Each student can make their own barometer to take home to show to parents and describe how it works. They should bring back a signed form from home that says the student described the barometer and how it works to the people at home. Have students complete their models by sticking dots on their pieces of paper. A barometer has a piece of special metal in it called corrugated metal that squeezes down when heavier air pushes on it and expands up when lighter air does not push so much on it. There is a needle attached to the metal that points to a number on the dial to tell the air pressure.
Lower numbers indicate low pressure and higher numbers indicate high pressure.
Air pressures usually range from 29.00 to 31.00 inches in Nebraska. The number tells how many pounds of pressure the air is pushing down with on every square inch at that time. For example, a barometer reading of 29.5 means that the air is pushing down with 29.5 pounds of force on every square inch of stuff it touches. Think about someone stepping on your foot with a tennis shoe. The flat sole of the shoe evenly distributes the weight of the person over your whole foot and it doesn t hurt too much.