How to Build a Barometer
Gather your materials., Cut the end off the rubber balloon., Stretch the rubber balloon tightly around the mouth of the container., Cut a small arrow out of construction paper to attach to the straw., Glue two straws or coffee stirrers together...
Step-by-Step Guide
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Step 1: Gather your materials.
To make a tin can barometer, you will need a tin can, a balloon, a rubber band, glue, two plastic straws or coffee stirrers, construction paper, and an index card.Most of these items should be easily found around the home.
If you don’t have a tin can, any container with a large-mouth (diameter of
1.5
-2 inches), plastic or glass, will work for this barometer.
A bottle with a narrow mouth will not work.
A rubber or latex glove will also work in place of a balloon. -
Step 2: Cut the end off the rubber balloon.
You will use the balloon (or glove) to cover the mouth of your container.
In order to get a piece that will stretch over the mouth, you must first cut the end off the balloon.
Snip off the entire straight/narrow part of the balloon, just below where the round part of the balloon begins.If you are using a rubber glove, cut off the fingers of the glove and cut the glove down one of the sides so you have a flat piece of glove that can cover the entire mouth of your container. , Slide the balloon onto the wide-mouthed bottle or jar so that it is stretched completely flat across the mouth of the container.
Secure the balloon in place with a rubber band around the sides.
Ensure the seal is tight around the rubber band and that no air is leaking into or out of the container., Draw and cut out an arrow small enough to fit into the end of the straw.
Alternatively, if you are using a coffee stirrer, cut it small enough to glue onto the end of the stirrer.
This arrow will help you determine the relative pressure more accurately. , The more length of arm that extends past the edge of the container, the more accurate your relative pressure readings will be.
To extend the length of the arm, stick one straw inside another and glue or tape them together.
If you are using coffee stirrers, simply glue or tape two of them together.
Make sure the arm is still straight and doesn’t bend at the join between the two pieces.
Use sticks which are very light (drinking straws are perfect for this project) so that the weight of the stick does not cause the rubber to stretch. , Place a small dab of white craft glue in the center of the balloon and place the end without the arrow into the glue.
Place a small piece of tape over the arm to hold the straw in place while the glue sets.
After the glue is dry, you can remove the tape. , Make a mark in the middle of the card where the arm points when it is directly horizontal.
Above the middle line, draw an arrow pointing up and write “High Pressure”.
Below the middle line, draw an arrow pointing down and write “Low Pressure”.
When the arm points toward “High Pressure”, the weather is usually sunny with clear skies.
When the arm points toward “Low Pressure”, the weather is likely cloudy and/or rainy.
Tape the index card to the wall next to the barometer. , Place the barometer in a place away from activity where no one can knock it over.
Arrange it so that the end of the arm points horizontally at the center of the index card weather gauge. , When the pressure increases, the balloon over the can will deflate.
This will cause the arm to point up towards “High Pressure”.
When air pressure decreases, the balloon will inflate causing the arm to point down towards “Low Pressure”.Although this barometer cannot tell you the exact air pressure, you will still be able to determine the relative air pressure and predict the weather outside! -
Step 3: Stretch the rubber balloon tightly around the mouth of the container.
-
Step 4: Cut a small arrow out of construction paper to attach to the straw.
-
Step 5: Glue two straws or coffee stirrers together.
-
Step 6: Glue the straw or coffee stirrer arm to the middle of the balloon.
-
Step 7: Label the index card with a weather gauge.
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Step 8: Arrange the barometer so that the arrow points to the weather gauge index card.
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Step 9: Observe the pressure changes from your barometer.
Detailed Guide
To make a tin can barometer, you will need a tin can, a balloon, a rubber band, glue, two plastic straws or coffee stirrers, construction paper, and an index card.Most of these items should be easily found around the home.
If you don’t have a tin can, any container with a large-mouth (diameter of
1.5
-2 inches), plastic or glass, will work for this barometer.
A bottle with a narrow mouth will not work.
A rubber or latex glove will also work in place of a balloon.
You will use the balloon (or glove) to cover the mouth of your container.
In order to get a piece that will stretch over the mouth, you must first cut the end off the balloon.
Snip off the entire straight/narrow part of the balloon, just below where the round part of the balloon begins.If you are using a rubber glove, cut off the fingers of the glove and cut the glove down one of the sides so you have a flat piece of glove that can cover the entire mouth of your container. , Slide the balloon onto the wide-mouthed bottle or jar so that it is stretched completely flat across the mouth of the container.
Secure the balloon in place with a rubber band around the sides.
Ensure the seal is tight around the rubber band and that no air is leaking into or out of the container., Draw and cut out an arrow small enough to fit into the end of the straw.
Alternatively, if you are using a coffee stirrer, cut it small enough to glue onto the end of the stirrer.
This arrow will help you determine the relative pressure more accurately. , The more length of arm that extends past the edge of the container, the more accurate your relative pressure readings will be.
To extend the length of the arm, stick one straw inside another and glue or tape them together.
If you are using coffee stirrers, simply glue or tape two of them together.
Make sure the arm is still straight and doesn’t bend at the join between the two pieces.
Use sticks which are very light (drinking straws are perfect for this project) so that the weight of the stick does not cause the rubber to stretch. , Place a small dab of white craft glue in the center of the balloon and place the end without the arrow into the glue.
Place a small piece of tape over the arm to hold the straw in place while the glue sets.
After the glue is dry, you can remove the tape. , Make a mark in the middle of the card where the arm points when it is directly horizontal.
Above the middle line, draw an arrow pointing up and write “High Pressure”.
Below the middle line, draw an arrow pointing down and write “Low Pressure”.
When the arm points toward “High Pressure”, the weather is usually sunny with clear skies.
When the arm points toward “Low Pressure”, the weather is likely cloudy and/or rainy.
Tape the index card to the wall next to the barometer. , Place the barometer in a place away from activity where no one can knock it over.
Arrange it so that the end of the arm points horizontally at the center of the index card weather gauge. , When the pressure increases, the balloon over the can will deflate.
This will cause the arm to point up towards “High Pressure”.
When air pressure decreases, the balloon will inflate causing the arm to point down towards “Low Pressure”.Although this barometer cannot tell you the exact air pressure, you will still be able to determine the relative air pressure and predict the weather outside!
About the Author
Charles Adams
Writer and educator with a focus on practical practical skills knowledge.
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