Red Seal Instrumentation and Control Technician Exam 2026 – 400 Free Practice Questions to Pass the Exam

A thermocouple is a sensor that measures temperature by generating a voltage based on the junction of two different metals. This principle is rooted in the Seebeck effect, which states that when two dissimilar metals are joined at two points and there is a temperature difference between those points, a voltage is produced that is proportional to that temperature difference. This generated voltage can be measured and interpreted to provide an accurate temperature reading.

The construction of a thermocouple typically involves two wires made from different metal alloys, which are joined at one end (the measuring junction) while the other ends (the reference junction) are typically connected to a measuring device. The type of metals used and the configuration of the thermocouple influence its temperature range and accuracy.

This makes thermocouples widely utilized in various industries for temperature measurement applications due to their simplicity, robustness, and ability to function in extreme environments.