Compensation cables

Compensation cables are manufactured as stranded conductors with various insulations and armouring. According to IEC / EN 60584-3, the compensation cable is designated with the letter "C", which is placed after the code letter of the thermocouple (e.g. "KC"). The electrical conductors of the compensation cable (i.e. the flexible strands) consist of so-called substitute materials which have a different chemical composition than the materials of the associated thermocouple. Different substitute materials may also be used for a type of thermocouple, whereby the designation of the compensation cables in this case is extended by an additional code letter "A" or "B" (e.g. "KCA" and "KCB"). The substitute materials have the same thermoelectric properties as the associated thermocouple in the temperature range permitted for compensation cables. Compensation cables are used for the thermocouple types K, N, R, S, and B, since the substitute materials (especially for the precious metal thermocouple types R, S, and B) are considerably less expensive than the (original) materials of the associated thermocouple. In addition, the substitute materials of a compensation cable have a lower loop resistance than the original materials. However, this positive property is of lesser importance, since the electronic measuring devices for compensation cables of present-day design have such a high input resistance that even cable resistances of a few kiloohms would not cause a significant measurement error.

The following Table 1 provides an overview of the materials and accuracy class of compensation cables with the corresponding thermocouples. The compensation cables shown in the list are available in the colour codes according to IEC/EN 60584-3. The compensation cables can also be supplied in other colours on request.