Rain gauge calibration

This forum provides technical help on how to set up Netatmo Weather Stations for the first time.
chach
Posts: 27
Joined: 25 Jun 2013, 13:14

Re: Rain gauge calibration

Post by chach »

Ich habe ein neuen Regenmesser, nachdem ich ihn Kalibriert habe (200mL Wasser) habe ich festgestellt das ich keine 16,3mm habe sondern nur 3,9mm
ich habe gelesen "You don't have to count the tips. If you pour in 200 mL of water the reading in the web interface must be 16.3 mm/h. Adjust the calibration value accordingly if your reading differs."
aber wie soll ich 16,3mm erreichen ich kann doch nur +- 3 einstellen.
ChmGolf
Posts: 68
Joined: 03 Jun 2014, 19:33

Re: Rain gauge calibration

Post by ChmGolf »

Since the max. value is 150 mm/h (Netatmo website), the maximum volume of water is 1840.5 mL per hour. A volume of 200 mL therefore needs a time of at least 6 min 32 s, otherwise the range is exceeded. To be on the safe side, extend the time. Be sure to continuously drop not faster than approx. 0.5 mL per second at any time to not exceed the range! I did my calibration with continuous dropping of 4 x 50 mL over a period of 4 x 10 min, just to be on the safe side.
falkio
Posts: 76
Joined: 25 Apr 2013, 13:10

Re: Rain gauge calibration

Post by falkio »

Some ideas:

The calibration is needed because no one can make sure that the rain gauge is mounted perfectly even. So the amount of rain in one of the bucked sides which releases the tipping may differ due to the unleveled rain gauge. In addition there may be some production deviations that may also result in different values.

If you flood the rain gauge with 200 ml the bucked doesnt have the chance to tip over 100 times, the tipping may take some time so you have to make sure not to spoil the water. So thats the reason why you have to slowly fill the rain gauge to calibrate.
chach
Posts: 27
Joined: 25 Jun 2013, 13:14

Re: Rain gauge calibration

Post by chach »

hmmm i understand.

on the weekend i drop 200ml in a period of 40min. I hope this is the right way.

Another Question: why do i have to calibrate again if i change the location ?

Regards,
Jan
falkio
Posts: 76
Joined: 25 Apr 2013, 13:10

Re: Rain gauge calibration

Post by falkio »

If you move it and its again not perfectly even there may be some small deviations.
curry767
Posts: 1
Joined: 17 Mar 2015, 06:43

Re: Rain gauge calibration

Post by curry767 »

How slow are you guys pouring the water?

I just tried to the 200ml pour over say 7 minutes and I only get like 6mm. I have double checked and my unit is totally level. My adjustment level based on that test would be something like 5, which from my research is way over the top.

So i'm guessing I'm pouring too fast. What sort of vessel are you guys using to pour?

Thanks for your help.

Cheers

Dave
ChmGolf
Posts: 68
Joined: 03 Jun 2014, 19:33

Re: Rain gauge calibration

Post by ChmGolf »

I used a burette from the chem lab: https://en.wikipedia.org/wiki/Burette
RolfB
Posts: 1
Joined: 26 Aug 2015, 18:53

Re: Rain gauge calibration

Post by RolfB »

Hello, i just don't understand it. I putted in exactly 200 ml very slowly (10 minutes). I counted 155 switches. So according to Netatmo, i calculated 200 / 155 = 1,29. This value i used, and the app shows 9,7 mm of rain.
But when i calculate 200/(12,5/2)^2*Pi it should be 16,3 mm of rain. Can somebody please explain to me, what is right and what is wrong?
Thank you very much
jfkm
Posts: 110
Joined: 24 Nov 2015, 17:40

Re: Rain gauge calibration

Post by jfkm »

I find that the calibration is really random(unpredictable). I tried by overturning 100ML (indication Netatmo), then 200 ml.

In taste in enjoy(taste), over approximately 30 minutes every time..

To obtain a value of 16,3 on Web (for 200 Ml) I am obliged to calibrate in 1.67!! Is very different from the calibration manufacture 1,259...

What are your values of calibration?

Thank you!
wokkeltje
Posts: 12
Joined: 13 May 2016, 21:28

Re: Rain gauge calibration

Post by wokkeltje »

How do you remove the data of the measurements during calibration.
If I calibrate the device and pour in 200ml, this will be reported to the weathermap and I don't want this.

There is a feature to remove data, but this doesn't seem to work for the raingauge. if I remove the data from the outdoor module, also rain gauge data is removed, but this I don't want to do.

any more recent calibration tips?
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