Measurements for PM, NO2 and CO and readings interpretation

  1. I noticed that NO2/CO eggs give high readings for NO2 and CO (over 1600, 70 respectively) and take around 20 minutes to stabilize at normal levels.
    Question: what is the technical explanation for this behaviour? Can it be avoided?

  2. for the PM egg, what is the interpretation of the PM reading on the device in terms of PM10 and PM2.5? A weighted combination? what ratios?

  1. You are correct that there is a stabilization period for the gas sensors related to the chemistry of the sensor itself. The Egg is designed to be a long running / always on device, and this start is negligible in that configuration. There is no way to avoid this that I’m aware of.

  2. The reading is PM2.5.


Thanks. BTW, the process at is probably stuck. Opensensors seem to have updated their interface and their dashboard sees no activity but the Events section shows activity. I believe Victor added a “cron job to restart the dashboard process every 15 minutes” earlier but I see it stuck for hours now.


Hmmm … .try now. We did a restart.


@AbedKhooli I figured out that the cron job wasn’t actually doing anything, but I’ve fixed that now and there is some evidence that it’s operational now.


I can see it working now. Opensensors are also working on a new dashboard that I hope will help (including mapping) but not done yet (