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How to Make a Barometer at Home

Snehal Motkar Mar 17, 2019
Have you been asked to make a barometer as your science project at school? If yes, this post is worth reading to make your project successful.
A barometer, by definition, is an instrument used to measure atmospheric pressure especially for weather forecast and determination of altitude. Using these measurements, meteorologists are also able to predict sudden storms or any unusual weather patterns.
Though a barometer is an important device used by meteorologists or professional weather forecasters, it is a fairly simple device that you can make at home too.

Making a Water Barometer

Just like an atmospheric barometer, you can even use a water barometer to measure air pressure. In fact, a water barometer is the oldest form and the modern mercury barometers are based on the same design.
The changes in measurements on the scale of water barometer determine the changes in the weather and these changes are visible when the water in the straw rises or falls (higher the water level, lower is the atmospheric pressure). Following are some easy instructions to make a water barometer at home.

You will Need

  • Glass jar
  • Tape
  • Ruler
  • A transparent straw
  • A pencil and a piece of paper
  • Chewing gum


Step 1
Take the glass jar and fill it halfway with water.

Step 2
Take a ruler and tape it on the wall near which you intend to keep the jar. Place the jar near the wall such that you can record the measurements conveniently.
Step 3
Now, insert the transparent straw in water and suck a few inches of water. Then, chew a gum and cover the top of the straw with it. If you are taking the straw out while sealing it, make sure you place the straw back in water with at least an inch of the straw below water. Also, let the water level in the straw be higher than that in the jar.
Step 4
Fix the straw with an airtight seal, so that you can record the measurements with ease. Note the current position of water level in the straw, on a piece of paper. Record the measurement, i.e. the level of water in the straw, at least once a day to know the air pressure.

How to Make a Balloon Barometer

A balloon barometer can be made with household equipment to record changes in atmospheric pressure. The straw taped on the balloon with a pencil attached on the other side, marks the measurements on the scale. When the pencil marks on the lower side of the scale it indicates low pressure, indicating that the weather is going to be a little rough and stormy.
Whereas the rise in the measurements indicate high pressure meaning fair weather. After knowing about the working of this barometer, you might be wondering about the availability of required materials and the overall expense in making a barometer. Most of the required materials are available in the house or at the local store.

You will Need

  • A glass jar or an empty tin (wide opening)
  • A sufficiently large balloon
  • Rubber band
  • Scissors
  • Pencil
  • Plastic straw
  • Ruler


Step 1
Blow the balloon to stretch it and release to let the air out completely.

Step 2
Cut the balloon through the middle to obtain two parts. You will need only the round portion of the balloon so discard the neck part.
Step 3
Spread the balloon over the mouth of the glass jar (assuming that you have a glass jar) and seal it with the rubber band. Make sure that air does not pass into the jar because it can affect the readings.
Step 4
Now, take the straw and tape it at the center of the balloon. You will see some part of the straw outside the jar at a particular distance from the ground.

Step 5
Take a ruler and tape it on the wall and keep the glass jar closer to the wall such that the straw touches the middle of the ruler giving the straw enough room for movement.
Step 6
Mark the current position of the straw and wait till the next day. On the second day, check the position of the straw again. If it rises above the previous position, the weather is clear and if it drops in position, it indicates cloudy weather and possibility of rain.
These were two simple ways to create your own barometer and understand the working of a barometer. Apart from fun, it will also be a knowledgeable task for you. When the atmospheric pressure is low, i.e., your scale shows lower measurements you can predict a rough weather and possibility of a storm.
On the other hand when measurements are of higher value it means the weather will be clear. Imagine making your own forecasts and sounding like an expert or a meteorologist.