2. INTRODUCTION
A thermocouple is a temperature-measuring device consisting of
two dissimilar conductors that contact each other at one junction.
It produces a voltage when the temperature of one of the ends
differs from the reference temperature at other end of the circuit.
Metal A
Metal B
Junction
Voltmeter
3. THERMOCOUPLES: SEEBECK EFFECT
The Seebeck effect is the conversion of thermal
energy/temperature differences directly into electrical energy or
electricity.
The change in the voltage is proportional to the temperature
difference between the junctions when the ends are connected to
form a loop.
4. PRINCIPLE OF OPERATION
The EMF generated by
the Seebeck effect is due
to the temperature
gradient along the wire.
The EMF is not generated
at the junction between
two dissimilar wires.
5. APPLICATIONS
1.Steel industry
2.Gas appliance safety
3.Thermopile radiation sensors
4.Manufacturing
5.Power production
6.Thermoelectric cooling
7.Process plants
8.Thermocouple as vacuum gauge
9. Heaters
6. A thermocouple (the right most tube) inside the burner
assembly of a water heater.
7. Thermocouple connection in gas appliances. The end ball (contact) on the left is
insulated from the fitting by an insulating washer. The thermocouple line consists
of copper wire, insulator and outer metal (usually copper) sheath which is also
used as ground.
12. DISCOVERED FACTS
• Construction of Thermocouple
• How thermocouple types are classified
based on material used?
• Seebeck effect
• Range of temperature that it operates
