"Phil Layton" wrote in message
...

"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
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Always bear in mind that AWS rain-gauges typically collect up
to 10% less rain than a standard manual gauge. Sometimes the
difference is even greater. I'd always recommend having a
manual gauge alongside an AWS one.

Why is that - is it just a calibration thing ? I often have to amend the
AWS figure after the event with the rain-guage value.

Actually, Phil, probably not calibration at all. I have a top-of-the-
range one at Hampstead, but it still catches 9% less than the manual
gauge. As far as I can gather, the main problems are out-splash (it
doesn't have a raised outer rim) and inefficient tipping of the
tipping-bucket mechanism. Poor design sums it up best, I think.

Philip