Make and Use an Anemometer to measure Wind
Wind is the horizontal movement of air. The instrument used to measure
wind speed is called an anemometer, which is an indicator that will spin in the wind. The
anemometer rotates at the same speed as the wind. It gives a direct measure of
the speed of the wind. Wind speed is measured by using the
Beaufort Wind Scale
which is a scale of 0-12 based on visual clues. Depending
on the ability of students, it is probably sufficient that they recognize calm
air, and gentle, moderate, and strong breezes. For example, students can use a simplified scale such as the following:
||Smoke goes straight up
||Wind is felt on face;
weather vanes turn, leaves rustle
||Raises dust; flags flap
||Large branches move;
umbrellas turn inside out
|62 or more
||Gale / Whole Gale
Make an Anemometer
(if you already have an anemometer, you can skip to the
Use an Anemometer to measure Wind Speed)
- 4 small paper cups
- 4 plastic drinking straws
- straight pin
- pencil with a new eraser
- This anemometer has four cups which catch the wind and cause the
anemometer to spin. The inward curve of the cups receives most of the force
of the wind. That's what makes the cups move. The more spins per minute, the
greater the wind velocity.
- Arrange four (4) plastic drinking straws to form a cross and tape them
together at the center.
- Staple the top side of one drinking cup, such as the small paper cups designed for bathroom dispensers, to the end of each straw, so the open
ends of the cups all face the same direction.
- Push a straight pin through the center of the straws into an eraser on
the end of a pencil. This provides the axle.
- Mark one of the cups; this will be the one they use for counting when
the anemometer spins. NOTE: When using this anemometer, 10 turns per minute
means the wind speed is about one mile per hour. If possible, it would very
useful to use a commercial anemometer to determine an approximate
determination. For example, "when our anemometer read 20 spins a minute, the
commercial anemometer read 2 miles per hour."
- Blow on the anemometer or turn an electric fan on low to make sure that
it spins easily. How many times the anemometer will spin in one minute? Can
you make a statement connecting the number of spins of your anemometer and
the speed of the wind? (you can use the table below to record your
The photos below show the students from Mrs. Clarizio's
fourth grade class in Garfield, New Jersey making their anemometers. Click on
the picture to view a larger image.
||Number of Spins
Use an Anemometer to measure
- Divide the into small groups with the following roles (optional)
- One time keeper who will be responsible for timing one minute for each
- One official "counter" for the day. The others may count on their own,
but the counter's readings will be the ones recorded.
- One holder who will hold the anemometer while the spins are counted;
the holder should make sure that he holds the anemometer so that the wind
- Mount or hold the anemometer in a place that has full access to the wind
from all directions.
- When the time keeper says "Go", the counter in each group will count how
many times the marked cup passes them in one minute and write it down.
- If possible, repeat the above step four (4) times and record the average
number of spins
Optional: you can multiply the average number of spins by 60 to find
out how many times the anemometer would spin in an hour and come up with a
statement such as: the speed of the wind today is about 1,000 spins per
Copyright © 2007 Stevens Institute of Technology,
Center for Innovation in Engineering and Science Education (CIESE) All Rights Reserved.