A compensation cable is a specialized cable used to connect thermocouples to measuring instruments. Its primary function is to compensate for measurement errors caused by temperature changes at the connection point.

Core Definition

A compensation cable consists of one or more pairs of insulated conductors. Within a specified temperature range (including ambient temperature), its nominal thermoelectric electromotive force (EMF) matches that of the thermocouple it is paired with. It is used to connect the thermocouple to the measuring device, compensating for errors caused by temperature variations at the junction between them and the thermocouple.

Working Principle

The voltage signal generated by a thermocouple is proportional to the temperature difference between the measuring end and the reference end (cold junction). In actual industrial measurement, the reference end temperature usually cannot be maintained at the standard 0°C and fluctuates with the environment. The role of the compensation cable is to extend the cold junction of the thermocouple from the site with large temperature fluctuations to a control room or instrument end with a relatively stable temperature, thereby reducing measurement errors.