- Wire up the op amp circuit and construct the thermocouples.
- Null-out the circuit by adjusting the potentiometer to make the voltmeter (connected to op amp pin 6) read zero.
- Connect the voltmeter to the left end of the 1k resistor, and set it for the most sensitive range.
- What voltage do you get? ____________
- With the torch set on very low flame, and with the torch
three or four inches from the junction, heat up junction 1
slightly.
- What voltage do you get? ____________
- Connect the voltmeter to op amp pin 6 and leave it there for the rest of the experiment.
- Heat up junction 1 again.
- What voltage do you get? ____________
- Move junction 1 and junction 2 so that they're physically close to each other.
- Heat up both junctions evenly.
- What voltage do you get? ____________
- Move the junctions so they're far apart, and blow on junction 2 to cool it down.
- What voltage do you get? ____________
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