Anemometer snowed/iced up

[Gina]

Is anyone else here in the UK getting their anemometer snowed or iced up and stopped from turning? This afternoon after about an inch or so of snow I noticed the anemometer wasn't moving at all and that there was snow around it. I gave it a tap with a long stick and got it free and it then slowly rotated. The vane was moving freely. Tonight, it's snowing again (and freezing) and the AWS shows no wind and I think it may be frozen up again - but I'm not going out again tonight. Admittedly, we are having rather unusual weather for here.

[daj]

Indeed

https://cumulus.hosiene.co.uk/viewtopic.p ... 246#p16246

I have had no wind reading since 18 December!

[Gina]

I had a feeling I'd seen another thread on this subject Sorry for starting a new thread

[daj]

I'm surprised that Devon is getting it as cold -- that must be unusual. Although looking at the weather forecast today it looks like most of the UK is in the freezer

[Gina]

Yes, it is unusual for us and for much of the UK - worst for 30 years they said on the news! I see you are in one of the coldest and snowiest places in the UK. I've been to Scotland several times and love it, but it does get very cold in winter. Yes, I have been in Scotland in winter.

[Super-T]

Not sure if this is related but my Anemometer froze in sunny Auckland but it was due to a lack of lubrication in the bearing....and you know what a lack of lubrication can do
I just trickled some oil in and then sealed it over with petroleum jelly.

[gemini06720]

Gina (and all other deep-freeze UK members)...

...I gave it a tap with a long stick and got it free and it then slowly rotated...

Please, please, remember that the plastic with which most (lower priced chinese made) weather stations becomes very sensitive (read: brittle) as temperature gets to or below the freezing mark...

Years ago, I 'destroyed' the anemometer on my then fairly expensive La Crosse weather station when I tried to remove the snow on the equipment - the anemometer was freely replaced by La Crosse with the above warning...

[goldrush]

I mentioned in the other thread that I also had problems. Interestingly, I have 1 anemometer on a 30 foot pole in the middle of a field and because it is subjected to higjer wind speeds and rarely, if ever zero, it has been ok. I have another at only 8 feet and shielded by trees (both the same anemometer, as an experiment) and because it often experiences low or zero wind levels, it freezes regularly especially in snow.
There are 2 problems I have observed, both due to poor design.
1 snow/ frozen water builds up on the top rotating part and in light winds, because the cups are "small and arms short" there is insufficient torque to keep it moving, so it freezes. In fact very, very little resistance will stop the rotor.
2. similarly is gets driven in the gap between the rotating and stationary part and then the same thing happens.

The second problem has been helped by spraying the joint with WD40.
Light snow will often build up in te cups in low wind, but generally get thrown clear when the wind picks up unless "wet snow" and freezing hard. Only cure for that, I think, is to move to sunnier climes:-)

Super-T mentioned lack of lubrication of the bearings. Both of my 1080 anemometers have a sealed bearing system so access to the bearings is not possible without surgery, so re-lubrication is a hit or miss affair
Both "problems" could probably be helped by adding a "skirt" to the rotating element which shields the joint with a suitable gap to the fixed element. However, low torque will always be a potential problem with this design

[Repairman77]

Yes I've noticed that there is little or no torque on the bearings. However as a plus point it does allow very slow wind speeds to be measured. A neighbour 1/4 mile away has a more expensive system with a larger anemometer and his is sometimes stationary at low speeds when mine is still moving.

It is a pity when they freeze up though; nothing much you can do about it. I've found mine usually frees itself up as soon as we get around 7mph of wind speed.

A good warning about the brittleness of plastic when it gets cold; this can also happen when plastic gets old as well, although the plastic on my WH1080 does look of a reasonable quality. Best to leave them well alone when it's frosty I think.

Mike.

[Gina]

I was careful to tap it lightly - it didn't take much. It was frozen up again last night but around 04:40 it suddenly freed itself as the wind got up. The wind strength gust graph shows a sudden jump from zero to 7mph. We now have a blizzard!

[scoobs]

When mine did it last week i gave it a squirt with car windscreen deicer

[Gina]

When mine did it last week i gave it a squirt with car windscreen deicer

Good idea

[FrostyJW]

After the fall of snow here in Birmingham on Monday & Tuesday, my sensors were covered in about 3" snow, so I dusted it off next morning, but the wind speed sensor would not completely free up, and kept sticking - probably due to moisture under the rim that was frozen. The wind direction sensor was unaffected. The anemometer remained stuck for 2 days, but today I sprayed the top and under the rim with WD40 as mentioned in a previous posting, and after 30 minutes it started to work again without any problems, and is not sticking at all. However, if we get another -7C tonight it might freeze up again - just waiting to see, though I guess if there is a continuous breeze all night, then it will be OK. The other recent suggestion of using a car windscreen de-icer aerosol spray seems like a good idea too!

Lets hope it warms up a bit next week! I am still very surprised at the relatively high humidy readings in this cold but 'dry' weather - yet if you go to the BBC Weather pages (and for my area) it shows the readings are pretty accurate - ie varying between 85 and 95%.

John W

[Gina]

We had a blizzard yesterday afternoon, evening and overnight and my anemometer is stuck again. It was working until O530 when the wind dropped below 4mph when it just stopped. The vane is working fine, showing SE earlier and now S and the console agrees. But the Cumulus wind direction graph has been showing North from the time the anemometer stopped

We are having a slight thaw so I expect the anemometer will free up a bit later.

[Gina]

Yes, it has freed up now Got going again just before midday and now all readings are as expected