Pretty sure that Netatmo measures only CO2, not PM2.5. There’s no mention of PM2.5 on the link you posted. Also, to properly calibrate the Netatmo needs to be

Pretty sure that Netatmo measures only CO2, not PM2.5. There’s no mention of PM2.5 on the link you posted. Also, to properly calibrate the Netatmo needs to be exposed to essentially outside air once a week as it takes the weekly lower bound as its reference point. More sophisticated sensors don’t have this limitation.