Joe Chandler describes a homemade anemometer made from cups, straws, a pencil, and eraser. The anemometer works by catching wind in the cups which causes the structure to spin. Joe uses the anemometer to measure wind speeds over several days, recording the number of spins in 10 seconds and comparing to an online weather report. Wind speeds ranged from 1-10 mph during clear, cloudy, rainy, and stormy conditions.

1. By: Joe Chandler

2.  My anemometer is a pencil eraser and 5 cups. 4 of
the cups have holes in them with straws fed
through, the two cups opposite each other have
the same straw. All of the cups have holes and
where the straw is fed through it is bent and taped.
This way all of the cups openings are facing the
cup in front of its bottom. The straws in the cups
opposite each other are through the middle cup
with four holes in it. This middle cup has a pencil
through the bottom and a thumb tack is in the spot
where the straws intersect into the eraser. This is
the best I could explain it, sorry.

3.  The anemometer works because the
outside cups all face the same direction,
meaning that no matter which way the
wind is coming from it will be caught in one
of the cups. The wind in the cup moves the
whole straws and cups structure with the
thump tack acting as basically an axle. The
I count the rotations per 10 seconds.

4.  Spins in 10 seconds Wind Speed (MPH)
 2-4 1
 5-7 2
 8-9 3
 10-12 4
 13-15 5
 16-18 6
 19-21 7
 22-23 8 9
 24-26 9
 27-29 10
 30-32 11
 33-35 12
 36-37 13
 38-40 14
 41-43 15
 44-46 16
 47-49 17
 50-51 18
 52-54 19
 55-57 20

5.  On Sunday morning I measured the wind
speed with my anemometer. I got 5 spins in
the ten second that I timed. This means that
the wind speed was about 2 miles per hour.
There were no clouds in sight and it was
warm outside and just starting to get humid.
The wind was just a slight breeze. When I
looked on my Weather Channel App on my
phone which is set to Plymouth it said that the
wind speed was 3 miles an hour.

6. I measured the wind earlier than I wanted to
because a storm was moving in and I wanted
to see how the wind would affect weather.
The wind had picked up quite a bit and when I
tested it I got 28 spins in 10 seconds making
10 miles per hour. The Weather Channel said
12 MPH. There were cumulonimbus clouds
overhead and the temperature was dropping.
As it rained the wind got much faster. It only
rained for 15-20 minutes.

7.  On Monday Morning the there was very
little wind and what wind there was came
in small spurts. I caught the end of a spurt
when I started and it only spun 5 times.
That’s 2 MPH. Weather Channel said 3
MPH. There were no clouds and no rain.

8.  On Monday night there were some clouds
in the sky but it was dark and they were
covering up the moon so I didn’t have
enough light to see what kind they were. It
was warm and dry air outside with no rain.
My anemometer spun 13 times, so I got 5
mph and the Weather Channel said it was
6 mph.

9.  On Tuesday morning it was humid with no
clouds in the sky. It was warming up
outside and going to be a hot day. There
was no rain coming down and none that
night. My readings said the wind was at 2
mph but it was at 1 mph according to my
website.

10.  On Tuesday afternoon it was hot and
humid outside. There had been no clouds
all day and still weren’t any when I
checked. We got no rain throughout the
whole day. The wind had picked up a little
from the morning and I got 6 mph but the
website said the wind was 6 mph too.