Vantage Vue wind speed about half expected value

[martinu]

I've got my Vantage Vue sensor mounted about 20 feet up a pole. There is a hedge which is about 15 feet high, about 30 feet horizontally NW of the pole. Our two-storey house is about 50 feet away SW. There are open fields for about 1/2 mile in an arc to the N, E and S.

I've noticed ever since I had the VV that the wind speed readings (average and gust) that the VV console and Cumulus record are about half the values that are typically recorded by published weather sites. Up to now I've tended to mentally double whatever readings are recorded, though I've just discovered (belatedly!) that Cumulus can apply a scale factor.

I remember when I first set up the VV console that one of the setup questions is the type of anemometer cup. I answered this sensibly (I chose "3 cup" as opposed to "4 cup" since this is the number of cups that my anemometer has). But I'm wondering whether I chose correctly.

Has anyone else had problems with the anemometer consistently under-reading and giving readings which are about half what you'd expect?

My VV is the standard one sold in the UK, eg with a 0.2 mm rainfall tipping spoon as opposed the US one calibrated in inches. The CE-marked label on the sensor unit says Model No 6250UK. I don't know whether this helps identify the exact anemometer supplied and therefore the correct setting on the VV console during the initial setup. It was bought in December 2012 if that helps to give the revision sold at that time.

It may be that the readings are low because of shielding from the hedge and the house (can't do much about that!) but I want to check for mis-calibration as a possibility.

[martinu]

Ah. I may be barking up the wrong tree about calibration. I mis-remembered the sequence of questions that I was asked when originally setting up the Vantage Vue. If I select the type of sensor unit to be Vue ISS I don't get asked about cups; you only get asked about cup size if you select VP2 or WIND. ("Cup size" sounds more like a question when choosing a bra!!!! )

So it looks as if there's nothing to configure (or mis-configure!) for the Vantage Vue. Maybe the low wind speed readings are simply due to the shielding effect of the house.

However I'd still be interested to know if anyone else has had problems with the anemometer consistently under-reading and giving readings which are about half what you'd expect.

[grandrouge]

See http://wiki.sandaysoft.com/a/Wind_measurement

I increased my Vantage Vue multiplier as my unit is at 2m in the middle of a field with no obstacles for at least 50m in all directions.