TSC310

Thermocouples feature simple construction and robust durability. Thermocouple sensors measure temperature based on the Seebeck effect. Two dissimilar conductors are connected to form a closed loop. A tiny voltage difference will occur in the loop whenever the temperatures at the two junctions differ. This voltage difference is known as thermovoltage or thermoelectromotive force. Its magnitude depends on the materials of the two conductors, as well as the temperature difference between the "measuring junction" (the joint of the two conductors) and the "cold junction" (the open‑circuit ends of the conductors). For this reason, thermocouples are generally used only for differential temperature measurement. The absolute temperature at the measuring junction can be obtained if the cold‑junction temperature is known, or measured separately and compensated. The IEC 60584 and ASTM E230/ANSI MC96.1 standards list common thermocouple conductor material combinations together with their corresponding thermovoltage‑temperature characteristics.

Standard Application

Thermocouple probes are easy to install. They deliver reliable and accurate temperature measurement in general process applications and offer high operational safety. The probes are particularly suited for measuring gaseous and liquid media in mechanical equipment, laboratory instruments and plants, such as air, water and oil. Without an additional thermowell, the probe housing comes into direct contact with the process medium, enabling fast and accurate detection of instantaneous temperature changes.