Thermocouple compensation wire works
How does thermocouple compensation wire work? In the case of
The compensation wire is commonly used for link signal transmission between thermocouples and secondary meters. What is the role of the thermocouple compensation wire principle to keep the temperature on the entire line constant? In this case, the cold side of the temperature is the temperature of the hot end or compensate the role of the wire, the thermal side of the voltage difference spread to the cold end? But the voltage through the wire, then there will be pressure drop.
In general, the thermocouple from the thermometer may be tens of meters away from the thermocouple cold end (outlet) temperature and temperature table temperature is different (even up to several degrees).
If the ordinary copper wire, according to the thermocouple principle, the wiring will produce temperature difference potential, it will produce measurement error.
If the compensation wire (must be matched with the thermocouple degree), it uses the metal material, you can produce as little as possible in the wiring temperature difference potential, as far as possible to reduce the temperature error. In other words, the thermocouple cold end moved to the thermometer.
Long-distance transmission of the wire voltage drop problem, because the thermometer input impedance is high, thermocouple temperature difference potential (millivolt) transmission current (micro A-level) is very small, the wire pressure drop is very small, in general Under the error range. So there are thermocouple transmitter, enter the thermocouple signal, the output 4-20ma, so you can not compensate for the wire, you can also long-distance transmission.
