# What is the basic principle of thermocouples?

## What is the basic principle of thermocouples?

The thermocouple working principle is based on the Seeback Effect. This effect states that when a closed circuit is formed by jointing two dissimilar metals at two junctions, and junctions are maintained at different temperatures then an electromotive force (e.m.f.) is induced in this closed circuit.

What is the range of temperature using thermocouple?

Depending on the metal wires used, a thermocouple is capable of measuring temperature in the range –200°C to +2500°C.

What is a thermocouple for kids?

A thermocouple, TC for short, is a device that converts heat directly into electricity. A thermocouple can also work in reverse – using an electric current to transform into heat as well as cold.

### What are characteristics of thermocouples?

Thermocouples are a common passive sensing element that respond to temperature in a measurable way. They are self-powered, requiring no excitation, and can operate over a wide temperature range (up to to 2000°C). They can respond quickly, with almost no significant delay in system operation.

How do you calculate the temperature of a thermocouple?

Go to the table for the thermocouple being used and look up the millivoltage produced at that temperature. Add that millivoltage to the millivoltage measured as “VD” to get a total. Find that millivoltage total in the reference table. The corresponding temperature is the temperature of the measuring junction.

What is the max temperature of a thermocouple?

Temperature Range: The different thermocouple types have different temperature ranges. For example, Type T with its Copper leg has a max temperature of 370C or 700F. Type K on the other hand can be used up to 1260C or 2300F.

#### Are there any color codes for thermocouples?

The color code for such thermocouples are either red or white with red tracer. All of the refractory types of thermocouples are having temperature ranges from 32 till 4200 degrees Fahrenheit. The main usages of such thermocouples are mainly in the vacuum furnaces which are having temperature ranges beyond the temperature capacity of platinum.

Why are Type K thermocouples so popular?

Type K thermocouples are so popular because of their wide temperature range and durability. The conductor materials used in Type K thermocouples are more chemically inert than Type T (copper) and Type J (Iron).

What kind of thermocouples are used in vacuum furnaces?

The main usages of such thermocouples are mainly in the vacuum furnaces which are having temperature ranges beyond the temperature capacity of platinum. These types of thermocouples are rarely used in applications where temperature range is below 2500 degrees Fahrenheit.

13/12/2019