So most air quality monitors need to be "cleaned" and recalibrated by cycling them in a clean air enviro for a few mins, especially if they have been exposed to

So most air quality monitors need to be "cleaned" and recalibrated by cycling them in a clean air enviro for a few mins, especially if they have been exposed to high levels of pollutants otherwise they may be "off" in their measurements. Anyhow, it's worth giving them a try it seems.