How To Make a Barometer

A barometer is a instrument to measure pressure changes in the atmosphere.  It is used to help forecast short term weather events.

I made a Barometer in a few simple steps:

First you will need the following:

glass jar
balloon
rubber band
pair of scissors
straw
tape

To assemble the barometer:

1. Cover the top of your jar with a balloon. You want to create an airtight seal and a smooth surface.
2. Secure the balloon with a rubber band. The most important part of making the barometer is getting a good seal around the rim of the container.
3. Lay the straw over the top of the wrapped container so that about two-thirds of the straw is over the opening.
4. Secure the straw with a piece of tape.
5. Either tape an index card to the back of the container or else set up your barometer with a sheet of notebook paper behind it.
6. Record the location of the straw on your card or paper.
7. Over time the straw will move up and down in response to changes in air pressure. Watch the movement of the straw and record the new readings.

Make Your Own!!!! (link to a youtube video for even more barometer fun)

The barometer I made did not seem to waiver a great deal on a daily basis but days where I noticed pressure change without the barometer I could take a measurement and see a more significant change.  Over time I noticed the stress of the balloon stretching which may affect the reasonable value for daily changes.  The balloon over time would need to be changed at some point in time.