Type K / J / E / N / T / R / S / B Thermocouple Extension Cable with PVC Sheath for -20~100℃ Temperature Range

Thermocouple compensation wire temperature measurement principle

The function of compensating wires for thermocouples is to extend the thermoelectric electrode, that is, move the cold end of the thermocouple, and connect it with the display instrument to form a temperature measurement system. The product is mainly used in various temperature measurement devices and has been widely used in departments such as petroleum, chemical, metallurgy, and power.

Generally speaking, thermocouples may be several tens of meters away from the thermometer, and the temperature at the cold end (outlet) of the thermocouple is different from the ambient temperature of the thermometer (even up to several tens of degrees).

If ordinary copper wires are used, according to the principle of thermocouples, the junction will generate thermoelectric potential, which will result in measurement errors.

The voltage drop problem of long-distance transmission wires is due to the high input impedance of the thermometer, the small transmission current (micro A level) generated by the thermocouple (millivolt level), and the small voltage drop loss on the wire, which is generally within the error range. So there is a thermocouple transmitter that inputs thermocouple signals and outputs 4-20mA, which allows for long-distance transmission without compensating for wires.

If a compensating wire is used (which must match the thermocouple graduation number), the metal material used can generate the smallest possible thermoelectric potential at the wiring point and minimize temperature measurement errors as much as possible. That is to say, move the cold end of the thermocouple to the thermometer.

• ​Standards

Working Temperature Range