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How to Build a Thermocouple

Thermocouples are temperature sensors that are constructed from two different metals. When the metals are brought together to form a junction, they will produce a voltage when set at different temperatures. Thermocouples are important because they are small and dependable, which allows them to be used in devices such as medical thermometers and water heaters. They are able to function in extreme cold or extreme heat. Building a thermocouple is fairly easy, using paper clips and bare copper wire.

Things You'll Need

2 paper clips
Pliers
Copper wire
Digital multimeter
Alligator clips
Candle

Instructions

- 1
  Straighten one of the paper clips with the pliers. It does not have to be perfect. Do the same to the second paper clip.
- 2
  Cut several inches of the copper wire. The wire must be long enough to twist around the paper clips. If necessary, strip the insulation from it so that it is completely bare.
- 3
  Twist one end of the copper wire around the top of the first paper clip. Twist the other end of the wire to the second paper clip. The shape can look like an H, and does not have to be perfect.
- 4
  Attach the red probe of the multimeter to one paper clip, and the black probe to the other. Use alligator clips so that the probes will not slip off. Switch the multimeter to the DC millivolts setting, and turn it on.
- 5
  Place one of the top ends or joints of the thermocouple over the lit candle. Observe and record the multimeter voltage. Remove the device from the flame after you've recorded the reading.

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