A thermocouple is a sensor for measuring temperature. It consists of two dissimilar metals, joined together at one end, which produce a small unique voltage at a given temperature. This voltage is measured and interpreted by a thermocouple thermometer. The phenomena is based on the Seebeck effect that occurs in electrical conductors that experience a temperature gradient along their length. Thermocouples are available in different combinations of metals or calibrations. The most common calibrations are J, K, T and R. Each calibration has a different temperature range and environment, although the maximum temperature varies with the diameter of the wire used in the thermocouple. Because thermocouples measure in many environments, it is important to ensure the correct sensor and sheath are selected. There are three main criteria to be considered when selecting a sensor: Temperature range Chemical resistance of the thermocouple or sheath material Abrasion, vibration and mechanical resistance
展开▼
