Science Buddies: "Ask an Expert"

I have a question on the experiment "Seebeck Effect: Turning Heat Into Electricity and Measuring It with a Thermocouple Thermometer" When I am reading hot temperatures with the thermocouple wire, why does the multimeter have a negative reading? When I am reading cold temperatures with the thermocouple wire, I have a positive reading on the multimeter. Why is this? Why do hot objects such as boiling water have a negative multimeter reading and cold objects such as ice cold water have a positive multimeter reading? Please answer this question. Thank you!

Hi danobb77,

You might try reversing the polarity of the thermocouple connection to the multimeter. To do this just swap the connections at the meter. Plug the wire that's in the black (or COM) socket into the red or (+) socket. And plug the wire that's in the red (+) socket into the black (COM) socket.

I hope this helps. Please ask again if you have more questions.

A. Norman