{"id":13053,"date":"2021-12-26T10:00:43","date_gmt":"2021-12-26T18:00:43","guid":{"rendered":"https:\/\/www.linquip.com\/blog\/?p=13053"},"modified":"2026-02-21T00:27:06","modified_gmt":"2026-02-21T08:27:06","slug":"working-principle-of-thermocouple","status":"publish","type":"post","link":"https:\/\/www.linquip.com\/blog\/working-principle-of-thermocouple\/","title":{"rendered":"Working Principle of Thermocouple: 2026 Guide + Diagram"},"content":{"rendered":"

To understand the working principle of thermocouple, we must first understand its definition:<\/span><\/p>\n

The thermocouple is a type of temperature sensor that measures temperature at a single spot in the form of an EMF or an electric current. Because the quantity of EMF produced in the device is very small (millivolts), highly sensitive instruments must be used to calculate the EMF produced in the circuit. These are active transducers since they operate on the energy conversion concept. Their operation does not need the use of any form of power. These are essential temperature sensors that measure temperature as EMF. Certain metal combinations must be utilized to construct a thermocouple pair. These metal combinations are chosen in such a way that a linear rise in EMF is created as the temperature of the circuit rises.<\/span><\/p>\n

This article outlines the definition, and the working principle of thermocouple. So, do not miss this article at Linquip.<\/span><\/p>\n

\"working<\/p>\n

\u00a0<\/span>Working Principle of Thermocouple<\/b><\/h2>\n

In this part, we go through the working principle of thermocouple and the instruments required for the operation. So, let us begin with the subject:<\/span><\/p>\n

When two metals with different work functions come together, a voltage is created at the junction. This voltage is proportional to the temperature, and this junction is referred to as a \u201cthermocouple.\u201d<\/span><\/p>\n

The thermocouple operates on three effects including the \u201cSeebeck effect\u201d, the \u201cPeltier effect\u201d, and the \u201cThomson effect\u201d. The issue now is, what are these effects?<\/span><\/p>\n

Let\u2019s discuss in detail below:<\/span><\/p>\n

1) Seebeck effect:<\/b><\/h3>\n

A physicist named “Thomas Seebeck” discovered in 1821 that when two distinct metal wires are linked in a circuit at both ends of a junction, the temperature applied to the junction equals the current flowing through the circuit. It is referred to as the electromagnetic field (EMF). The energy produced by this circuit is referred to as the Seebeck effect. The quantity of induced EMF varies with metal combination and is related to the temperature differential between the junctions. This is the fundamental functioning principle of a thermocouple. In a nutshell, it is a phenomenon in which the temperature differential between two metals causes potential differences between them.<\/span><\/p>\n

2) Peltier effect:<\/b><\/h3>\n

The Peltier effect is an important part of the thermocouple’s operation. This effect is the polar opposite of the See beck effect. The Peltier effect demonstrates that by introducing a potential difference between two distinct types of conductors, a temperature differential may be generated. The thermocouple<\/a> circuit is made up of two metals that are linked together to produce two temperature junctions. The difference in temperatures between the circuit’s two junctions generates a Peltier EMF. The total EMF within the circuit may be calculated using the junction temperature and the characteristics of the metals employed in the circuit. A body with an unknown temperature is attached to one of the circuit’s connections, known as the hot junction. Another body with a known temperature is linked to the other connection, which is known as the cold or reference junction. To directly measure the voltage or current output from the thermocouple circuit, a voltmeter is attached to the thermocouple circuit.<\/span><\/p>\n

Read More on Linquip<\/strong><\/em><\/p>\n