Thermocouple

Thermocouple sensors consist of two different metals and is used for measuring temperatures. This is the basic form of temperature sensors utilized for all type of temperature measurement. Different metal combinations usually used are NickelPlatinum, PlatinumRhodium, Tungsten alloy etc. It does not need any external voltage. The principle is that it produces a small voltage in proportion to the temperature which can then be converted into a digital signal. This voltage will be proportionate to the temperature. This can be displayed on a display device. A combination of two different metals produces a small voltage based on the variation in temperature. The voltage so generated can be termed as Thermoelectric voltage. Since this is a minute electric voltage, there is a limitation on the length of the cables in relation to the accuracy of the measurement. For longer distances, the accuracy is compromised. Hence it is preferred that the instrument is properly calibrated after installation to account for such corrections. Proper compensating cables are used to obtain more accurate results.