Make a Barometer
This activity will give students an opportunity to make their own
barometer and to observe changes in the local weather.
Time requirement: 40 minutes as an activity, 20 minutes as a demonstration.
- 1 container about the size of a soup can
- 1 balloon or other latex material large enough to slip over top of
- 1 popsicle stick
- 1 3x5 index card
- 1 pencil
- Masking tape
- Stretch the balloon tightly over the top of the container. Make sure
that the container is at room temperature.
- Tape the edges of the balloon to the side of the container making an
- Place a drop of glue onto the middle of the balloon and glue one end
of the popsicle stick there. Allow the other end of the stick to extend
over the edge of the container. Allow the glue to dry.
- Stand the 3x5 card on end (or attach the card to the side of the
container) next to the end of the stick which extends over the edge of
the container. Mark the position of the stick on the card.
- As the air pressure changes, the stick will respond by moving up or
down relative to the original mark.
- Make observations of the air pressure for a number of days by
marking the position of the stick each day. Correlate the position
of the stick with readings from a calibrated barometer or with weather
data from a local newspaper.
- Temperature changes will also cause the stick to move, so be sure
that the room temperature is constant with each observation.
- Does the stick move up or down with an increase in air pressure?
- What happens to the balloon with an increase in air pressure?
- Why does the stick move in the other direction with a decrease in
- Why is the room temperature so important to this activity? What
happens to the stick if the room temperature changes?
- Will the barometer work if the balloon is not sealed air-tight?
To think about
If you have ever driven into the mountains with a sealed bag of food,
you will surely have noticed that the bag expands like a balloon at
high altitude. Why does this happen? What would happen if you brought
your home-made barometer to high altitude???
Last updated: August 26, 1997
Joe Twicken /