Thermometers

Today, we spent some time learning about thermometers.  We did a really cool and easy experiment to demonstrate how a basic bulb thermometer works. 

I checked out this book from the library so we could get a better understanding of the history of thermometers and how they work.  We also took the opportunity to learn a little more about Galileo.

We examined all of the thermometers that I could find in our house.  Surprisingly, we have a few different types.

A meat thermometer.

A digital thermometer.

This type of thermometer is based on Galileo's thermoscope.  The temperature was around 74 in our house so we thought we would put it outside for about 20 minutes to see how the temperature would change.  After  the 20 minutes, the temperature went up to 84.  Then, just for fun, we  put the thermometer in the refrigerator for 20 minutes and the temperature cooled off to around 68.  This is called a "Slow thermometer" so it does take a little time to see a change.  This is also really neat and decorative thermometer.

This is our outside thermometer.  Holy COW!  It is measuring a temperature around 107.  It was actually around 95 but since this thermometer sits in the sun, it made the reading go up.  It did feel like 107 though.

We decided to try our hand at making a simple replica of a bulb thermometer.

What you need to have and do:

A glass jar with a lid that you can make a hole in for a straw.

A straw and some food coloring.  You can do it without food coloring but it is easier to see with it.

You need some type of putty or a piece of chewing gum to seal around the hole in your lid and the straw.

Ice cold water.  You will need to fill the jar almost to the top but strain the ice out first.

After you fill the jar with the water, add the food coloring if you are using it.

Put the top on and seal around the straw.

Place the jar in really HOT water and watch.  We decided to make 3 minute checks.  This is after the first 3 minutes.  As you can see, the colored water is beginning to rise up the straw.

After about 6 minutes, you can see how much the colored water has moved up the straw.

This is after 9 minutes.

And at 12 minutes, the water was coming out of the end of the straw.

We also noted that when the hot water in the bowl started to cool down, the colored water in the straw went back down into the jar as seen in the next 2 pictures.

Going back down.

Down, down, down!   Eventually, the straw was empty.

We read various books about thermometers and my kids did a notebooking page with an illustration on some of the things they learned. (Below)
 

So that is it for thermometers.  We really learned a lot of information, and we had fun doing it.