SAVANNAH, Ga. (WSAV) – An anemometer is a device that measures wind speed! Meteorologists use this device during strong storms to see how strong the wind is. You can also find one on our Storm Tracker!
When I travel to school visits, I take our handheld anemometer with me. I ask the students if they “think they are stronger than a hurricane” (occasionally I get a yes haha!). I then make them blow into the anemometer to see how fast they can get “their wind” up to. The highest so far has been 40 mph. That’s tropical storm strength!
HOW TO MAKE YOUR OWN ANEMOMETER:
2 Straws (or popsicle sticks)
1 Pencil with Unused Eraser
Ruler (if you have one)
This is where you can decorate your anemometer if you would like!
MAKING HOLES IN THE CUPS:
1. Take 4 of the cups and punch one hole on the side of the cup, 1/2″ below the rim on each cup.
2. Take the 5th cup (center cup) and punch 2 holes directly across from each other, 1/2″ below the rim.
3. Also on the 5th cup, punch 2 more holes 1/4″ below the rim, directly opposite of the other. The holes should be equally spaced between the first 2 holes.
— There should be 4 equally spaced holes near the center of the cup. (It’s okay if they aren’t perfectly spaced…mine definitely wasn’t!)
4. Take the 5th cup and use a pushpin to make a hole on the bottom. Then, take scissors to make the hole bigger. This hole needs to be large enough to fit the pencil.
CONNECTING THE ANEMOMETER PARTS:
5. Slide 1 straw through one of the 1 hole-punched cups. Bend 1/2″ of the straw’s end and tape to the inside of the cup.
–Repeat step 5 with the other straw and another 1 hole punched cup.
6. Feed the taped straw from one of the cups through the center cup (the one with 4 holes). Make sure you push the straw through the holes that are directly across from each other.
–1 hole punched cups should be on their side. The 4 hole punched cup should be sitting straight up.
7. Slide the rest of the straw through another 1-hole punched cup and tape the end of the straw to the side of the cup.
–Repeat step 6 & 7 with the other straw attached to the other 1 hole punched cup.
IMPORTANT: Make sure the openings of cups 1 – 4 are all facing the same way. All 4 cups should be sideways.
8. Push the eraser side of the pencil through the opening on the bottom of the center cup.
9. Push the pencil upward until it meets the intersecting straws.
10. Push the pushpin through the intersecting straws and into the eraser.
–Don’t push the pin in as tight as it will go…otherwise the anemometer won’t spin when exposed to the wind.
WHY DOES THE WIND BLOW?
As the sun heats up gases and air particles in the atmosphere, those particles and gases will move from high to low pressure. Winds spin clock wise around high pressure and counter-clockwise around low pressure.
But what causes the air to flow from high to low pressure… it is actually differences in temperature!
WHAT CREATES WIND?
When the sun warms the air particles, the molecules begin to move apart and move faster. When air particles cool down, the molecules slow down and get close together. Warm air rises because it weighs more than cold air. The cooler air then moves in and sinks. Think of a slide… you have to climb stairs to get to the top that is warm air rising…and then go down the slide by sinking…as the cold air.
The sun doesn’t warm up the earth’s surface evenly… This leads to different areas of warm and cold air.
Go back to the slide analogy…. you have to climb the stairs to get to the high pressure…and then sink down to the low pressure….just like how warm air rises and cold air sinks. The bigger the difference between the pressures and the temperatures, the faster the air will move aka…the faster the wind the blow.