We never cease to be amazed at the range of interesting test equipment you can make with an Arduino, and another great example has been documented by Instructables member MariaL7 who shows us how to make a Spirometer. For the uninitated, this is a device to measure the volume of air that passes through a tube or cylinder which has a fixed diameter.
The Spirometer uses a Honeywell differential pressure sensor, which in itself is an interesting device that measures the difference in air pressure between two areas, and uses this data to calculate the air flow. Then with some maths which have been explained in the tutorial, the volume of air flowing through the tube can be determined and displayed with an inexpensive LCD shield:
If you need to add external hardware or devices to your next Arduino project, you'll need a protoshield to mount the external circuitry. In doing so, consider our range of ProtoShields. From the tiny LeoStick to the Mega we have a wide range to suit your application.