Build a Barometer

• Use an empty coffee can, plastic wrap, large rubber band, pin, glue, straw and index card to have students build their own barometer to measure changes in air pressure. Stretch the plastic wrap over the top of the coffee can. Use the rubber band to hold the plastic securely in place. Ensure it is tight or it won't work properly. Lay the straw against the plastic wrap with two-thirds of the straw on the plastic and the other edge hanging over. Tape the straw down firmly on the plastic to keep it in place. Attach the pin to the end of the overhanging straw, with the pin facing down. Draw evenly spaced lines on the index card and secure it to the can underneath the straw. As the air pressure increases the plastic expands or contracts, lifting the straw and the pin and moving it's location on the index card. Have students record the changes.
  
  

Temperature and Air Pressure Experiment

• Have students use their barometer in experiments to understand the relationship between temperature and air pressure. Have them note the position of the pin on the index card at room temperature. Next, instruct the student to gently wrap her hands around the coffee can part of the barometer. Wait ten minutes and check the position of the pin again. The student's hands heat up the coffee can causing the air pressure in the can to increase. This makes the pin move up on the index card.
  
  

Weather and Air Pressure Experiment

• Send your students home with their barometers to conduct a week-long experiment on weather and air pressure. Have students make three recordings with their barometer a day. Students must note the weather at the times of the readings. At the end of the week, students compare their recordings with the weather changes to understand how the changes in air pressure coincide with the changes in weather, such as how the air pressure drops just before a storm.
  
  

Altitude and Air Pressure Experiment

• For students' final experiment, have them observe the changes in air pressure as they change altitude. Take your class on a field trip to a hill with a 1,000 feet elevation or up a ten story building with an elevator. Students will take a barometer reading at the base of the building or hill and then repeat this at the top of the hill or building. This teaches them the changes in air pressure that occur with the changes in altitude.