Does anybody know what the ‘sensor’ and ‘system’ device are user for?

Ok thanks. I am going to order one.

Thanks Mickmack! Now I dare to invest my €80
Since you are using it for more than a year now, how is the accuracy? Does it register little amounts of rain as well?

Hi,
How did this end? Does the Popp Z-rain work as expected? Is the rain amount monitoren correctly in Domoticz?
I am considering to buy the Popp z-rain, but fot €80 I want to be sure that the amount of rain is monitored correctly!

Thanks for letting me know!