Topic: Davis vs Cheaper (Ambient/Ventus etc.)

[Weatherwx85]

Hi,
I currently have Ventus weather station (ambient ws-2902a clone) and have a problem where wind direction seems very sporadic and the vane seems hyper sensitive and seems to spin in circles far too easily. If I were to buy a VP2 Plus and install the anemometer in the same location (12ft AGL) would it likely be any better? I appreciate no one can give me a definate answer but some experience would be appreciated if possible?

Thanks

[johnd]

If the location is too sheltered to give a meaningful wind direction then no anemometer is going to do any better. Is it too sheltered?

[Weatherwx85]

No not sheltered, it just seems too variable, almost like it has too much to make a decision?

[Weatherwx85]

Basically it seems to do a 360 spin too easily when wind starts.

[Weatherwx85]

30 feet from the nearest building (2 storey house) in the UK

[Weatherwx85]

I contemplated putting a VP2 anemometer on the chimney (not used) but that’s kind of a nightmare for me to get to and I would probably kill myself installing

[galfert]

Have a look around WU and other services for your neighbors. Find a VP2 near you to compare.

[Weatherwx85]

Current one seems better when we have steady wind not stop/start.

[Weatherwx85]

Have a look around WU and other services for your neighbors. Find a VP2 near you to compare.

Can you filter by station?

[galfert]

Okay I remember you. Your fence may be the cause. That looks like a solid fence and not a shadow fence. That fence doesn't let any wind through.

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Try moving your station to a more clear area even just temporarily. Stick it in the front yard just for a day or two if you have no options. Who cares what the neighbors think. Tell them it's a test. Put a sign on it that say "temporary test".

[Bushman]

My Acurite station anemometer looks like it is on speed.  Averages out OK for direction, but constantly whirling - and it is in good, clean airflow.  My Davis is much better.

[Weatherwx85]

That’s me, it is higher than that now though. I can maybe move it back a bit but would still be on a fence.

[galfert]

Have a look around WU and other services for your neighbors. Find a VP2 near you to compare.

Can you filter by station?

You can't filter by station type. You just have to click on neighbors from the map and the click on the "i" to get station type.

[Weatherwx85]

My Acurite station anemometer looks like it is on speed.  Averages out OK for direction, but constantly whirling - and it is in good, clean airflow.  My Davis is much better.

This is what I see, direction is ok but I do wonder if something more expensive would jump around less, not sure if they have more dampening or just move at a higher speed only.

[galfert]

The newest Fine Offset anemometers in the WS-2902A clones have been designed with more dampening than the prior WH24 generation.

When I compare my Ambient anemometer with nearby Davis VP2 stations I see similar results for wind direction. Some days are good and show steady wind direction even when windy. Other days it's all over the place and I see that on my station as well as Davis. The key thing though is that there are good days. If you have no good days then maybe something else is the matter. Or it just may be that at your location it is normal to have wind from all over all the time. You need to look at your neighbors. Or give us your WU Station ID and we'll compare and come up with some analysis.

[Weatherwx85]

Happy to look, but my WU ID is ITAUNT6

[Weatherwx85]

Let me know what you think.

[galfert]

I looked at your data and it looks to me like things are mostly normal and as expected. I looked for nearby neighbors with Davis on WU and I found none. Everyone has a Fine Offset clone. But we can still compare them. Your wind is tracking well. You do have days of considerable wind with defined wind direction. Yes I saw days with wind that was more undefined for direction but that mostly fell when wind was below 5 Mph. You should also know that graphed wind on WU has two North....one on top and one below. Often when it seems it is all over the place it isn't and it is tracking North but it bounces between NE and NW which is North.

Also since you have a CWOP ID you can compare yourself to a few more things. You have a MADIS score of 100% for wind direction. You can also compare your station to some neighbors and ignoring a couple outlier stations and you plot right in line in the middle with your neighbors.
https://weather.gladstonefamily.net/qchart/F5335?date=20190708&addnl=03840&addnl=F4322&addnl=E4239&addnl=C3517&addnl=AT076&addnl=E1516&addnl=D7857&Add+to+charts=Add+to+charts&.cgifields=addnl

You should upload to AWEKAS for even more fun comparison tools. But they don't have wind direction comparison..only speed and gusts for wind comparisons.

[galfert]

This is the closest VP2 I found to you at 13.5 miles away. Maybe there is a closer one that I missed, but this one is close enough I think for comparing wind.

https://www.wunderground.com/dashboard/pws/IDEVONCU2/graph/2019-07-4/2019-07-4/daily

This VP2 is also FW4322.

Notice how on July 4th (my link above) their wind was also all over the place like yours. Other days it tracks well, just like yours.

So I think what you are seeing is normal.

[CW2274]

For comparison's sake, I just had my VP2 anny serviced so I got to study it's "behavior" in detail and it takes 3mph (4.8kph) of sufficient crosswind to make the vane reposition. The cups them self will report a 1mph (1.6kph) wind all day long.

[Weatherwx85]

For comparison's sake, I just had my VP2 anny serviced so I got to study it's "behavior" in detail and it takes 3mph (4.8kph) of sufficient crosswind to make the vane reposition. The cups them self will report a 1mph (1.6kph) wind all day long.

This is where I think the difference will be, I notice mine changes when the wind speed is reported as 0.3/4mph then as wind picks up it settles down.

[CW2274]

For comparison's sake, I just had my VP2 anny serviced so I got to study it's "behavior" in detail and it takes 3mph (4.8kph) of sufficient crosswind to make the vane reposition. The cups them self will report a 1mph (1.6kph) wind all day long.

This is where I think the difference will be, I notice mine changes when the wind speed is reported as 0.3/4mph then as wind picks up it settles down.

What is reporting such a minute speed for you?

[Weatherwx85]

Sorry I don’t understand the question, forgive me.

[CW2274]

Sorry I don’t understand the question, forgive me.

No problem, you state that your vane spins at a measured speed of 0.3-0.4mph. I'm just curious what is the instrument that is reporting such a tiny amount? All in all, it doesn't really matter, if your vane is indeed spinning at such a low wind speed, measured or not, that would definitely explain it's constant movement.

[Weatherwx85]

Hi,
It is a Ventus (Ambient WS-2902a clone) the update interval is 16 seconds to the console and WU the low wind speed is reported by the station itself.