======Make a Barometer======


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**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
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**Categories:** {{$demo.categories}}
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**Alternative titles:** Balloon Jar Barometer
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====Summary====                   
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====Procedure====  
  - Cut the neck off a balloon and stretch the remaining part tightly over the opening of a jar.  
  - Secure the balloon in place with a thick elastic band to create a sealed surface.  
  - Cut one end of a straw at an angle to make a pointer.  
  - Tape the straw flat to the center of the stretched balloon so that the pointed end sticks out.  
  - Place a sheet of paper or card behind the straw and mark a baseline where the pointer rests. Add weather symbols like a sun at the top and a cloud at the bottom for reference.  
  - Observe how the straw moves over time as changes in air pressure push the balloon up or down.



====Links==== 
Making a Barometer! - Clayton’s Exploration Station: 
{{youtube>9JHuXRTSxx8?}}\\

How to make a Barometer | DIY Science Time - learningscienceisfun
: 
{{youtube>oeXYRKqL0yM?}}\\

📄 How to make a Barometer - Housing a Forest: [[http://www.housingaforest.com/how-to-make-a-barometer/]]\\


====Variations====
  * Use a larger jar for a bigger surface area. 
  * Keep a weather journal alongside the barometer to compare readings with actual weather reports.



====Safety Precautions====
  * Scissors should be handled carefully when cutting the balloon and straw.  
  * Ensure the jar is glass or sturdy plastic; avoid rough handling to prevent breakage.  
  * Supervise young children when assembling the barometer.




====Questions to Consider====
  * Why does the straw move up or down when the weather changes? (Changes in air pressure push the balloon surface, which moves the straw.)  
  * How might the readings differ on a rainy day compared to a sunny day? (Rainy days often have lower air pressure; sunny days often have higher air pressure.)  
  * What other instruments do meteorologists use to study weather? (Thermometers, rain gauges, wind vanes, anemometers, etc.)  
  * Could this barometer also be used to measure altitude? (In principle, yes, since altitude changes affect air pressure, though a homemade version may not be precise enough.)