Thermocouple Wire Color Code
In the United States, the thermocouple color code is regulated via ANSI MC96.1, issued in 1982. Canadian ANSI/ ASTM E230 standard offers identical color coding. Note that the thermocouple color coding standards in the rest of the world are different from the North American Standard.
In the USA and Canada, the jackets of all thermocouple wires are brown unless no color is established ( like for types S, R, B, and C). With extension-grade cables, there is more variety in the color of insulation. Note that the color of insulation in thermocouple-grade and extension-grade wires are not the same.
For more information, visit our thermocouple wire guide. If you are choosing between Type K and Type J, this post will help. For thermocouple grade and thermocouple extension cables, visit Nassau National Cable.