Thermocouples are temperature measuring sensors

As a temperature measuring sensor, thermocouple is used to directly measure or control the temperature of fluid, steam, gas medium and solid surface in the range of 0-1800 ℃ in various production processes. The armored thermocouple has many advantages such as bending, high pressure resistance, fast thermal response time and durability. Like the industrial assembled thermocouple, it is used as a sensor to measure temperature, usually in combination with display instrument, recording instrument and electronic regulator.
Working principle of thermocouple
The electric couple is welded together with two different components of conductors. When the temperature of both ends is different, there will be thermoelectric potential in the circuit. Therefore, the potential electric couple is a kind of temperature sensing element which measures the temperature by measuring the electric potential. It is a kind of converter, which can convert the temperature signal into the electric signal and then display it by the display instrument.
The basic principle of thermocouple temperature measurement is thermoelectric effect. It connects the head and tail of two different components of metal conductors into a closed circuit. If the temperature of the two contacts is not equal, thermoelectric EMF will be generated in the circuit to form thermal current, which is thermoelectric effect. Thermocouples are made by welding two different metal materials at one end. The welded end is called the measuring end, and the unwelded end is called the reference end. The reference end is usually constant at a certain temperature (such as 00C) when heating the measuring end, there is thermoelectric potential at the contact. For example, if the temperature of the reference end is constant, the magnitude and direction of the thermal potential are only related to the characteristics of the two metal materials and the temperature of the measuring end, but not to the fineness and length of the potential couple. When the temperature of the measuring end changes, the potential and potential will also change, and there is a fixed functional relationship between the temperature and the thermal potential, so the temperature can be measured by using this relationship.
Thermocouple electrode is a circuit formed by welding two ends of conductor with two different components. The direct temperature measuring end is called the working end, and the terminal end is called the cold end, also known as the reference end. When there is a temperature difference between the working end and the reference end, a thermal current will be generated in the circuit. When the display instrument is connected, the corresponding temperature value of the thermoelectric EMF generated by the thermocouple will be indicated on the instrument. The thermoelectric force of the thermocouple will increase with the temperature of the measuring end. The thermoelectric force is only related to the material of the thermocouple conductor and the temperature difference between the two ends, and has nothing to do with the length and diameter of the thermoelectric pole. The structure principle of the thermocouple is that it is made of conductor, high insulating magnesium oxide and outer stainless steel protective tube, which are pulled together for many times. Thermocouple products are mainly composed of junction box, terminal block and thermocouple, and equipped with various installation and fixing devices.

Temperature Sensor Thermocouple

Thermocouple Gas Temperature Sensor