On 2014-01-25 15:37:46 +0000, Vidcapper said:

On 25/01/2014 11:06, Norman wrote:
Vidcapper wrote:

Would the mounting poll being slightly off-vertical (presumably knocked that
way by the recent strong winds) adversely affect recorded totals?

Presumably the buckets would each tip with different amounts of water, but
wouldn't they offset each other?


I don't know how much difference it might make. In general, though, the Davis
VP raingauges seem to under-read compared to a standard 5-inch manual gauge.
Mine under-reads by 15-20%. It's the most disappointing feature of the Davis
VP. Undoubtedly, one of the reasons is that it is usually located some distance
above the ground whereas the standard 5-inch gauge is usually at ground level.


IRO rain gauge heights, I've found this interesting, if old, article :

http://www.hydrologynz.org.nz/downlo...v9_2_Green.pdf


I attempted some experiments last summer with my VP gauge, and my
conclusions were that the reed switch was not registering every tip for
some reason. Whether it was such a short voltage spike I do not know,
but checking the base station total after 10 tips of the gauge, I had
readings of mainly 6 to 8, one of 9 - but never the full 10.

I had intended to replace the reed switch, but without a knowledge of
electronics, plus an untrustworthy soldering technique I was worried
that I would do more harm than good.