Compensating wires are suitable for use in metallurgy, petrochemicals, power, and other fields. They consist of alloy wire, insulation, and a sheath, and are available in extension and compensation types. They are also classified by accuracy as standard and precision grades, with a typical operating temperature range of 0~100℃.
These wires extend the cold junction to a temperature-stable region by matching the thermoelectric potential characteristics of the thermocouple, thus eliminating measurement errors. They are typically made of copper-nickel alloy or nickel-chromium alloy. When using them, it is crucial to ensure strict correspondence between the calibration numbers, connect the positive terminal to the red wire, and ensure the line resistance meets instrument requirements. Wiring should be done away from interference sources and the length controlled. For high-temperature environments, heat-resistant models with fluoroplastic sheaths should be selected. Compensating wires are available in shielded and unshielded types, with common models including SC, KC, and KX.
These are specialized wires used to extend the cold junction of a thermocouple to a location away from high temperatures and with a relatively stable temperature. Essentially, they are thermocouples composed of two different metals. Within a certain temperature range, their thermoelectric characteristics are essentially the same as those of the main thermocouple. By connecting compensating wires to the cold junction of the thermocouple, the temperature signal output by the thermocouple can be transmitted to a control room tens of meters away, and then sent to display or control instruments. This is equivalent to extending the thermocouple to a place with a constant temperature, solving the problem of high temperature and temperature instability caused by the cold junction of the thermocouple near hot equipment. It is convenient to use and is frequently used in thermocouple installation. These are specialized wires; one type of compensating wire can only be used with one corresponding type of thermocouple, and the positive and negative polarities must not be reversed.
