Enviro+ Gas Readings

python gas.py

Produces the readings below but what do these figures actually mean in the real world? Like, what is ‘normal’? This Zero was in the living room at the time.


I think they are pretty meaningless. For example my Oxi sensors start at about 10K and slowly increase to 200K over a few weeks. The nominal value on the data sheet is 20K. They seem to be greatly affected by humidity and air pressure as well.

Have you had any success with other gas sensors on the pi?

No I haven’t tried any others. I have two Enviro+ boards and am somewhat disappointed with them. It is difficult to even get accurate temperature and humidity readings because the RPI, and probably the gas sensors as well, heat the BME280.

I mounted the boards at right angles and have a tiny fan blowing over the back of the PCB. That worked well on the bench but in a case it is very noisy. I think the only way around that is a bigger fan, but that means a much bigger case. A simpler solution might be to mount the BME280 remotely.

The gas sensors need some sort of compensation for temperature, humidity and pressure but I can’t find any information about that.

The particle sensor seems OK but that is a separate unit on a serial bus, so the Enviro+ only contributes a connector.