Thermodynamics Optional Topic 1

Errors and Calibration of Thermometers

Label several thermometers so they are distinguishable. Put the thermometers in ice water and wait until the reported temperatures stabilize. This may take a few minutes. Record the label and temperature as reported by each thermometer. NOTE: The temperatures should be different enough that the difference is obvious. Do this experiment in advance to make sure they are different.

Put the thermometers into boiling water and wait until the reported temperatures stabilize. Again, record the temperatures and associated labels.

Make batches of water at at least two more distinct temperatures. Repeat the measurements as before.

Encourage the students to think about the fact that the thermometers do not report the same temperature. Have them outline all the issues, implications, and solutions they can concerning this situation.

The students' outlines should consider some or all of the following. What are the implications in measureing temperatures? Can such problems be overcome? Is this a statistical problem or a systematic problem? That is, can such errors be removed by a careful calibration or are the errors random? How important is the problem? How do we decide when it is important? Are there other experiments we can perform to characterize the problem? Anything else the students consider is also good.