# How can I test the Air Quality?

I'm unable to find good sources to make myself an AQI(Air quality Index) measuring device. All I was able to find was the way it is calculated in different regions. But I need some help with the technology used to measure the concentrations of different pollutants like SO2, NOx, PM10, PM2.5, etc.

Are there any good papers or patents on the technology used to measure the AQI?

Any help is appreciated. Thanks.