Why do thermocouples use two different metals?

Different metals develop different voltages. Thus, if you connected two different metals and heat the junction, you can measure the voltage difference at the other end, and figure out the temperature.

What is the different between thermocouple and thermostat?

is that thermostat is thermostat while thermocouple is (physics) a transducer consisting of two different metals welded together at each end; a voltage is produced that is proportional to the difference in temperature between the two junctions (one of which is normally held at a known temperature).

When any two different metals are connected together what is generated?

Thermocouple. When two dissimilar metals are put into contact with each other, a small voltage in the millivolt range is generated. This junction emf is temperature dependent and can be used as a thermometer.

What are the different materials used for developing thermocouple?

Common thermocouple materials include copper/constantan (Type T), iron/constantan (Type J), and chromel/alumel (Type K). When several thermocouples, made of the same materials are combined in series, they are called a thermopile.

What is a thermocouple and how does it work?

Thermocouples work based on the principle that each wire will develop a voltage difference along it’s length when you heat or cool one end. Different metals develop different voltages. Thus, if you connected two different metals and heat the junction, you can measure the voltage difference at the other end, and figure out the temperature.

Why thermocouple cannot be formed without two junctions?

The thermocouple cannot be formed if the two junctions are not formed. Both the junctions are maintained at different temperatures. One is at the known temperature and the other at the unknown temperature. There are several combinations of the metals that can be used to form the thermocouple.

Why are metals that are heated dissimilar metals?

They are dissimilar metals because molecular difference, ie. electron difference of the metals. Heating the metals causes a very small exchange of free electrons between the metals called the Seebeck effect. This amounts to a very tiny measurable electrical current being established between the wires.

How do therthermocouples work?

Thermocouples work because the heat creates a thermoelectric voltage in the wire, this is known commonly as the ‘Seebeck effect’ (difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the two substances.).