A thermocouple is a temperature sensor based on the Seebeck effect, which generates a thermoelectromotive force through the temperature difference between two different conductors to achieve temperature measurement. It is widely used in industrial, scientific research, and other fields.
Basic Principle
The working principle of a thermocouple is based on the Seebeck effect, where two different conductors or semiconductors generate a thermoelectromotive force under a temperature difference. When there is a temperature difference between the measuring end (hot junction) and the reference end (cold junction) of the thermocouple, a thermal potential proportional to the temperature difference is formed in the circuit. By measuring this potential, the temperature can be calculated.
Core Structure
A thermocouple typically consists of the following components:
Thermoelectrodes: Two conductors made of different materials (such as platinum-rhodium alloy, nickel-chromium alloy, etc.) form a closed circuit.
Insulating Protective Tube: Prevents electrode short circuits and isolates harmful media.
Junction Box: Connects compensation wires and display instruments.
Main Features
Wide Temperature Measurement Range: Covers -270°C to 2800°C, suitable for extreme environments.
Fast Response Time: The response time of micro thermocouples can be as short as 4-6 seconds.
No External Power Supply Required: Directly outputs electrical signals, facilitating remote transmission and integration.
Simple and Durable Structure: High mechanical strength, resistant to vibration and impact.