Frozen sensors

[Blackmyre]

My station was reporting suspiciously dead-calm winds this morning. On investigating, sure enough, both the speed and direction sensors were frozen. Is this an unusual phenomenon, or am I likely to have to get out there with a ladder and a hairdryer regularly over the winter?

[steve]

When I used to live in cold places, I had this regularly. Both freezing temperatures and heavy snow cause problems.

Steve

[TrOjAn]

I am surprised at that!! its been between 0 and -7 for last week or so, snow today etc and its all spinning fine.. maybe Im lucky but thats unusual

TrOjAn

[Blackmyre]

Any recommendations (other than moving somewhere warmer)?

[steve]

Heated anemometer?

I think that whether you get the freezing up problem or not depends on how humid or rainy it was prior to the freezing.

Steve

[Blackmyre]

between 0 and -7 for last week or so, snow today etc and its all spinning fine

It's been colder here too, but yesterday was the first rain we've had since setting up the sensors, and we had a sharp sudden frost during the night. I assumed it was the combination that caused the problems. The wind speed sensor had frozen again by 4:30pm today though (no rain) so I can't help wondering how useful it's going to be over winter...

[steve]

One thing I did try when I lived up in Wanlockhead, where it tended to be very damp, very cold, and very snowy, in rotation, was to squirt some WD40 in to try to keep the damp out. It helped a bit, I seem to recall, but <insert standard disclaimer>. When the problem was heavy snow, I used to go out and throw snowballs at it - <insert further standard disclaimer>.

Steve

[harrym1byt]

Thinking about it, the WD40 might be why mine has not frozen up - after it froze up the first time I gave it all a good squirt, not to stop it freezing up, but because there was a suggestion that rain on the rain sensor would bead up and drop into the buckets quicker. Thus making the rain sensor a little quicker to respond to rain falling.

It might be that the WD40 helps prevent the moisture collecting and freezing.

[aadal]

Frozen sensor or much snow on many times here 24 hours ago -7.6 to 1.5 today and spinning

[Blackmyre]

I'll give WD40 a try then - thanks for the tip. Probably not today though, it's too damned windy!

I could hear the wind whistling away during the night, the first decent winds we've had since I got the weather station. Looked out of the bedroom window this morning, wind still howling but no movement from the speed gauge. I was resigned to getting the ladder out again, but my wife pointed out that when the wind dropped slightly it was clear that the gauge was in fact whizzing round - so fast that it had seemed static. I'm sure that's familiar to people who've had these things for ages, but it amused us That's with gusts just over 30mph, and we're sure to get much stronger than that from time to time. Do these "cup" type sensors have inherent speed limitations?

[JMB]

We had several days last week when it stayed below zero with absolutely no wind, I think that it is when they tend to freeze up. If there is some wind then perhaps can be enough to keep free. Mine is probably too low down at the moment, it might catch the sun a bit more if higher which could help stop it freezing up. I just tried to remember to give a tap when I went outside.

You can always put it in a "dustbin" like the one on the Cairngorm that pops up occasionally to take a reading them disappears beck in the warm.

MB