How to Make a Homemade Barometer

Making your own barometer at home can be an ideal science project for not only young learners, but any and all adult weather geeks. Luckily, charting changes in air pressure is a fairly simple task. A makeshift barometer can be constructed out of various materials lying about the house.

Difficulty: Easy

Instructions

Things You'll Need:

• Balloon
• Can/jar
• Rubber band
• Straw
• Tape
• Piece of paper

1. Cut a balloon in half. Discard the half with the neck.

2. Stretch the remaining portion of the balloon over the top of a small can or jar, to form a lid. Hold the balloon in place with a rubber band, making as airtight a seal as possible.

3. Attach one end of a straw firmly to the jar's new 'lid,' with tape. One-quarter of the straw should sit on the lid itself, while the other 3/4 should hang off into space.

4. Place the jar next to a piece of paper, with the straw running parallel to the paper.

5. Mark the position of the straw against the paper each day. A straw that lowers indicates dropping air pressure, which may be a sign of coming clouds of rain, and a straw that rises may be a sign of sunnier days. Match the actual weather to your readings, to find patterns.

Tips & Warnings

• Try to mark the position at the same time each day, and when the temperature is approximately the same. Hot or cool temperatures can cause air to expand or contract, changing the reading.
• Try not to leave your barometer in direct sunlight, as this can cause wear to the balloon.