Martin Rowley wrote:

On 26/08/2012 09:20, Hugh Newbury wrote:
On 26/08/12 08:27, Jeff wrote:
Yesterday we had a colossal rain storm.

My Davis recorded 0.2mm only.

I think the rain must have been so heavy that the tipping bucket
stayed down for the duration of the storm. When the rain eased off
normal operation resumed.

Any body had this happen before?

I would guess that there was between one and two inches in old units
over a period of 20 minutes.

It happened to me the other day, not for the first time, I have to say.
Usually it's because the tipping bucket sticks horizontally with neither
bucket being under the rain gatherer's exit pipe. Then I have to tip it
over to start it again. But of course all the data are lost.

Snow too is a problem, but not generally in August!

Luckily I have a standard raingauge as well.

Hugh

... yes, to be utterly boring (but correct) even with all the fancy stuff
available, it is essential in my view to have some sort of check gauge.
Doesn't have to be a 'standard' copper effort - I've got one of those, but I
also have a 'cheapo' 3 inch alongside to double-check. It needs 'correcting'
- roughly uprating whatever value is given by ~10% - but allowing for that it
gives good service (and has done for many years).


I agree, Martin. My Davis VP consistently measures totals around 15-20% lower
than I measure with a standard 5" copper gauge. Reliance solely on this level
of AWS is unlikely to result in accurate rainfall totals.


--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.