±0.3ppm (±600-850 ug/m3, depending on the pollutant) means that AQI for each individual pollutant (and for air quality in general) can be from "very low" all the way to "very high".
What do you suggest we do with these results?
Should we use them only to observe trends?
Is it possible to normalize the results?
For example we compare measurements made by official AQI station and Waspmote and make a "corrective factor" that we use to multiply our results with? E.g. in measurements from last week official AQI station measured 43.7 ug/m3 and we measured 669.87 ug/m3. Could we multiply our future readings with 43.7/669.87 and get something meaningful from it? Will this ratio always be the same? What if NO2 goes up 30 ug/m3 - we're not going to get +30 but +2 because of that factor... Should we subtract the numbers, not divide them? ...?
Do you have some information how other customers process information from electrochemical sensors since they clearly can't be use for calculating AQI "out of the box"?
Aren't these sensors temperature compensated? I see that one of the inputs into the formula is current temperature read from BME280.