Thermocouple coiled extension wire is used to carry the signal from the thermocouple sensor to the readout device while maintaining a high degree of accuracy. 

The extension wire material must match the material used in the positive and negative leg of the thermocouple type (e.g. type K) being used in the application. If a transmitter is installed within the thermocouple sensor assembly, copper wire is typically used in place of thermocouple extension wire to send the scalable (4 to 20) mA signal back to the process control equipment.

We offer a variety of sizes and gauges of thermocouple grade and extension wire, as well as wire insulators. We also offer special construction thermocouple wire and RTD cable, including multi-pair thermocouple extension wire.

Thermocouple and extension wires are generally ordered and specified by ASTM/ANSI designations for calibration.

Popular generic and trade name examples are:

• Chromel®/Alumel® - ASTM/ANSI Type K
• Iron/Constantan - ASTM/ANSI Type J
• Copper/Constantan - ASTM/ANSI Type T
• Chromel®/Constantan - ASTM/ANSI Type E
• Nicrosil®/Nisil® - ASTM/ANSI Type N
• Platinum/Platinum (10% Rhodium) - ASTM/ANSI Type S
• Platinum/Platinum (13% Rhodium) - ASTM/ANSI Type R
• Platinum (6% Rhodium)/Platinum (30% Rhodium) - ASTM/ANSI Type B

Pyromation produces a wide range of thermocouples and thermocouple replacements for most market applications, including MgO (Magnesium Oxide), industrial and general-purpose types. We also make thermocouple assemblies for hazardous locations and other applications that require connection heads, protection tubes, thermowells and/or transmitters.

If you have a specific requirement or need a thermocouple you don't see listed just send us a note and we'll get you a quote

Thermocouple Temperature Limits and Color Codes

Thermocouple Initial Material Tolerances

General MgO Specifications