# What are working principle of thermocouple?

## What are working principle of thermocouple?

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.

## How does a thermocouple work and where is it used?

Thermocouples are electrical devices consisting of two dissimilar electrical conductors forming different electrical junctions at various temperatures. Building on the thermoelectric effect, a thermocouple produces temperature-dependent voltage, which can be used to measure temperature.

What is the application of thermocouples?

Applications include temperature measurement for kilns, gas turbine exhaust, diesel engines, and other industrial processes. Thermocouples are also used in homes, offices and businesses as the temperature sensors in thermostats, and also as flame sensors in safety devices for gas-powered appliances.

How is a thermocouple construction?

A thermocouple is constructed of two dissimilar wires joined at one end and encased in a metal sheath. The other end of each wire is connected to a meter or measuring circuit. Heating the measuring junction of the thermocouple produces a voltage that is greater than the voltage across the reference junction.

### What is output of thermocouple?

The output from a thermocouple is small, of the order of millivolts for a 10°C temperature difference, and Fig. 1.3 shows typical sensitivity and useful range for a variety of the common types. Of these, the copper/constantan type is used mainly for the lower range of temperatures and the platinum!

### What is thermocouple and its types?

A Thermocouple is a sensor used to measure temperature. Type J, K, T, & E are “Base Metal” thermocouples, the most common types of thermocouples. Type R, S, and B thermocouples are “Noble Metal” thermocouples, which are used in high temperature applications (see thermocouple temperature ranges for details).