What is the difference between thermocouple wires and compensating wires?

Thermocouple wires have the same function as thermocouples and are used for temperature measurement.

The compensation wire is only used to extend the thermocouple signal to the instrument that reads this signal, and is divided into two types: compensation wire (KC) and extension wire (KX).

Compensation type wires are generally made of alloy materials that have the same or similar thermoelectric potential as the thermocouple body in low-temperature environments (usually 0-150 ℃), such as the alloy of K-type thermocouples

Material (+nickel chromium nickel aluminum), KX's material is also+nickel chromium nickel aluminum, while KC compensation wire uses alloy material (+copper constantan). Within the temperature range of 100 degrees, KC compensation wire and K-type thermocouple.

It has similar thermoelectric potential and is much cheaper than KX extension cables, achieving a balance between performance and price. However, when the temperature exceeds 100 ℃, there will be a conflict between the thermoelectric potential of KC and the thermoelectric potential of K-type thermocouples, which will affect the accuracy.

So the KC compensation wires we usually see use PVC insulation material, because the maximum operating temperature of PVC insulation material is only 105 ℃.

The alloy material used for kx compensation wire is the same as that of K-type thermocouple, which can be used at high temperatures with almost no impact on accuracy, but the price is relatively expensive compared to kc compensation wire.

*It should be emphasized that thermocouple wires can be used as thermocouple extension wires, but thermocouple extension wires cannot be used as thermocouple wires.