You’re welcome, Rob.
As an old hardware designer I do agree with you. In fact all this must not have been an easy compromise, keeping also in mind the cost of the product.
I suggest to deepen the analysis by performing independent tests in different ambients and with different PMs. It should give a more accurate idea of how much the particulate measurements are influenced when the device is under full sun, and what are the best solutions to mitigate these effects.
The single experience I made tells me that with the current device a full sun exposure should be avoided. Temperature and humidity readings become totally wrong, of course. But also the PM measurements seem to be seriously affected (reduced, as if the air was much cleaner). At least, this is what happened at the low PM levels I recorded.
Anyway, and waiting for some news and suggestions, I’ve decided to keep my Airnote permanently away from direct sunlight. To survive, it will get a 5 V supply through an USB cable.
Best regards,
Alberto