Build a Home Made Barometer
Introduction:
Air pressure and differences in pressure are among the most important weather makers. For
example, the centers of storms are areas of relatively low air pressure, compared to pressures around
the storm. High air pressure generally brings good weather. Keeping track of how the pressure is
changing is important for forecasting the weather.
Another importance of measuring air pressure is that differences in air pressure between places
cause the winds to blow (air moves from high toward low pressure).
The instruments that measure air pressure are called barometers, from Greek words for weight and
measure. Evangelista Torricelli invented the mercury barometer in 1643 and today's mercury
barometers are much like those of the 17th century.
In this project, we will build a simple barometer that will allow us to detect changes in air pressure.
From: http://www.usatoday.com/weather/wbaromtr.htm
Materials:
An empty coffee can
A large balloon
A large rubber band, one that will fit snugly around the coffee can
A pin
Glue
Straw
Paper
Procedure:
- Cut a large piece of the balloon and stretch it over the coffee can.
- Hold the balloon in place with a rubber band stretched around the can, over the balloon. Make
sure there is a tight seal around the rubber band. - Use a little glue (not hot melt) and attach the straw to the piece of balloon over the can. Then use
a little more glue and attach the pin to the other end of the straw (see diagram below.) - Take a piece of paper and place some regularly spaced lines on it.
- Set up the can and paper as shown in the diagram.
- Make several daily recordings of pressure for about a week. Make notes about the weather when
you take the readings.