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Old September 26th 09, 10:41 PM posted to uk.sci.weather
Stephen Burt[_2_] Stephen Burt[_2_] is offline
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First recorded activity by Weather-Banter: Jun 2009
Posts: 59
Default glass rainfall measure question

On 26 Sep, 22:05, ldpc wrote:
Stephen Burt wrote:
On 25 Sep, 21:10, Scott W wrote:


Evenin' all, could somebody tell me how glass rainfall measures are
calibrated ... ie how many mm of rain from a Snowdon pattern gauge
does it take to make up 1ml of water in a glass measure?


The reason being ordinary glass measures that measure as little as 1mm
are far cheaper to buy than designated rainfall measure-glasses.


Hope that makes sense...


Volume of a cylinder = pi r squared x h


Where r = radius and h - height


For a standard 'five inch' raingaguge funnel, diamter = 127 mm, then r
= 63.5 mm: and for 1 mm of rainfall (= h), then pi r2 h = 63.5 x 63.5
x 1 = 4032 mm3 = 4.0 cm3 (ml)


... and "pi == 1" ;-)

The result should be 1 mm per each 12.668 ml accumulated in that rain gauge.- Hide quoted text -

- Show quoted text -


Pi is, of course, 1.00 only late in the evening after a glass of wine
and when replying to usw questions. At all other times it resumes its
normal value. You are perfectly correct, thanks for spotting my
omission!

--
Stephen Burt
Stratfield Mortimer, Berkshire