Netatmo rain gauge values?

[reneklomp]

Guys,

I have been using a Netatmo rain gauge for some time now. After some initial issues with the device itself (was returned and got a new one) it looks sort of OK now. Anyway, that's not the point now...
I am reading values from the device in the Weather tab that looks OK as far as I can tell:

The device 'Rain' in the Weather tab shows seemingly correct values like:
Rain 16.7 mm; Rate: 16.1 mm/h (yes, it was raining quite a bit when I looked at these)

Now I am trying to read these (s)values from the device in a Lua script. However, when you e.g. look at the device underneath Setup->Devices the values are not what I had expected:
Type = Rain ; SubType = TFA ; Data = 1610;258.4

Now it looks like the 1st value is consistent (with a factor of 100) with the Rain Rate as reported in the Device item.
But how do I get to the other value...? What is the device reporting with 258.4 ??? And how does Domoticz get to the number of 16.7 mm?
Is this the total rain for today?

Thanks, Rene.

PS. I am using Version: 3.8153