Wind vane freedom of movement

[miraculon]

We went up on the roof of our building to inspect our VP2 installed in April of 2011.

The only thing that I questioned was the wind vane. The movement seems slightly stiff. I am thinking that when I installed my own VP2 in January of this year that it turned more easily.

Is there a slight 'drag' feel to the vane? Maybe it is the potentiometer wiper and I am accustomed to one (AAG) with magnets and reed switches, which only have the bearing friction.

The anemometer is very responsive and everything else checks out OK. Am I just imagining things?

[Skywatch]

I have the same problem with mine. I have a WMR200 and the Vantage Pro2 anemometers installed together not even a foot apart. The WMR200's wind vane is always moving but the VP2 doesn't seem to do anything until the wind hits 3 MPH. I noticed this from day one. I think maybe an issue with the potentiometer. I've sent an email to Davis about this. Maybe the VP3 will have a better sensor.   

[johnd]

TBH I'm not sure that a small amount of friction on the vane is any bad thing (provided obviously that it's not abnormal/excessive) because it provides a degree of damping to the direction readings. If you look carefully at a log of successive direction values from a VP2 anemometer in most non-ideal locations (ie where the wind gusts and buffets around whatever structures are in the vicinity) you'll see that is already typically a very marked amount of direction variability minute to minute. This would be even more pronounced if some limited damping or averaging weren't applied to the readings.

[stevebrtx]

I still have my OS on the roof and the Davis anemometer is less sensitive at low wind rates. The OS cups will turn with only a breath while it seems to take a bit more for the Davis, however, the OS tops out at 30mph, never registered more than that, I suspect when the stormy season starts next month the Davis will record higher winds.