rain calibration hp2551

[sevak]

Hello everyone,
because i found the rain results not really accurate, i started to investigate about our rain buckets.
So if it can be usefull to others, we have a surface of captation of 100cm2 (+-) with a diameter of 11.285cm. it means that when we have 10ml, it s equal to 1mm. the buckets have a 2.5ml volume= 0.25mm.So we need 4 times the move of the bucket to get 1 mm.normally... But with a graduated rain gauge, it s quite different of 1 to 2 mm less for 10mm in the gauge (like 8.5mm in ecowitt). so im still investigating on this...if you have some ideas...

[HansR]

I use a manual Hellmann rain gauge (+/- € 80,-) to verify my automatic (Ecowitt) measurements.
This shows me that the deviation on average is not so very large.

The reading accuracy of the Hellmann rain gauge is 0.1 (maybe 0.2) mm and has a maximum of 25 mm.
At least it showed me that I can accept the automatic measurement as true. The deviation definitely for me is not 2 mm per 10 mm. Accuracy of rain gauges is dependent on a lot of things, reading the scale is one of them, temperature dependency is another (deformation of the rain gauge). But wind also plays a major role (the angle of attack).

See foto's and data below.

Schermafbeelding 2024-01-10 140412.png

Schermafbeelding 2024-01-10 140435.png

[sevak]

Hello Hans, thanks for your input. I try to make my own homemade rain Gauge, to do the same kind of reports and calculation. But your results are quite reassuring on the quality of the ecowitt! i was also thinking to make the receptor bigger for more accuracy.
I also read a lot on the subject, and the conclusion is, there is always a disperancy with the results even with 2 or 5 SPIEA or pierron, or whatever,... the rain is not the same everywhere anyway. We just can be as close as possible from reality...