Thanks, Philip, I didn't realise that it was so widespread a problem.
I would like to point out that I only measure rain in the 5" one a week. Do you think that,
besides the turbulence problem, there could be some systematic errors in reading small amounts
in a 5" measuring glass?
--
Roy Avis
+++++++++++++++++
"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
...
"Roy Avis" wrote :

I have a standard 5 " gauge a few metres from my Vantage Pro 2, and up to 0900 today I have
recorded 95.3mm in the 5" and 93.8 via the VP2 tipping bucket.
This 1.5 mm diffence has been about the same since the rains of mid January, so it would seem
that some tips may be lost during high rain rates.
However, this difference is only about 1.5%. Your 15% difference suggest a more fundamental
problem!

Roy, most of the difference comes from the different exposure of
the rain-gauges. If you are achieving only a 1.5% shortfall in an
elevated gauge you are doing exceptionally well. I'd be interested
to see if you maintain that figure. Most users who have made a
systematic check over a long period report a loss between 5
and 15%, the variation indicating differences in the effects of
turbulent air flow around the elevated AWS gauge.

Philip