What exactly does this mean?

[Dr_G]

Guys,

Still looking at this Nexus weather station - it looks quite good for the money, but I am confused by the wind speed recording description which is:

"Wind Sensor transmission rate: 33s based on three 11s samples"

Is this any good for recording gusts? Presumably effectively it will under-read all gusts since they will be an average of 3 readings? Or does a gust mean the highest of the three samples, therefore if a gust is less than 11s long it will again under-read?

How does this compare with the Vantage Pro method?

Cheers,

Garth.

[Osbourne One-Nil]

I imagine that displays the average over a 33sec period which is, I think, pretty useless for getting the true idea of wind speeds. I believe the VP2 does it every 2.5 seconds.

[Dr_G]

I imagine that displays the average over a 33sec period which is, I think, pretty useless for getting the true idea of wind speeds. I believe the VP2 does it every 2.5 seconds.

O.K., but where am I going to get a VP2 (even cabled would do!) at anything approaching a reasonable price??

[Osbourne One-Nil]

It would take a miracle!

[Dr_G]

It would take a miracle!

Ah well, it is Christmas. You never know.

[Osbourne One-Nil]

No, I mean it. I'm using Parcelforce....it will take a miracle!

[Meteorologica]

"Wind Sensor transmission rate: 33s based on three 11s samples"

As we understand it, it takes a sample over 11 seconds, which is much better than the 128 seconds of the LaCrosse and even the 14 seconds of the WMR928. Then, every 33 seconds it sends the highest of the last three 11 second samples.

[Mondy]

Of course, none of these models will compare to an airport/aerodrome wind censor which, by law, must give true readings.

It's not for nothing major airports have wind sensors all over the place reporting instant gust speeds/direction.

Yer kid on weather station which costs you an arm and a leg is more than likely deceiving you! Good market though!

Get yerself one of these aerdrome wind censors. Go down to your local airport today and nick a wind sensor - what more advice do you need? :smiliz64: :smiliz64:

[Dr_G]

... wind censor which, by law, must give true readings.

So you're telling me even the wind is censored nowadays? Huh, Browns Britain...

[BARRY]

So you're telling me even the wind is censored nowadays? Huh, Browns Britain...

my missus got wind ,try and censor that

[Evening thunder]

Of course, none of these models will compare to an airport/aerodrome wind censor which, by law, must give true readings.

It's not for nothing major airports have wind sensors all over the place reporting instant gust speeds/direction.

Yer kid on weather station which costs you an arm and a leg is more than likely deceiving you! Good market though!

Get yerself one of these aerdrome wind censors. Go down to your local airport today and nick a wind sensor - what more advice do you need?

hmm... ill think about that advice, I hope people won't mind there no longer being any wind readings from Exeter airport on xcweather etc. :lol:

my davis vp2 is by far the best station ive had for measuring wind speed, though of course not nearly as good as the airport ones.

but I think it may be hard to find a reasonable price in this country though.

Edited December 26, 2007 by StormMad26

[Meteorologica]

Of course, none of these models will compare to an airport/aerodrome wind censor which, by law, must give true readings.

If only that was true! Many sensors at official stations are out of calibration. Then of course there is the definition of how you officially measure wind speed and it is definetly not an instantaneous measurement, the official WMO specification is for it to be the average sampled over 2 minutes for land based stations. What most people see as the wind speed is actually the fastest recorded speed over a small sample period but sadly thats not anything like the official standard.

The big difference between airport measurements and home measurements is the site location of the anemometer. On an airfield its mounted clear of any buildings so there is a planar air flow over the instrument producing a much more consistent speed measurement. In a domestic situation the anemometer tends to be mounted above the roof of a building and even though it is exposed to the wind without any obvious obstructions, the apparent sureface layer that the wind blows over is extremely bumpy due to the buildings in an urban environment. These "bumps" produce frictional drag and hence turbulant wind thus making the home based anemometer having to read the wind speed from a very turbulent wind stream.