A thermocouple is a temperature sensor that consists of two different metal wires or elements that are joined together at one end. When the joined end of the thermocouple is exposed to temperature difference, a small voltage is generated between the two wires, which is proportional to the temperature difference.
A thermocouple is a temperature sensor that consists of two different metal wires or elements that are joined together at one end. When the joined end of the thermocouple is exposed to temperature difference, a small voltage is generated between the two wires, which is proportional to the temperature difference.
How It Works | The Seebeck Effect
The operation of a thermocouple is based on the Seebeck effect, which is the phenomenon of a voltage being generated when two different metals are joined together, and one end is exposed to a temperature difference. The Seebeck effect is a result of the fact that different metals have different electron configurations and therefore different electron energies. When two different metals are joined together, electrons flow from the metal with the higher electron energy to the metal with the lower electron energy, creating a voltage.
Common Thermocouple Applications
Thermocouples are commonly used in temperature measurement applications because they are simple, inexpensive, and can measure a wide range of temperatures. They are also highly durable and can operate in harsh environments. Thermocouples are commonly used in applications such as industrial process control, automotive, aerospace, and laboratory testing.
Types of Thermocouples
There are several types of thermocouples, which are classified according to the types of metals used in the construction of thermocouple wires. The most used in industrial applications are Type J and Type K thermocouples. Each type has different temperature ranges, accuracy levels, and environmental limitations. Below is a chart that shows the different types of thermocouples and their associated optimal temperature ranges along with their wire color coding.
Proheat is an authorized distributor of industrial thermocouples, including brands like Chromalox and Watlow.
