Home-Made Anemometer: A Weather and Wind Activity

Anemometer

An anemometer is an instrument used to measure the speed of wind. It can easily be made with a few objects that you probably already have sitting around in your home right now. You could use it in conjunction with the weather vane activity, to measure both the speed and direction of wind.

You will need:

• 5 plastic or paper cups
• 3 wooden dowels or skewers
• plastic water bottle
• tape or glue
• hole punch

First, you will need to punch one hole in four of the cups. Punch four evenly spaced holes in the final cup. Place two of the dowels or skewers into the top of the cup with the four holes, forming an x over the top. Tape or glue the skewers or dowels together. Place the other four cups onto the ends of the skewers ensuring that all of the cups are facing the same direction. Tape or glue them into place. Poke the final skewer or dowel through the bottom of the cup in the center. Secure that dowel or skewer to the intersection of the other two. Finally, place the other end of the skewer or dial into the empty water bottle. Congratulations, you just made an anemometer.

To use the anemometer, first set a timer. Then count the number of rotations that ocures in that time frame. The faster the wind is, the more rotations you will count.

To make the anemometer easier to use, draw a small object (such as a heart, a star, or even just an x) on one of the outer cups. Now, to count rotations, you simply need to count how many times the object whirls by.

If you want to know how many miles per hour the wind is blowing, you will need to calibrate your anemometer. Have someone drive you around a parking lot at ten miles per hour. Hold your anemometer out the window for sixty seconds. Count the number of rotations. Now you know how many rotations per minute occur at sixty miles per hour. Let's say you measured 50 rotations per minute at ten mph, and you measured the current wind speed at 100 rotations. You can divide the number of rotations at 10 mph by the number of rotations that you just measured. You will get two. The wind is twice as fast as it is at ten mph, therefore it is currently 20 mph. Because of the math involved, I would only recommend bothering to calibrate your anemometer with students in middle school or above.

Bring your little student outside. Bring their attention to the wind. Ask them what they notice. Is the wind blowing stronger or weaker now? Take out the anemometer. Count the rotations, also have them note how the wind subjectively felt at that moment. Wait a little while and try again. Was the wind stronger or weaker the second time? Did the anemometer have more or fewer rotations?

This activity was a lot of fun. We used it on a very gusty day. She squealed with glee when the anemometer began to spin more quickly.

You May Also Enjoy:

• Weathervane
• Straw Flute: A Handmade Instrument
• Found Object Wind Chime
• Wind Painting
• Bottle Cap Sail Boats
• Book Round Up: Wind