What is the relationship between Voltage and Temperature for a Thermoelectric Device?

Objective: Upon completion of this lab you will have a graph that describes the relationship between voltage and temperature for a thermoelectric device (TED). This graph will serve as a quick reference to determine the voltage output for a given temperature difference. Graphs, like the one you will produce, are used by engineers to determine if a particular device is appropriate for a particular situation.

Materials:

1 thermoelectric device (TED)

1 soldering iron

1 Volt Ohm Meter (VOM)

1 infrared thermometer

2 heat sinks (a piece of ¼” aluminum plate just larger than the TED)

Heat conductive grease

Graphing software

Procedure:

  1. It is recommended that students work in teams of three: One to hold the soldering iron, one to use the thermometer, and one to record the data.
  2. Connect the leads of the VOM to the TED. As data collection begins, if the voltage is negative reverse the leads.
  3. Plug in the soldering gun so it can begin to heat.
  4. Place a small bead of heat conductive grease on each of the white surfaces of the TED. Spread it to completely cover with a thin coat. Try to keep the grease from getting in the small square pockets that surround the edges. Place a heat sink in each side of the TED, making a TED sandwich.
  5. Lay the sandwich down on the lab table in a comfortable place that will allow you to hold the soldering on top of the sandwich and be able to take temperature measurements of the top and bottom sink.
  6. Use caution with the Soldering Iron. Hold the soldering iron at an angle that will provide the most amount of contact between the tip and the upper heat sink. Touch the soldering iron to the heat sink.
  7. Switch the VOM to the on position and adjust the range to 20 volts.
  8. Aim the infrared thermometer at the lower heat sink and record the temperature. Aim the thermometer at the upper heat sink when the temperature of the upper heat sink is approximately 10 degrees above the lower heat sink. Record the temperature and the voltage.
  9. Repeat this procedure every time the upper heat sink temperature is 10 degrees warmer than it was before (ie T = 10 , T =20 , T = 30.) The T does not have to exactly 10, but close. Continue this process until the soldering reaches its maximum temperature and the temperature is no longer rising. If things begin to move to fast remove the soldering gun from the upper heat sink and allow the system to cool for a few moments and get caught up with your measurements.
  10. Plot a graph of Voltage VS. Temperature using graphing software recommended by your instructor.

Data:

Datum / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10
Upper Temp
Lower Temp
T
Voltage
Datum / 11 / 12 / 13 / 14 / 15 / 16 / 17 / 18 / 19 / 20
Upper Temp
Lower Temp
T
Voltage