Extension grade thermocouple wire is used to complete the thermocouple circuit from the thermocouple element to the temperature instrument. Note that extension grade wire should not be used to make thermocouple elements. Extension wires can be divided into two categories. Category 1 extension wires are made with conductors which are the same as the thermocouple. Category 2 extension wires are made with conductors which are different from the the thermocouple. The base metal thermocouples are used with Category 1 extension wires. Noble metal and a few nonstandard thermocouples are used with Category 2 extension wires. The extension wire and thermocouple wire must both be of the same calibration type to maintain the accuracy of the thermocouple. The polarity of each set of wires must also be maintained during installation in order for the thermocouple circuit to function properly. The RED wire is always the NEGATIVE leg of the extension wire. Extension grade wire is also color coded to help with identification and installation. See the extension grade wire color code table in this catalog. If the extension wire will be subject to repeated flexing, a stranded wire should be used to prevent fatigue and failure. For typical, non-flexing, ambient temperature, indoor use, a 20 gauge (1.3mm) solid conductor with PVC insulation wire is an excellent choice. Note: Never install extension wire in the same conduit as power lines. This will cause interference and errors in the temperature readings. It is a good practice to keep the extension wire at least 1 foot away from power lines to maintain an accurate thermocouple circuit.

S = Stranded OB8 = Over braid 304ss OB9 = Over braid alloy 600 Ga. = Wire Gauge

Special Grade wire available on request. Double Type designation letter.
Example: 20KX-GG --> 20KKX-GG

Quantity shipped may vary plus or minus 10% from quantity ordered unless otherwise
arranged.

Armored Cable (304ss) on extension wire can be made to custom lengths.