Posted by admin | Posted in Thermo Hygrometers | Posted on 09-10-2010
Tags: anemometer, diy, weather, weather station anemometer, weather station anemometer height, weather station anemometer review, weather station anemometer tower, weather station anemometer uk, weatherstation, wind, wireless
A look at what is currently available on eBay
 La Crosse WS-2811 Wireless Weather Station Anemometer US $215.00 
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 SOLAR WIND SPEED METER GAUGE ANEMOMETER WEATHER STATION US $119.75
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 PRO HOME WIRELESS WEATHER STATION ANEMOMETER WIND RAIN US $189.95
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 WEATHERWISE MINI WEATHER STATION WIND METER ANEMOMETER US $29.95
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 Flowtek 4836C Weather Station Wind Direction Anemometer US $125.00
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 Anemometer Thermometer Wind Speed Meter Weather Station US $20.21
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 Kestrel 4000 Olive Drab Anemometer Weather Station US $249.00
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 LA CROSSE WS-1611 WEATHER STATION ANEMOMETER WIRELESS US $94.99
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 Taylor Wireless Weather Station With Anemometer #2752 US $65.00
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 New Wireless Weather Station WMR100N (Rain, Anemometer US $160.00
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 PI-W-PWS-1000 Wireless Weather Station Anemometer US $149.99
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 Kestrel 4000NV Weather Station Anemometer-5 yr warranty US $259.00
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Anemometer Location; Roof Or Field?
I have a Home Weather Station that includes an anemometer to measure wind speed and direction. I currently have it mounted unobstructed to the base of an antenna about four feet from the highest peak of the roof of my house.
Is this the best place for the device to be mounted or would it have more accurate readings on a pole at ground level? I have a feeling the house may be acting as a wind deflector as an airplane wing would.
Thank you.
"Mounted on a pole above ground level" I should have said.
It is often a trade off between convenience and accuracy. However, I experimented with just such a system many years ago and found that if the anemometer is located at least 10 feet above the highest point of the roof, it is reasonably accurate. Anything below that and I found the readings were often too high and direction was more erratic compared to another anemometer that was a few hundred feet away and at a height of 10 meters in an open field.
The National Weather Service uses 10 meters (close to 33 feet) for anemometer height for their instrumentation which I believe is the height used by the World Meteorological Organization. The U.S. Forest Service uses 20 feet for their instruments and their purposes.
A rule of thumb on exposure is that the anemometer needs to be at least 7 times the height of the instrument away from any obstructions that are at or above the height of the instrument. So if your anemometer is at a height of 10 meters then it needs to be at least 70 meters, about 235 feet, from the nearest obstruction at or above the height of the instrument.