termoelementet

A termoelementet, commonly known as a thermocouple, is a temperature-measuring device. It consists of two dissimilar electrical conductors, typically metal wires, joined together at one end. This junction is called the measuring junction or hot junction. The other ends of the wires are connected to a measuring instrument and form the reference junction or cold junction.

When the measuring junction is at a different temperature than the reference junction, a small voltage, known as the Seebeck voltage, is generated. This voltage is directly proportional to the temperature difference between the two junctions. The magnitude and polarity of the voltage depend on the types of metals used and the temperature difference. By measuring this voltage, the temperature at the measuring junction can be determined, provided the temperature of the reference junction is known or maintained at a constant, defined temperature.

Thermoelements are widely used in various industrial and scientific applications due to their robustness, wide temperature range, and relatively low cost. They can withstand harsh environments and measure temperatures from cryogenic levels up to several thousand degrees Celsius. Different combinations of metals are used to create various types of thermocouples, each suited for specific temperature ranges and environments, such as Type K (chromel-alumel), Type J (iron-constantan), and Type T (copper-constantan). The choice of thermocouple type depends on the required accuracy, temperature range, and the presence of corrosive substances.