Does rainrate change if you use bigger funnel?

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WS Grave
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Does rainrate change if you use bigger funnel?

Post by WS Grave » Thu Jul 15, 2010 10:51 pm

I'm wondering, does the rainrate change if you use a bigger funnel for your rain gauge?
Or does that have no effect on the calculation of the rainrate!?

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Re: Does rainrate change if you use bigger funnel?

Post by skyewright » Fri Jul 16, 2010 11:51 am

WS Grave wrote:I'm wondering, does the rainrate change if you use a bigger funnel for your rain gauge?
Or does that have no effect on the calculation of the rainrate!?
If you add a bigger funnel you need to provide a calibration factor on the Settings page of Meteohub.

e.g. On my WMR928 I have a funnel that has 4 times the original area, so on the Settings page I have 2 entries for that rain gauge, one applies a factor of 0.25 to "Total Fall" and the other applies a factor of 0.25 to "Rate", with both factors being effective from the date and time when I fitted the funnel.

The WMR928 console itself is unaware of the funnel, so it shows rain as 4 times more than it actually is, so I just need to do a mental calculation if I look at that.

PS. It may be that there are weather station consoles that allow you to set a calibration factor there; if that was the case then you wouldn't need to enter a factor in Meteohub as well.

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Re: Does rainrate change if you use bigger funnel?

Post by WS Grave » Sat Jul 17, 2010 6:08 am

Thanks for the confirmation Skyewright.
I was wondering about the high values messured during a recent storm :)

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