Continuous Ambient Air Quality Monitoring Station
Also called: CAAQMS · Topic: Geographical Issues: Pollution, Urban Waste, Slums and Land Degradation · NCERT: Beyond NCERT
Meaning
A Continuous Ambient Air Quality Monitoring Station (CAAQMS) is a fixed station that measures the quality of the outdoor air we breathe, all day and all night. "Ambient" means the general outdoor air, not the smoke coming out of one chimney. Automatic instruments in the station measure pollutants such as PM2.5, PM10, NO₂, SO₂, CO and ozone. They send readings in real time, so the public can see the air quality almost as it changes. These readings feed the National Air Quality Index (AQI), which turns eight pollutants into one number. AQI levels then decide when steps such as the Graded Response Action Plan (GRAP) are started. A daily reading is valid only if the station sends enough data (at least 16 hours a day), and the station must be placed as CPCB norms require.
Example
In 2026, Delhi-NCR had 111 working CAAQMS, installed by CPCB and the state pollution control boards together with IMD. Their data goes into the PAVAN-I3C platform of the Commission for Air Quality Management, which uses it to track Delhi's winter smog and decide GRAP stages.
Don't confuse with
- Manual monitoring station: staff collect air samples by hand and test them later, so the results are not live.
- Online Continuous Emission Monitoring System (OCEMS): it measures pollution at the source, inside an industrial stack, not in the open outdoor air.