The resistance data presented below in ohms per foot for each thermocouple leg and ohms per double foot for the full thermocouple is calculated from electrical resistivity data provided in ohms-cm1 divided by the wire cross sectional area and adjusted for ohms/foot units. Since the wire manufacturing process does not result in perfectly uniform wire diameters, the wire area may vary and as such the resistance values shown below may also vary and are approximations.
K Thermocouple / Nickel-Aluminum (Alumel)
| Wire Size (AWG) |
Positive Wire Nickel-Chromium (Chromel) (Ω/ft) |
Negative Wire Nickel-Aluminum (Alumel) (Ohms/ft) |
Both Wires (Ω/double ft) |
| 16 | 0.164 | 0.068 | 0.233 |
| 20 | 0.416 | 0.173 | 0.589 |
| 24 | 1.051 | 0.437 | 1.488 |
| 30 | 4.225 | 1.757 | 5.982 |
| 36 | 16.968 | 7.056 | 24.024 |
| 40 | 43.099 | 17.922 | 61.021 |
J Thermocouple +Iron/ - Copper Nickel (Constantan)
| Wire Size(AWG) |
Positive Wire Iron (Ω/ft) |
Negative Wire Copper Nickel (Constantan) (Ω/ft) |
Both Wires (Ω/double ft) |
| 16 | 0.029 | 0.114 | 0.143 |
| 20 | 0.074 | 0.288 | 0.361 |
| 24 | 0.186 | 0.727 | 0.913 |
| 30 | 0.747 | 2.922 | 3.670 |
| 36 | 3.000 | 11.736 | 14.736 |
| 40 | 7.620 | 29.809 | 37.429 |
T Thermocouple + Copper/ - Copper-Nickel (Constantan)
| Wire Size (AWG) | Positive Wire(Ω/ft) | Negative Wire(Ω/ft) | Both Wires (Ω/double ft) |
| 16 | 0.004 | 0.114 | 0.118 |
| 20 | 0.010 | 0.288 | 0.298 |
| 24 | 0.025 | 0.727 | 0.752 |
| 30 | 0.102 | 2.922 | 3.025 |
| 36 | 0.410 | 11.736 | 12.146 |
| 40 | 1.042 | 29.809 | 30.852 |
E Thermocouple + Copper/ - Copper-Nickel(Constantan)
| Wire Size (AWG) | Positive Wire(Ω/ft) | Negative Wire(Ω/ft) | Both Wires (Ω/double ft) |
| 16 | 0.163 | 0.114 | 0.277 |
| 20 | 0.412 | 0.288 | 0.700 |
| 24 | 1.041 | 0.727 | 1.768 |
| 30 | 4.184 | 2.922 | 7.106 |
| 36 | 16.800 | 11.736 | 28.536 |
| 40 | 42.672 | 29.809 | 72.481 |
N Thermocouple + Nicrosil / - Nisil
| Wire Size (AWG) | Positive Wire(Ω/ft) | Negative Wire(Ω/ft) | Both Wires (Ω/double ft) |
| 16 | 0.233 | 0.085 | 0.318 |
| 20 | 0.588 | 0.215 | 0.803 |
| 24 | 1.487 | 0.543 | 2.030 |
| 30 | 5.976 | 2.181 | 8.158 |
| 36 | 24.000 | 8.760 | 32.760 |
| 40 | 60.960 | 22.250 | 83.210 |
S Thermocouple + Platinum 10% Rhodium/ - Platinum
| Wire Size (AWG) | Positive Wire(Ω/ft) | Negative Wire(Ω/ft) | Both Wires (Ω/double ft) |
| 16 | 0.044 | 0.025 | 0.068 |
| 20 | 0.111 | 0.062 | 0.173 |
| 24 | 0.280 | 0.158 | 0.437 |
| 30 | 1.124 | 0.634 | 1.757 |
| 36 | 4.512 | 2.544 | 7.056 |
| 40 | 11.460 | 6.462 | 17.922 |
R Thermocouple + Platinum 13% Rhodium/ - Platinum
| Wire Size (AWG) | Positive Wire(Ω/ft) | Negative Wire(Ω/ft) | Both Wires (Ω/double ft) |
| 16 | 0.046 | 0.025 | 0.070 |
| 20 | 0.115 | 0.062 | 0.178 |
| 24 | 0.291 | 0.158 | 0.449 |
| 30 | 1.171 | 0.634 | 1.805 |
| 36 | 4.704 | 2.544 | 7.248 |
| 40 | 11.948 | 6.462 | 18.410 |
B Thermocouple + Platinum 30% Rhodium/ - Platinum 6%Rhodium
| Wire Size (AWG) | Positive Wire(Ω/ft) | Negative Wire(Ω/ft) | Both Wires (Ω/double ft) |
| 16 | 0.044 | 0.045 | 0.088 |
| 20 | 0.111 | 0.113 | 0.224 |
| 24 | 0.280 | 0.285 | 0.565 |
| 30 | 1.124 | 1.147 | 2.271 |
| 36 | 4.512 | 4.608 | 9.120 |
| 40 | 11.460 | 11.704 | 23.165 |