Anemometer

[Steve Cahill]

We (Stephen Wasson, Dog-Boy, Donny, me, Randall and Dennis) changed the anemometer cupwheel and vane head today. Almost certainly the recently-replaced-but-sticky cupwheel was sticky because WD40, liberally distributed to avoid corrosion, got into the cupwheel bearings. They are intended to run "dry", and even a little oil in the bearing race will make it drag.

 

I also fixed the calibration factor. If all goes well, we should be okay now. One thing to watch for: part of the reason that I'd changed the cal factor was being there on a SW day when it felt like 10 but was reporting 14. This may have been due to compression effects affecting the local windspeed, with the new shape of the dune; please be aware of this. And, as always, please let me know if the reporting seems wrong.

 

Steve Cahill

[lgard...@sbcglobal.net]

Hey Steve,   Apparently I left to early to add any beneficial labor to the repair...oops. Calibration of the low speed range (8-14mph) with - or + 1mph would be ideal...at least for PG. Plus or minus 3mph in the 14-25 would be excellent. Beyond that, the compression factor and surface turbulence, above 25mph, wouldn't seem to be a factor except for history 's WoW factor.   my 2cents Thanks for your continued maintenance.   12AIR LG Always do right. It will Gratify some people and astonish the Rest. --- On Sun, 5/23/10, Steve Cahill <svca...@aol.com> wrote:

[Steve Cahill]

Hello Lee, and others:

Generally speaking I'm good with tweaking the readings to make the anemometer read the same as it has over the years. As far as I know, it's correct now to the accuracy mentioned in your note. If there's a good case to be made that it is reading differently than it has over the years, then tweaking is definitely in order.

 

Bottom line is that the calibration factors are identical to what was being used when the Litek was in service, but if consensus is that it's reading differently than it used to, the best would be to tell me how much it is off at both high and low speeds, and I will make adjustments.

 

Steve Cahill

[Tom West]

Hate to say it, but I went by the beach today around 4:00 pm. It was blowing in around 10 -12 mph and the cups on the anomometer were frozen still.

[Steve Cahill]

Aargh!

 

I'm out of town for the next week, but it being a mechanical problem, anyone interested should feel free to round up a club officer or two for supervision, take the pole down, and look at the anemometer. At least if it is full-stopped, there's something to look at.

 

I'd thought it was WD40 in the bearings the first time that this happened. The unit installed about 2 weeks ago, when we took it down, had a lot of WD40 inside where the spinner mounts, next to the bearings, and I figured that WD40 had gotten into the bearings - WD40 moves around something fierce. I wiped the mount off, and figured that the new one would be fine, and so would the unit that was being replaced, once it got degreased. Well, either there's more WD40 on the surfaces and it is wandering up into the new unit's bearings, or it's something else. Like wind-blown sand.

 

I can debug an anemometer with a fan and the test rig that I put together to validate the windtalker as I was building it, but finding time is a problem. More about this when I get back. Gotta pack for an early flight.