[werk_ag]

Hi Jim,

I also had never seen a zero reading, this is why I haven't prevented that possibility before.

Unfortunatelly I haven't any PMS7003 at hand. If I had, I would have written a simple test software for the PMS7003, that will try to read the sensor at each 10 seconds, reporting the successful and failed attempts. That could help in you to understand those zero readings.
Anyway, even without the sensor I will try to write it.