Rain Gauge Calibration

[bambou55]

Hi all,

I have a problem with the calibration. Theoricaly, if I put 100 ml (or 100 g) of water in the rain gauge, slowly, I shoud have a rain value of 8.1 mm.

But, I have only 6.1 mm with the calibratin setting of 2, the maximum I can reach...

If I count the number of "hit", 72 and divide by 100, the calibration factor is 1.39 and the rain value is only 4.2mm !

What is wrong, what are your experience ?

Thanks

[wopper]

Got the same here, you should put the water slower info the gauge 100ml should take at least 10 minutes. The my unit was correct at factory settings 1,25 and before that i used 2 because of the same results as you.

[bambou55]

thanks for the reply...

We had a lot of rain last 24 hour. I put a cylindrical glass next to the rain gauge and measured 34 mm of water.

To have this result on the Netatmo display, I have to use a calibration of 1.75.

[ChmGolf]

I today determined a calibration factor of 1.65 for my station.

[JBaguley]

I got 1.72 for mine. Poured the water in slowly and did many attempts to get a good spread of data. This seems to tie in with the others here.

What you don't want is it spilling over the cup before it tips, but since you cannot see inside while pouring this is difficult!

[Patatorz]

Just tested the calibration today and counted between 68 to 73 counts so with a correction factor around 1.418
I made the count around 5 times and it took me around 1 min to drop 100ml...

[biondi]

I did 3 tests - 84, 84 and 81 and just averaged them out. Not a whole lot different to what it was set to.

[ChmGolf]

Just tested the calibration today and counted between 68 to 73 counts so with a correction factor around 1.418
I made the count around 5 times and it took me around 1 min to drop 100ml...

The rain gauge only works up to 150 mm/h (see specifications, Netatmo site). If you drop 100 mL within 60 s you cause a virtual rainfall of about 489 mm/h, which well exceeds the range. Therefore I guess, your calibration factor may be wrong. For 100 mL you need at least 3 min 16 s to be within the range, but I would take more time (e.g. 5 - 10 min) to be on the safe side.