A thermocouple is a device used extensively for measuring temperature.
A thermocouple is composed of two wires made from dissimilar metals. These two wires are joined to form a temperature measurement junction. Each wire is made of a specific metal or metal alloy. For example, the positive (+) conductor of a type K thermocouple is made of a chromium/nickel alloy called chromel and the negative (-) conductor is made of an aluminium /nickel alloy called alumel. Wire used to make a thermocouple junction is called thermocouple wire.
How Do I Choose a Thermocouple
- Determine the application for which the thermocouple will be used.
- Note the maximum and minimum temperatures the thermocouple will be exposed to.
- Factor in any chemical resistance required for the thermocouple .
- Evaluate the need of abrasion and vibration resistance.
- List any installation requirements
Advantages of the Thermocouples:-
• Thermocouples are used on most transformers. The hot junction is inside the transformer oil and the cold junction at the meter mounted on the outside.
• In general, thermocouples are used exclusively around the turbine hall because of their rugged construction and low cost.