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Rain calibration

From build 3044 the development baton passed to Mark Crossley. Mark has been responsible for all the Builds since. He has made the code available on GitHub. It is Mark's hope that others will join in this development, but at the very least he welcomes your ideas for future developments (see Cumulus MX Development suggestions).

Moderator: mcrossley

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jsel
Posts: 19
Joined: Mon 17 Apr 2017 7:48 pm
Weather Station: Davis VP
Operating System: Pi Zero 2 W bullseye

Rain calibration

Post by jsel »

I have two identical Davis Vantage Pro systems both running CumulusMX on their own Pi, one uses Davis data logger cable, the other a straight serial to USB cable with no logging. In both cases the Console display shows Daily Rain (in mm) 1.27 times larger than shown in the Cumulus display. I can correct Cumulus by changing the rain calibration factor from 1 to 1.27 but why should this be necessary?
Running CumulusMX b3173
John
jsel
Posts: 19
Joined: Mon 17 Apr 2017 7:48 pm
Weather Station: Davis VP
Operating System: Pi Zero 2 W bullseye

Re: Rain calibration

Post by jsel »

Have answered my own question, console sees each seesaw click as 0.01" but Cumulusmx sees each click as 0.2mm instead of 0.254mm hence needs factor of 1.27 to correct.
User avatar
mcrossley
Posts: 12641
Joined: Thu 07 Jan 2010 9:44 pm
Weather Station: Davis VP2/WLL
Operating System: Bullseye Lite rPi
Location: Wilmslow, Cheshire, UK
Contact:

Re: Rain calibration

Post by mcrossley »

Rather than setting a calibration factor, you should set the tipper size to 0.01" under the Davis advanced settings. If you do not set this, CMX infers the default tip size from your units, using the metric tipper size of 0.2mm if you use rainfall in mm, and the imperial 0.001" if you use inches.
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