Junior Cycle Geography CYCLONE CBA 2 My Geography Moment
MAKE YOUR OWN WEATHER INSTRUMENTS Make Your Own Barometer
You will need: Tape Straw
Rubber band
Jar Scissors Needle Balloon
Drinking straw moving up or down depending on outside air pressure
5 4 1 2
Rubber 'skin' from balloon
Low
Pressure System
Air pressure inside jar is lower than outside
Stiff card Glass jar 3 Pencil Glue
Marker pen
Card
High
Pressure System
Air pressure inside jar is higher than outside
1 Cut the neck off the balloon and stretch the main piece (the ‘balloon’ part) over the opening of the glass jar − the tighter the better. (Make sure the balloon has not been blown up at any point.)
2 Stretch the rubber band around the balloon and opening of the jar to hold the balloon in place and to seal it, so no air can get in or out.
3 Glue a needle to one end of the straight straw (do not use a bendy straw, or cut the bendy piece off the straw and use the remaining straight piece). This will act as your pointer.
4 Glue the other end of the straw to the centre of the balloon covering and gently tape in place until the glue has dried and holds the straw in place itself.
5 Place your barometer beside a wall and tape a piece of card to the wall at the point that the needle hits. On the card, write ‘High’ above and ‘Low’ under the needle’s point. Use a pencil or pen to record the atmospheric pressure three times a day: in the morning, at lunchtime and at the end of the school day.