Topic: Wind speed on Ecowitt HP2551 not correct

[RonM]

I am new to weather stations and am experiencing a problem with wind speed on my Ecowitt HP2551. It seems to be approximately 1/2, or less, the actual wind speed. I've tried resetting it but haven't been able to get it to report wind speed properly. All other measurements seem to be ok.
Thanks
Ron

[kheller2]

With what are you comparing the wind speed against?

[RonM]

Using the Windy app, plus local weather reports. I live on the coast and the wind is noticeably stronger at the moment than normal.

[Gyvate]

depending on the mounting location of our outdoor array your wind microclimate can be such.
Comparing with other services in itself might not be so helpful.
If your outdoor array is mounted higher than 10 m above ground and the area around is free of obstacles, you could compare to nearby (!) PWS provided they have a similar free positioning. Otherwise you compare to their microclimate, which can be quite different.
In fact in most of the cases you measure your microclimate which differs +/- from standardized WMO conditions.
And to compare to windy may not be accurate for the same reasons.

Also, you felt wind is a 3D experience and the WS69 array measures only 2D due to its design. A WS80/WS90 ultrasonic anemometer would also measure 3D and will produce different results from a WS69.

[havtrail]

Not sure about Australia, but generally the standard for measuring wind speed is at a height of 10 meters above ground level, in a clear area. If your anemometer is mounted lower than that, it will read a lower wind speed. Mine is at about 2 meters, and it reads about 1/2 the "official" wind speed and gust speed.

Rich K.

[Ra1nman]

Not sure about Australia, but generally the standard for measuring wind speed is at a height of 10 meters above ground level, in a clear area. If your anemometer is mounted lower than that, it will read a lower wind speed. Mine is at about 2 meters, and it reads about 1/2 the "official" wind speed and gust speed.

Rich K.

Indeed, I had overlooked this for some bizarre reason and am currently working out how the Ecowitt gain formula relates to a multiplication factor in percentage. Technically at 2 meters you would require around 1.29-1.30 multiplier on wind readings, my GW2000 range for 'gain' is 1.00 to 5.00, in discussions with Ecowitt as to how this relates! report back if I get anything useful.

[sky_watcher]

I am new to weather stations and am experiencing a problem with wind speed on my Ecowitt HP2551. It seems to be approximately 1/2, or less, the actual wind speed. I've tried resetting it but haven't been able to get it to report wind speed properly. All other measurements seem to be ok.

I have a couple of HP2551 units. At home, my wind speed is generally always less that the local airports (Parafield and Edinburgh) that I am between because of a number of factors: (1) Height of sensor, (2) a depression in the local area around my street, and (3) surrounding trees.

If your sensor is actually measuring 1/2 or less, then you would expect that the cups would not be free spinning. Have you tried blowing on them gently and seeing if they are free spinning? If they are not free spinning, then there is likely a bearing issue. If you are in an area with lots of spiders, they can affect your sensor. I sometimes get that problem on the wind measurement on my houseboat.

The next link in the chain would be the reed switch and its cable which measures the rotations of the cups using a magnet on the shaft. If your wind speed difference seems erratic, it may be a dud switch or weak magnet, but I think that is less likely than  a location problem or bearing fault.

Good luck figuring it out.

Mark

[Jure]

I am experiencing the same with my new Froggit HP1000SE - the "Y" version of Ecowitt HP2551. How do I know? I have the old HP1000 mounted next to the new one and the old one is reporting higher wind speeds. Which is correct? Judging by my very unscientific method - the old one.

Next is the "brake" on the wind vane. It's pointing in one direction and if a very light wind begins blowing from a different direction, the vane will not move. If anyone knows how to get rid of that "brake"...

These new stations also have a problem with frost creeping up to the wind axes from below. The opening is just too large compared to the old station. I used a lot of scotch tape to reduce the opening to almost nothing. It helps. More here: https://www.wxforum.net/index.php?topic=44753.0

Jure