Perfect for a science project or home activity, making your own barometer is simple and a lot of fun. You can build a simple aneroid barometer (relative to 'air') using a balloon, a pot, and some other basic utensils. Alternatively, you can assemble a water barometer using a bottle, some plastic tubes, and a ruler. Regardless of your choice, the barometer will help you analyze atmospheric pressure - one of the measurements taken by meteorologists to make accurate predictions.
Method 1 of 2: Making an Aneroid Barometer
Step 1. Cut off the tip of a bladder
With scissors, cut off the end of the bladder - there is no exact spot. Just try to get an opening big enough to cover the entire mouth of the pot.
Step 2. Stretch the bladder over the top of the pot
Use your hands to pull the mouth of the bladder and place it in the neck of the pot. Pull it to cover it completely, without any wrinkles.
- When the bladder is fully stretched in the mouth of the pot, place a rubber band over the rim to hold it in place.
- The glass pot is the best option, but you can also use something made of metal.
- Whether you want to use a pot or a can, the exact size doesn't exist. The most important thing is that the mouth is not so big that the bladder cannot easily cover it.
Step 3. Glue the straw over the pot
If present, cut off the bent end. Put a small amount of glue on one end and position it so that one end touches the center of the bladder. The rest of the straw should rest on the edge of the pot. It will work as a pointer, giving you the ability to record variations in atmospheric pressure.
- Silicone glue also works well. You can use super glue, craft glue or even glue stick if needed.
- Remember to let the glue dry before proceeding.
- The longer the straw, the better (provided it is straight). You can even stick the end of one straw into another to make a longer one.
Step 4. Add a pointer
You can glue a needle to the other end of the straw, leaving the sharp side out. If you want something less sharp, cut a small arrow from cardboard or cardboard and insert it into the hollow end of the straw. Keep it snug so it doesn't fall out. It will display how much the straw moves up and down during changes in pressure.
Step 5. Place some stiff paper next to the pointer
To make everything simple and effective, glue a sheet of paper to a wall and place the pot on its side so that the pointer is facing you. Mark your position on the paper, noting "high" above and "low" below the mark.
- Rigid papers such as cardboard or cardboard more easily stay in the same position, but you can also use plain paper in the absence of any other option. You'll find several varieties at stores that sell school or office supplies.
- The pointer should be close to the paper, but not touching it.
Step 6. Record changes in pointer position
As the pressure rises, it will rise. In times of fall, in turn, it will also fall. Watch the magic happen and mark when you notice that the pointer has changed its position.
- If you like, you can label the start position as "
Step 1." and number each new measurement in ascending order. This is a great idea if you want to use the barometer in a science experiment.
- The barometer works well because high air pressure pushes the bladder down, raising the needle, and vice versa.
Step 7. Interpret the results
Note the weather conditions associated with each change in barometer position. When it rises at high blood pressure, does it indicate that the sky is clear or cloudy? And when it drops because of the drop in pressure?
Low blood pressure is often associated with rainy weather, while high blood pressure can indicate mild or cool weather
Method 2 of 2: Making a Water Barometer
Step 1. Cut off the top of a plastic bottle
Ordinary two-liter PET bottles serve this experiment very well - get one that is already clean and empty. Take a pair of scissors and carefully cut the entire top section, reaching the point where the sides go from curved to straight.
Step 2. Place a ruler inside the bottle, leaving it standing on the edge
Use a piece of duct tape on the outside of the bottle and part of the ruler to keep everything in place - the measurement numbers must remain visible.
Step 3. Thread a clean tube
It should arrive just before the base of the bottle. Secure it in place against the edge. It is best to apply masking tape over water as water can soften it and cause it to fall out.
- You will probably need 40 centimeters of tube coming out of the top of the bottle. If it's not long enough, cut the edges of the bottle to make them lower.
- Leave some of the tube loose.
Step 4. Leave the water in your favorite color and pour in a certain amount
You will need to have enough water to fill the bottle halfway. Apply a few drops of your favorite food coloring to make everything more special.
Step 5. Draw some water into the tube
Use the loose end like a straw and gently pull some of the water up. Raise it halfway up the tube - as it's already been dyed, the water will be quite visible.
- Place your tongue over the tip of the tube when the water is in place to maintain suction and prevent it from flowing back down.
- Be careful not to draw water all the way!
Step 6. Seal the tube with something sticky
You can use a sticker or even a piece of (used) gum! Take a piece while your tongue is still on the tube. Quickly remove it and immediately put it in place. This will help keep the pressure and water in place.
You have to be fast to do the right thing! If you get it wrong, try again
Step 7. Mark the water line on the outside of the bottle
When the air pressure rises, the water level will go down in the bottle and up in the tube. When the pressure drops, the water will rise in the bottle and go down into the tube.
You can also mark the various positions on the ruler if you like, or measure how much water has risen or fallen
Step 8. Study the data obtained
The water in the tube will rise on clear days and fall on cloudy or rainy days. However, if you keep a good track record with the barometer, you'll find that variations in pressure also manifest without major changes in weather.
Since the aquatic barometer has a ruler, you can also record pressure changes as exact changes in centimeters or millimeters. Use this facility to notice even the smallest variations
- Always supervise children using scissors and needles as these are sharp objects.
- Bladders pose a risk of suffocation and should not be used by young children without adult supervision.