Home >> Science & Nature >> Science

How to Make a Thermocouple Battery

A thermocouple consists of two connections or junctions between two dissimilar metals, usually wires, with one junction heated and the other cooled. The junctions are known as the "hot end" and the "cold end." A voltage called the Seebeck voltage, named for its discoverer, J.T Seebeck, flows across the open circuit at the cold end of the circuit and is proportional to the temperature difference between the hot and cold junctions.

Things You'll Need

Soft iron wire
Copper wire
Ice
Candle
Terminal strip

Instructions

- 1
  Cut one length of iron wire and one of copper wire, each roughly 18 inches long. Strip the insulation from both wires.
- 2
  Rest the wires side-by-side and twist them together at one end. Twist tightly to form a joint about 1 inch long. This is the hot end. Connect the free ends -- the cold end -- to a terminal strip. Leave sufficient space between the bare wires to keep them apart throughout their length.
- 3
  Connect the terminal block to a sensitive voltmeter capable of reading microvolt to millivolt voltages. Set the voltmeter to its most sensitive voltage setting and switch it on.
- 4
  Place a lighted candle under the twisted junction of the wires and apply direct heat. Observe the voltmeter connected to your thermocouple battery. Increasing the temperature at the junction causes a temperature difference between the ends of the wires and the thermocouple battery produces a voltage.

Science