What's wrong with the three wires of the thermocouple

1. The principle of thermocouples
A thermocouple is a sensor that can convert temperature into a voltage signal. It consists of two different materials of wires, usually copper and copper nickel alloy. According to the Seebeck effect, when the contact point between two different materials is at different temperatures, a small electromotive force, also known as thermoelectric force, is generated. Using this principle, thermocouples can measure the temperature of an object.
2. Wiring method of thermocouples
There are various wiring methods for thermocouples, and the common one is the three wire connection method. These three wires are red, white, and blue respectively.
The red line is the "thermoelectric potential line", connected to the hot end of the thermocouple, which is the temperature point of the object being tested. The white line is the "cold end compensation line", connected to the cold end of the thermocouple, which is the reference temperature point of the external environment. The blue line is a "shielding wire" used to reduce the impact of external interference signals on thermocouple measurements.
3. The function of the three wires of the thermocouple
The different colors of the three wires of the thermocouple represent different functions and electrical signals, playing a role in protecting the thermocouple.
The thermoelectric potential signal received by the red line is generated by the temperature of the measured temperature point, and is used to measure the true temperature of the detected object. The white line is connected to the reference temperature point of the external environment to compensate for possible temperature errors in the thermoelectric potential signal. The blue line ensures the accuracy of thermocouple measurements by shielding external interference signals.
4. Use of Three Thermocouple Wires
When using thermocouples, connect the red line to the measured temperature point, the white line to the external reference temperature point, and the blue line to the metal casing to reduce interference signals. By measuring the voltage difference between the red and white lines, the temperature of the object being measured can be obtained.
Thermocouples are widely used in temperature measurement fields in various industries, such as industrial control, medical equipment, heat treatment processes, etc. Its accuracy and sensitivity make it a commonly used temperature measurement sensor.