Topic: Ice Storm and anemometers

[miraculon]

We got about 0.2" (5mm) of ice last evening before it turned to snow.
My VP2 on the roof froze up about the same time as the "propeller" on the RM Young. The vane is still OK this morning on the Wind Monitor Jr. but no speed.

The VP2 near the ground-mounted ISS worked a little longer before it too froze up. I was able to free both the vane and cups this morning, since I can reach it. Interestingly, the reason it wasn't turning was that the icicles that formed on the parts prevented movement. Once these were broken off, it started working again. So VP2's in town are 3-for-3 freezing up, one VUE and the Young speed.

On the Young, I think that water gets behind the propeller fairing and freezes.
One of the guys in our Amateur Radio Club has a Vantage VUE and I see that it is going again this morning. He also has a netatmo sonic anemometer and that is working. The Marina VP2 is still reading zero speed and no vane action. I wonder if the VUE handles ice better, or it is just a coincidence.

Greg H.

[BigOkie]

We got about 0.2" (5mm) of ice last evening before it turned to snow.
My VP2 on the roof froze up about the same time as the "propeller" on the RM Young. The vane is still OK this morning on the Wind Monitor Jr. but no speed.

The VP2 near the ground-mounted ISS worked a little longer before it too froze up. I was able to free both the vane and cups this morning, since I can reach it. Interestingly, the reason it wasn't turning was that the icicles that formed on the parts prevented movement. Once these were broken off, it started working again. So VP2's in town are 3-for-3 freezing up, one VUE and the Young speed.

On the Young, I think that water gets behind the propeller fairing and freezes.
One of the guys in our Amateur Radio Club has a Vantage VUE and I see that it is going again this morning. He also has a netatmo sonic anemometer and that is working. The Marina VP2 is still reading zero speed and no vane action. I wonder if the VUE handles ice better, or it is just a coincidence.

Greg H.

I've seen this happen occasionally on official ASOS/AWOS equipment as well; they just have better means to correct the problem once it happens.  I've had it happen to my VP2 anemometer once or twice since I've had it.  I would either spray warm water to free it, or if the freezing rain was still coming, let it go.  Usually freezing rain and calm wind are the culprits.  No sense in doing it if those conditions remain for any amount of time.  I'm not so OCD about my weather readings that I'm going to worry about a hole in my wind coverage given that I live in a climate that doesn't see it very often.

[DaleReid]

Greg, I'm thinking that it is just coincidence.  So many factors.  I have two Met One 034Bs mounted within feet of each other on the same horizontal plane for a test bed since I'm still working on them, and I've had one freeze up and the other keep rotating.  I have had a RainWise propeller swinging icicles around and around and not shut down, and as mentioned an RM Young freeze up until the sun got on it.

Young makes an Alpine model with slipperier coating and black color to absorb any heat there is to un-ice or snow better, but they charge a significant premium for them, and I don't think many buy them.

I'm thinking of a buoy in icing conditions and pictures of ships running with salt water freezing all over their cables and stuff, so I don't know of anything that is perfect for shedding that kind of ice.

I'm amazed that an ultrasonic is anything but an ice cube.  Of all, I'd think they would be the first to go and the last to recover unless he had a heated version.

Dale

[ValentineWeather]

Only sure thing is a heater until the power goes out. 

[miraculon]

Only sure thing is a heater until the power goes out. 

The local airport KPZQ has what I believe is a Vaisala. That kept working throughout the ice storm. I am thinking that it must be a heated model.

Greg H.

[DaleReid]

Greg, is that an ultrasonic or mechanical one do you know?

[DW7240]

Hi,

My answer to this is to construct a cheap anemometer heater, I used one of these......

http://www.ebay.ca/itm/12V-5W-Polyimide-Flexible-Adhesive-Thermo-Foil-Heater-Heating-Film-35mm-x-30mm-/121690849594?hash=item1c5557013a:g:zlkAAOSwHnFVkKJ-

then constructed an enclosure with power on LED and thermostat out of a 1 1/4" long piece of 1 1/2" pvc waste pipe cut in half, which made a half circle.  Attached to this a 1 1/2" mast clamp, then lined the pvc with pipe insulation foam stuck to a piece of aluminium which acted as a barrier to the heating foil (didn't want the foam catching on fire)

The heater was then fed by a long cable up the mast, powered by a 12v dc supply, connected to a digital stat.

All items (except pvc pipe and foam / aluminium) purchased of ebay, total cost less then $15.00.  Anemometer kept running through several hours of freezing rain, stat switches on @ -5 C, switches of @ +10 C. Heater normally on for around 1 - 1 1/2 minutes, so it's fast and has been running for the last 6 months without issue.  Obviously the heater turns off well before any sort of damage can occur to the anemometer, heater can reach +200 C, but the surrounding air keeps things at perfect temp.  Even if this setup fails (heater burn out) replacement is only $8.00.

Not bad for a cheap setup, works, and looks the part, the heater unit after construction is only noticeable via the slightly fatter anemometer.  Incase your wondering I have the older (reed switch) style of anemometer, the body of which is taller, the newer (hall effect) style is not as tall so when I have to replace the unit could pose a problem as the heater foil can not be cut, so fitting it would be a challenge (but not impossible)

Nick. dw7240.com.

[miraculon]

Only sure thing is a heater until the power goes out. 

The local airport KPZQ has what I believe is a Vaisala. That kept working throughout the ice storm. I am thinking that it must be a heated model.

Greg H.

It is mechanical. It looks like a WA15 from the road, but I can't get real close to it. I am not completely sure that this is the model.

http://www.vaisala.com/en/products/windsensors/Pages/WA15.aspx



Greg H.

[eyecue]

Armor All on the exposed plastic at regular intervals seems to work for me. Reduces UV damage too.  Ice storms are unique though with the water freezing on impact.

[miraculon]

We had another ice storm, this time with about 0.2" of ice. Prior to the ice we had very wet snow (lake effect enhanced storm) that is clinging to all East facing surfaces. This includes all three of my solar panels for the anemometers. (2x 6332 and a Universal Anemometer Interface for the RM Young).

I don't know whether there is any light getting through the inch or so of snow/ice clinging to the solar panels, or they are running on battery by now. (despite good sun today, but sub-freezing temps). So this coating of snow is crusted over by glaze ice. Yuck.

This time the Young is spinning away and the vane is working fine, where the VP2's are stuck. The VP2 anemometers seem to get hung up by a small icicle that hits the arm. I broke the lower one (by the ISS) free earlier, but it froze up again. Direction on the low one is still OK, but the higher mast mounted one has both direction and speed frozen.

Tomorrow and early this coming week it is supposed to warm up. I have been through ice storm stopping wind instruments many times before, so this isn't anything new.

Greg H.

[DaleReid]

Greg,
When I moved out here 37 years ago we put up an air circulating solar system with a garage roof full of panels.  Even with 3-4" or snow or 1/2" of ice, the sensors indicated warming shortly after the sun hits them.  Of course as soon as they warm enough, the inclination is so steep that an avalance occurs and down comes the snow.

I know that RM Young makes an Alpine version of their wind monitor which is all black and has a slipperier coating on it.  I have one but not up yet.  I was worried about it getting too hot in July with direct sun on the black but the spec sheet says that it is good for hotter than it will get in most deserts.

[miraculon]

Thanks, Dale

As an experiment, I put a white towel over a spare Davis solar panel that I have and I was able to get some voltage out using a bench light. It was less than 2V, but maybe there is enough filtering through the snow to get a partial charge on the super-cap. It is supposed to warm up a bit today and it is sunny so I hope that the snow/ice mass will slide off today.

Greg H.

[DaleReid]

A quick and dirty test, to be sure, and I'd only point out that the absorption spectrum of cotton is different from frozen water.

I do know that there are fabrics which are treated to block UV, so that sunburn can be avoided. One would think that cloth would make perfect shade, but apparently enough UV gets through to allow some sensitive persons to get enough through their shirts to burn them.

I know that certain glass lets more radiation through than other does, hence the fancy glass panels in my collectors.  By the way, they've survived a few moderate hail storms, thankfully since I'd have no way to replace them if they were broken.  The company making them shut down a decade or more ago, and I don't think I could find glass like that anywhere.

Keep us posted on your real life adventures.
Dale

[miraculon]

The Davis VP2 wind set is now freely moving. The anemometer just loosened up within the hour.

Although it is 35°F and the sun is on the Xmitters/UAI, still no joy on the solar panels. I just hope that the run time of the 6332/UAI  is a long time on battery, in case the charge is insufficient....

I see that the local Marina's VP2 just broke free as well.

I'll attach a photo of the snow and ice encrusted 6332 and UAI. The VP2 transmitter is already in the shade, so this is a lost cause for today.

Greg H.

[miraculon]

The UAI and top 6332 (for RM Young) are now clear of ice/snow. I heard some noise outside this afternoon, apparently when the ice let go. The bottom one (VP2 set) is still hanging on, but there is some of the solar panel exposed now. Earlier the ice was clear on this bottom one and hopefully the solar panel was able to charge the super-cap.

Greg H.

[DaleReid]

Its never a good thing to hear ice crashing.

I know the local TV tower (980') occassionally has rime ice and people don't park under it or the guy wires till it clears.

I have (had?) an ultrasonic RM Young wind monitor that has one of it's three little posts broken off when a falling piece of ice hit it just wrong.  Despite trying to get it exactly in position there is enough off that it won't work. 

I don't like falling ice sounds.

[miraculon]

Its never a good thing to hear ice crashing.

I know the local TV tower (980') occassionally has rime ice and people don't park under it or the guy wires till it clears.

I have (had?) an ultrasonic RM Young wind monitor that has one of it's three little posts broken off when a falling piece of ice hit it just wrong.  Despite trying to get it exactly in position there is enough off that it won't work. 

I don't like falling ice sounds.

The day after Christmas this past year, the wife and I were driving to Michigan's UP where my folks live. We got across the bridge OK, but the back up at the toll booth was really long, a lot more than I have seen in years including Deer Season. After a while, I heard on the news that they closed the bridge for an hour or so due to falling ice, we just arrived after they reopened it and they were still processing the backlog of vehicles. I understand that the ice was falling off of the main cables and vertical suspender cables. I am glad that we only had the toll booth delay, a minor inconvenience.

Greg H.