How is a good measurement made with thermocouples?


The use of these temperature sensors is valued based on the use and the temperature range. The thermocouple is an extremely simple and reliable sensor that is made up of two metallic materials of diverse nature joined by two junctions called “cold junction” and “hot junction”. The degree of temperature detected by these junctions generates a potential difference that is closely dependent on the nature of the materials. The installation of these sensors normally requires the use of special cables for high temperatures.

Thermocouples are normally built in such a way that they adapt to the working conditions. The fundamental data to obtain the applicable thermometric element are: Temperature range, type of thermocouple, diameter of the wires and length. The temperature range of the thermometric elements is given by the calibration and tolerance table, while the wire diameter is given by the maximum temperature of use and the considered response time. If a large diameter cable is placed, the duration of the element will be longer but the response time will always be lower. The length of the sensor element is given as a function of the type of use and the structure of the work process, as well as the type of protection of the thermometric element.