A thermocouple is an electrical device used for measuring temperature. It consists of two dissimilar electrical conductors that are joined together at one end to form an electrical junction. When the junction is heated or cooled, a voltage is generated in the electrical circuit of the thermocouple, which can be measured and correlated back to the temperature. The voltage produced by the thermocouple is a result of the Seebeck effect.
Thermocouples are widely used as temperature sensors because they are inexpensive, interchangeable, and can measure a wide range of temperatures. They are self-powered and require no external form of excitation. Thermocouples are commonly used in science and industry for temperature measurement in kilns, gas turbine exhaust, diesel engines, and other industrial processes. They are also used in homes, offices, and businesses as temperature sensors in thermostats and as flame sensors in safety devices for gas-powered appliances.
There are different types of thermocouples, each with a different temperature range and environment. The most common types are the "Base Metal" thermocouples known as Types J, K, T, E, and N. There are also high-temperature calibrations, also known as Noble Metal thermocouples, such as Types R, S, C, and GB. The wire gauge determines the thermocouple type, and thinner materials cannot hold up to higher temperatures without being damaged.
To choose the right thermocouple for a specific application, it is important to consider factors such as the application where the thermocouple sensor will be used, the probe ranges the thermocouple will be exposed to, any chemical resistance needed for the thermocouple or sheath material, and the need for abrasion and vibration resistance.
