Topic: Davis 1 Young 0 after snow last night

[miraculon]

Well, I feel justified on having both sets of windbirds up now.
This morning the Davis anemometer cups were spinning, and the RM Young propeller was still. (I have seen the Davis set freeze up once or twice too, as well as my old AAG/DalSemi one).  The Young vane was OK and turning with the wind.

As soon as the sun came out and the temperature went above freezing, the Young prop was spinning again and matching the Davis speed.

There was a layer of ice under the snow this morning when I took my CoCoRaHS observation, so I suspect that fine snow got in behind the prop fairing and froze as ice. (hopefully not the bearings...)
Maybe this is why RM Young makes an Alpine version.... 

Greg H.

[Bushman]

Interesting.  RM Young is the anemometer on all the BC Gov't weather stations in the mountain passes, where they get some serious snow.

[miraculon]

I looked at the Weatherlink plots from both the "Davis Wind" VP2 console and the "RM Young" one.
I could see that the Young wind speed stopped after the rain gauge (melting snow) stopped reporting precip, and the temperature fell below freezing. The wind speed prior was only a couple of mph, and calm right before it happened according to the VP2 wind set.

This was only a few hours, it appears that the warming sun got it going again shortly after I looked up a the wind birds during the CoCoRaHS observation.

I think that any and all wind instruments, excepting possibly heated or ultrasonic ones can clog up with snow or ice at some point.

I just thought that this was an exceptional event, since normally the RM Young will be spinning with very light winds and the Davis cups will not respond.

Greg H.

[miraculon]

Well make that Davis 2 Young 0. The wind speed "propeller" has frozen due to about 1/10" of ice glaze. Both of my Davis (high on mast and down low on ISS are still going). Hmmm...

Greg H.

[twcmaster]

Ice and snow aside, how do the 2 compare overall? I know the Young does better at lower speeds and has a faster update rate, but how do they compare at higher speeds? Are the gusts generally the same?

[miraculon]

Ice and snow aside, how do the 2 compare overall? I know the Young does better at lower speeds and has a faster update rate, but how do they compare at higher speeds? Are the gusts generally the same?

RM Young is much more sensitive at low wind speeds than the Davis. This is true for the vane and speed. I simply do not buy into the notion that there is an inherent problem with the Wind Monitor vane/propeller concept because the vane turns into the wind when the Davis just sits there at some arbitrary direction. This is true during those proverbial "light and variable" winds. Once it picks up again there isn't too much difference.

At high wind speed with a lot of gusts, the Davis will catch higher readings. I have read about "overspin" on cup anemometers. Could be the case with mine.

There have been wind conditions that the two vanes are exactly in lock-step, other times there seems to be a skew between them . Not sure if they affect each other or not. I tried to avoid that, but I primarily was concerned about full 360° range on both without hitting each other when I installed them.

My RM Young is an eBay NOS Wind Monitor Junior. I think that these were primarily intended for buoys. They don't make this model any more. I got a good deal on it, way less than current prices. I suppose that the "Alpine" model might be better for the icing conditions that we had overnight. I fully expect it to recover once it has melted out the ice. It did the last time it happened.

Greg H.

[twcmaster]

Thanks for the info!!

[ocala]

Greg, just curious but how old is the Davis?
Reason I ask is that earlier this year I had a refurb done.
Before sending it back I noticed that the cups would hardly move at all during a light wind.
After the refurb the difference is night and day. The cups will move very slowly in the slightest of winds.

[miraculon]

I bought the Davis new in early 2011.

Greg H.

[ValentineWeather]

I had a Davis wind cup get stiff on me also while in Arizona, was having a different issue when I replaced anemometer with wireless unit and made the discovery. Really not sure how long it was like that but the new unit moved 10x easier.

[twcmaster]

There is now a newer version (as of 2013) of the Davis anemometer that responds better to lighter winds:

http://www.wxforum.net/index.php?topic=18867.0

[DaleReid]

I had my RM Young 5103 freeze the prop on one occasion in the last ten years.  It was an unusual slushy sloppy day, with light winds and slush on everything from cars to houses to roads to wires to ham antennas,  A lot of the fellow hams kept rotating their antennas and dropping the reverse every now and then to shake what load the could free.

As the temp went well below freezing and the wind let up, there must have been some slop melt over and freeze the prop.  direction still worked when wind returned.

They make an Alpine model that is all black and also has a super slippery feel to it, I guess intended to make this kind of thing not happen as easy. 

That being said, the Rainwise, Davis and the Peet Brothers all froze in the same conditions.

And with the smaller 'junior' version for bouys that you have probably added to the concern, but I'm thinking everything would freeze in supercooled rain and light winds.

[miraculon]

I had my RM Young 5103 freeze the prop on one occasion in the last ten years.  It was an unusual slushy sloppy day, with light winds and slush on everything from cars to houses to roads to wires to ham antennas,  A lot of the fellow hams kept rotating their antennas and dropping the reverse every now and then to shake what load the could free.

As the temp went well below freezing and the wind let up, there must have been some slop melt over and freeze the prop.  direction still worked when wind returned.

They make an Alpine model that is all black and also has a super slippery feel to it, I guess intended to make this kind of thing not happen as easy. 

That being said, the Rainwise, Davis and the Peet Brothers all froze in the same conditions.

And with the smaller 'junior' version for bouys that you have probably added to the concern, but I'm thinking everything would freeze in supercooled rain and light winds.

Thanks, Dale for your perspective on this. I would expect that the reduced moment from the shorter vane body might worsen icing as far as direction is concerned. Actually, the vane was still working in this case.

Greg H.