A thermocouple is a simple but highly effective temperature sensor that uses the joining of wires made from two different metals or alloys to produce a voltage measure and thereby determine the heat range that exists within a particular area. It is especially useful for gauging temperature in applications where other means of heat measurement may be difficult and a wide variety of industries use the thermocouple as part of their daily operations. Here is a brief overview of how it works and its many uses. rtd
How a Thermocouple Works
Two different metal wires are joined at one end by the thermocouple while the other ends (called outputs) are attached to the environments being measured. The principle that drives this sensor is called the Seebeck effect wherein two metals joined together will produce electric voltage. In a nutshell, the higher the heat temperature coming into the output, the higher the generated voltage will be. A scientist, engineer or technician uses the voltage measure to gauge whether or not the ambient temperature they are measuring is remaining within acceptable parameters for that particular application.
Different types of metals joined together by a thermocouple will naturally produce various levels of voltage, so the types of materials and thermocouples needed depends on the temperature range in the area being measured. These different types of thermocouples are usually designed with their own letter (i.e. “K”) and are appropriate only for specific temperature ranges (-40 degrees C to 333 degrees C, for example).
Any significant change in voltage is an indication that the heat parameters in the measured environment are not being met, and serves as a warning sign to scientists in many different industries, including: