[Weather] conversion help

[Steinar Midtskogen]

[Tim Sailer]

> I've wondered about doing that to my Lacrosse gauge. It would register
> very, very light rain. I'd just be worried of wind damage for a big
> funnel. Has anyone modified their gauge for better resolution?

Mine ( http://voksenlia.net/met/prec.php ) has a funnel about 20 cm
across, and has been calibrated to 0.115 mm per tip.  Of course, an
even bigger orifice is possible and could offer even better accuracy,
but there are some disadvantages:

* It would require a sturdy mount to avoid wind damage.

* In very heavy rain it would be inaccurate because the buckets refill
  too fast.  E.g. if the rain rate is 100 mm/hr and there is 0.02 mm
  per tip, there will be almost 1.4 tips per second.

* A heater devince for melting snow would require a few hundred W,
  making it costly and it would be difficult to use low voltage.


Professional equipment often uses a single bucket (without tipping
buckets) willed with antifreeze (which will melt snow) and some oil
(to prevent evaporation), and it will determine precipitation by
weight.  The bucket needs to be emptied and refilled a few times a
year, though.  Has anyone attempted to make a 1-wire based gauge of
this design?

-- 
Steinar