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What is a thermocouple?
A device that measures temperature using two different metals
How does a thermocouple generate voltage?
By the Seebeck effect
What are the main components of a thermocouple?
Two dissimilar metal wires and a measuring junction (hot junction).
What is the main function of a thermocouple?
To measure temperature by producing a voltage that depends on the temperature difference between two junctions.
What is meant by the “hot junction” of a thermocouple?
The hot junction is the point where the two metal wires are joined and exposed to the temperature being measured.
What is the working principle of a thermocouple?
It works based on the Seebeck effect, where a voltage is generated when two dissimilar metals experience a temperature difference.
Name one common type of thermocouple and its metals.
Type K thermocouple — made of Chromel (Nickel-Chromium) and Alumel (Nickel-Aluminum).
How does the Seebeck effect explain the working principle of a thermocouple?
When two different metals are joined and their junctions are at different temperatures, a voltage (Seebeck voltage) is generated, which is used to calculate temperature.
What is the function of the reference (cold) junction in a thermocouple?
To provide a comparison temperature for accurate measurement
In an exposed junction thermocouple, what is special about its construction?
The junction is exposed to the environment for faster response
What can cause measurement errors in thermocouples?
Electromagnetic interference or poor connections
Why must the reference (cold) junction temperature be compensated or controlled in precise thermocouple measurements?
Because any change in the reference junction temperature affects the voltage output, leading to errors in the measured temperature unless compensation is applied.