Temperature Measurement · Glossary

What is the Seebeck Effect?

thermoelectric voltageTemperature Measurement

The Seebeck effect is the voltage generated in a conductor along which there is a temperature gradient; it is how thermocouples work.

Seebeck Effect Explained

Each metal develops a voltage along a temperature gradient. Two different metals joined together develop different voltages, and the difference appears at the open ends.

Because the voltage is generated along the wire, any inhomogeneous section of wire in a gradient causes error. This is why aged thermocouples drift.

Seebeck Effect Formula

E = ∫ (S_A − S_B) dT

S_A, S_B	Seebeck coefficients of the two wires
dT	temperature change along the wires

Calculators for Seebeck Effect

CalculatorThermocouple CalculatorFree online calculator with formula and worked example.CalculatorThermocouple TableFree online calculator with formula and worked example.

Frequently Asked Questions

What is the Seebeck Effect?

The Seebeck effect is the voltage generated in a conductor along which there is a temperature gradient; it is how thermocouples work.

Is the voltage made at the junction?

No. It is generated along the wires where the temperature changes; the junction just connects them.

Why do connectors need thermocouple alloys?

Copper connectors in a temperature gradient create extra junctions and errors.

Learn more on the blog

Thermocouple and RTD installation precautions

A practical guide on instrumentationblog.in with more detail on seebeck effect and how it is applied on real plants.

Read Full Article

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