If you look at this thermometer you'll notice that it has an unusual scale. We get used to thermometers going up to 100 degrees Celsius but why would you if it is being used in a fridge? It's a good example of adjusting the range to fit the data. It means that we can keep the scale divisions worth 1 degree Celsius. It is a rotary thermometer. I'm guessing that it contains a coiled bimetallic strip which uncoils as it warms and expands, thus moving the needle round the scale.
