"xmetman" wrote in message
...

I suppose the Vantage Pro just collects 1 minute mean speeds and graphs
those values in its own LCD display, and it's down to the display software
on the PC to take the average of 10 of those one-minute values to produce a
10 minute mean. A one minute mean of 67 mph would be significantly higher
than a 10 minute mean (~x1.2 or more higher).
====================

Is it a VP you have (aka VP1 nowadays) or a VP2? If so, it might explain the
apparent default to small cups - that's not the been the default for a long
time. (Not that it makes a huge difference, it's just a different
second-order LUT that's applied for correcting speed vs direction AIUI to
account for effects of the anemometer arm geometry.

But why would you suppose that it collects 1-min means rather than averaging
out the full set of 2.5 sec gust values that are the values actually
measured?