Anemometer (wind speed sensor) design

Hey Guys,

I am working on building a fairly simple yet effective and accurate wind speed sensor for a weather station of mine.

I know there are tons of these projects on the internet however this particular part of my project forms part of a massive project, I can't afford to dedicate too much of time to this particular component as I have a deadline to meet.

I have researched techniques such as ultrasonic sensing. It seems pretty good, however the projects I have seen, these sensors are pretty complex.

I was hoping someone could shed some light on this for me, I would greatly appreciate it.

Also I have an idea of my own but I am not sure if it work, I want to have the wind turn a blade that cuts the beam of a photo-interrupter. and from this obtain an RPM for the blade, and thereafter convert that RPM to a wind speed. I am not too sure about the specifics of the technical details, however I do know there will be some resolution issues to cater for.

Any help will be appreciated
Thanks in advance

If you can mount a magnet onto the wind wheel you easly can use a hall switch or small encoder to get x pulses per rotation. Then you need to calculate the speed with a microcontroller. You could use also an air flow sensor. The simples methode I think is the bike computer.

Enjoy your design work!

Hey there,

Thanks for the reply, I am considering the magnet with the hall switch. I am not too sure about the encoder as I haven't worked with one of those as yet. But I will definitely keep my options open.

For now I am researching the magnet + hall technique. If you have seen any good application documentation for this technique, could you please point me in its direction?

Thanks very much

For the blade, you might use a computer fan such as shown here. The trick is finding a fan that turns very easily with no magnetic "cogging" effect.