New Airgradient One units only reading PM data intermittantly

[syenta]

Hi all,

If I’m posting this in the wrong spot, my apologies.
I’ve had a look through the forum and can’t find anything that exactly covers my situation.

I have two Airgradient One indoor sensors, brand new, preassembled. Set them both up as far as I cant tell correctly. I also took them both outside to calibrate their CO2 sensors.

Neither unit will consistently show any of their PM sensor data. both will read all PM data as zero almost all the time, except occasionally and for no reason I can discern, one of the units will show reasonable readings on the dashboard. It gets maybe a half a day of readings, and then it goes back to reading 0 again.

Is there something obvious I’m missing here? do I need to open them to take a cover off the sensor or is there a PM sensor calibration that needs to happen?

[Achim_AirGradient]

It could be related to this issue.
Correlation between older and newer PM Sensors - #2 by Achim_AirGradient

To know more, can you please post some charts with the PM in ug/m3 and the PM003 count?

Thanks

[syenta]

Here are some screenshots of the 0.3um, 1um, 2.5um and 10um sensors. The 0.3um seems to be working as expected but the other 3 only work intermittently and with seemingly very poor accuracy. The readings are almost identical for the other Air gradient box that is setup immediately next to this one.

The room these are in is a workshop and is definitely not that clean as to read zero on pm1 most of the time. I also tried downgrading the firmware on one of the boxes and that doesn’t seem to have changed anything.