How to add a rain sensor ?

[Dave21w]

My rain sensor also contains a temp sensor, when added to Domoticz the temp is fine but the rain level shows up as a humidity value and i can't figure out how to get it to be seen correctly, any ideas anyone?

The label on the bottom says:

R-NZ
Aercus Instruments
Freq 433Mhz
Model KW9015
Batch 160915

Its one of those that has a little see saw type arrangement inside that rocks back and forth as the cups on the end fill with water.

My RFXCom see it as a "SubType" Alecto device

TIA
Dave