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Re: Another rain calibration experience

Posted: Fri 05 Mar 2010 10:32 pm
by aaardvaark
Aha! Interesting new insight today after recent rain. This rain was the steady, not too heavy, no wind at all kind of rain. And here's my calibrations from three measurements with that kind of rain: 0.99, 1.01, 1.02. In other words, the tipping bucket itself is as accurate as you could ask for. So other effects due to collection funnel dynamics must be responsible for my previous cal figure of 1.2 or 1.17. i.e. wind or possibly the effect of heavier rain, but I think wind.

So now I'll keep an eye on the cal in different kinds of rain and see if I can pick a pattern. Higher vertical sides seems the trick, as Gina and others have discovered.

Re: Another rain calibration experience

Posted: Sat 06 Mar 2010 12:58 am
by beteljuice
As you yourself said earlier, height makes a difference - and you are on the second floor :o

There are probably times when your location experiences very light rain being 'suspended' or even travelling upward next to the building !

Not much you can do about that other than move or put it on the roof :cry:

Re: Another rain calibration experience

Posted: Sat 06 Mar 2010 2:53 am
by aaardvaark
Yes am aware of the height problem. One set of measurement variables relates to the siting of the gauges, the other to the collection gauge characteristics. In my current measurements I'm comparing two measurements made at the same location, same height, right beside each other, so only interested in the difference in how wind or whatever affects the rain that gets into each gauge, not the site effects.

Re: Another rain calibration experience

Posted: Sat 06 Mar 2010 9:21 am
by EvilV
aaardvaark wrote: From where we stand, rain is all good, but sure I could change my mind if stuck in lots of it for too long.

Thirteen to fifteen inches inches fell on the English Lake District on 19th November 2009

http://www.youtube.com/watch?v=QPeByrpU ... re=related


http://www.youtube.com/watch?v=X9TObBfg ... ature=fvwp