Anemometer

Camp-in-a-Box 2021

Scientists use many different types of instruments to measure many different things. Scales for measuring weight and thermometers for temperature are two examples you’ve seen before.  Scientists who study things like the environment, the oceans, and the weather use an instrument called an anemometer that measures the speed of the wind.

For this activity, you need:
5 small paper cups
2 straws
A new pencil
A bag of air dry clay
A sewing pin or push pin
Tape
Sharpie or markers
A good pair of scissors

  1. On one of your cups, draw four dots just below the rim of the cup.  These dots should be evenly spaced so they are on opposite sides of the cup from each other.  Draw another dot in the middle of the bottom of the cup.
  2. Using your sharp scissors, carefully punch holes where your dots are.
  3. Thread one of the straws through a pair of upper holes.  Thread the other straw through the other pair.
  4. Thread a cup on to the end of each straw. Use pieces of tape to secure the straw in place so the cup can’t slide back off.  As you work, make sure the cups are all facing in the same direction. Think of all the horses facing forward as a merry-go-round spins.
  5. Slide your pencil up through the hole in the center of your middle cup.  Carefully push your pin through the two straws and then into the eraser of the pencil.
  6. Next, make a stand for your anemometer.  Mold the air dry clay around the base of the pencil.  You are hoping for a wide base with a tall section around the pencil.  Once you have a shape you like, wiggle the pencil around a bit to make the hole a little wider.  While gently turning the pencil, pull the pencil back out and set your stand aside to dry.  This can take several days.

    Note: Once the clay dries, the pencil should be able to spin freely in the stand.
    If you find your air dry clay stand is too short or too light, you can also use an empty water bottle.  Partly fill the bottle with sand or pebbles to add some weight.

You can use your anemometer to tell how fast the wind is blowing!  How?

  • Use your markers to color one of the cups a bright color, something you can spot really well as the anemometer turns.
  • When the anemometer is spinning in the wind, count how many times that cup goes by in 10 seconds.
  • Use this chart to find roughly how fast the wind is blowing.

This chart is from WindAndWeatherTools.com