.81E-27 | ||||||||
| 2 | 1064.180 | 1664.50 | 5 | 2.95E+00 | -2.52E-03 | 1.60E-05 | -7.64E-09 | 2.05E-12 | -2.93E-16 | |||||||||||||
| 3 | 1664.500 | 1768.10 | 4 | 1.52E+02 | -2.69E-01 | 1.71E-04 | -3.46E-08 | -9.35E-15 | ||||||||||||||
| S | 1 | -50.000 | 1064.18 | 8 | 0.00E+00 | 5.40E-03 | 1.26E-05 | -2.32E-08 | 3.22E-11 | -3.31E-14 | 2.56E-17 | -1.25E-20 | 2.71E-24 | |||||||||
| 2 | 1064.180 | 1664.50 | 4 | 1.33E+00 | 3.35E-03 | 6.55E-06 | -1.65E-09 | 1.30E-14 | ||||||||||||||
| 3 | 1664.500 | 1768.10 | 4 | 1.47E+02 | -2.58E-01 | 1.64E-04 | -3.30E-08 | -9.43E-15 | ||||||||||||||
| T | 1 | -270.000 | 0.00 | 14 | 0.00E+00 | 3.87E-02 | 4.42E-05 | 1.18E-07 | 2.00E-08 | 9.01E-10 | 2.27E-11 | 3.61E-13 | 3.85E-15 | 2.82E-17 | 1.43E-19 | 4.88E-22 | 1.08E-24 | 1.39E-27 | 7.98E-31 | |||
| 2 | 0.000 | 400.00 | 8 | 0.00E+00 | 3.87E-02 | 3.33E-05 | 2.06E-07 | -2.19E-09 | 1.10E-11 | -3.08E-14 | 4.55E-17 | -2.75E-20 |