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Miscellaneous Debris => Weather sensors, design, analysis, discussion, home brew => Tech Corner => Anemometers => Topic started by: DanS on July 24, 2016, 04:38:40 AM

Title: Piezo anemometer
Post by: DanS on July 24, 2016, 04:38:40 AM: SLOweather and his flycup anne idea got me to thinking of another different approach and wonder if anybody has tried it. It would use a piezo chip that gets squeezed from wind pressure. Mount the whole thing on a vane to track with wind direction.https://en.wikipedia.org/wiki/Piezoelectric_sensor [ You are not allowed to view attachments ]
Title: Re: Piezo anemometer
Post by: vreihen on July 24, 2016, 06:24:43 AM: How about a tall pole with 4 force sense resistors (FSRs) in a 90-degree N/E/S/W diamond pattern on the ground? Zero moving parts, and you can calculate both wind speed and direction from the stress on each FSR.....
Title: Re: Piezo anemometer
Post by: mcrossley on July 24, 2016, 06:27:54 AM: I did see a similar design once that used four (or two at right angles, i can't recall exactly) piezoelectric sensors that just used an upright rod. From that you can determine both wind strength and direction.

Turbulence around a cylindrical rod may be an issue causing rapid fluctuations in the readings?
Title: Re: Piezo anemometer
Post by: Cutty Sark Sailor on July 24, 2016, 07:14:28 AM: https://www.google.com/search?q=pitot+tube+anemometer&rls=com.microsoft:en-US:IE-Address&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiyzYDN-4vOAhVF6iYKHaooByIQsAQIQg&biw=1432&bih=833

https://www.google.com/search?q=piezo+anemometer&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi4yKeq_YvOAhVHTSYKHQl6ArsQ_AUICSgC&biw=999&bih=930
Title: Re: Piezo anemometer
Post by: miraculon on July 24, 2016, 08:31:53 AM: Quote from: mcrossley on July 24, 2016, 06:27:54 AM
I did see a similar design once that used four (or two at right angles, i can't recall exactly) piezoelectric sensors that just used an upright rod. From that you can determine both wind strength and direction.

Turbulence around a cylindrical rod may be an issue causing rapid fluctuations in the readings?

Absolutely, see this post (about the Davis rain gauge). http://www.wxforum.net/index.php?topic=26463.msg255276#msg255276 (http://www.wxforum.net/index.php?topic=26463.msg255276#msg255276)

(https://upload.wikimedia.org/wikipedia/commons/b/b4/Vortex-street-animation.gif)

How much this would affect the piezo output is anyone's guess.

Greg H.
Title: Re: Piezo anemometer
Post by: Garth Bock on July 26, 2016, 09:53:34 AM: What about freezing rain, rain drop accumulation, or snow build up ? That would interfere with it as well.
Title: Re: Piezo anemometer
Post by: mcrossley on July 26, 2016, 10:43:58 AM: You need a hot stick!