WS2080 and strange anemometer readings

[AustinTX]

Hi,
I got a new WS2080 station last week and have set it up this weekend. Everything works fine except that the anemometer registers in some strange quanta: from 0 it would go to 0.7 and then to 1.6 etc. (It does increase with the rate of spin, but I don't have any other device to actually verify the numbers: they do feel correct) The specification says the resolution is 0.1 mph. Would not that mean that for a very slow wind it would first read 0.1 and then 0.2 and so on?

Has anyone else seen a similar problem? Thanks!

[W3DRM]

Hi,
I got a new WS2080 station last week and have set it up this weekend. Everything works fine except that the anemometer registers in some strange quanta: from 0 it would go to 0.7 and then to 1.6 etc. (It does increase with the rate of spin, but I don't have any other device to actually verify the numbers: they do feel correct) The specification says the resolution is 0.1 mph. Would not that mean that for a very slow wind it would first read 0.1 and then 0.2 and so on?

Has anyone else seen a similar problem? Thanks!

First of all, I know nothing about the WS2080 itself but am wondering if the jumps in wind speed you are seeing is simply due to the rate at which wind speed is reported by the WS2080. For example, if it sends wind velocity data every 30 seconds and the wind were increasing during that time, you would only see the data that was reported every 30 seconds. Between those sampling times, the wind could change up or down quite dramatically thus, giving you the type of readings you are seeing.

Secondly, welcome to the WXFORUM! Please feel free to browse around and join in on the conversations. You'll find many great weather websites and an overwhelming amount of information for just about anything that is weather-related.

[W3DRM]

Found the user manual for the WS2080 and it looks like the transmission rate is once every 48 seconds. The manual indicates you can display the wind speed as either the Average or Gust value detected during the 48 second cycle. Thus, you are not likely to see incremental values as you have mentioned in our original post.

Am wondering if you have the unit set for m/s (meters per second) or some other setting that would give you fractional wind speed readings. I suspect that even though the specs are for 0.1 mph resolution, it may actually only provide whole unit values when displaying mph. Someone else in the forum who has one of these units may be able to give you more information than I have.

[ericfynne]

It's a feature of the way the anemometer is constructed. 0.7 mph is approximately the minimum speed that it can measure, and it will only ever display approximate multiples of that. It measures in m/s, so the odd values you see are a result of conversion to mph and a rather strange rounding algorithm. The speeds you will see are 0, 0.7, 1.6, 2.2, 3.1... mph. So the console can display speeds to 0.1 mph, but the anemometer itself does not have that level of resolution.

Eric

[AustinTX]

Thank you for your quick replies, Eric and w3drm !!

As you describe it, I am surprised by the lack of resolution of the anemometer since it is a simple rotational switch with a period of 180 degrees (as it rotates, it breaks the signal connectivity twice per full rotation.) It is fully possible for a digital time-based phase counter to approximate better resolution since it is a simple linear scaling of duration of such periods (and not a step function in any ways). Any micro controller could do that kind of work, including the one embedded in the sensor wand of this device (or how do you call the temp/pressure box with a radio emitter?)

I am new to home weather stations; very excited about it and glad to be part of this forum!