• What is AQI Sensor or Air Quality Index Sensor?
  

• The Air Quality Index (AQI) is a standardized measurement used to communicate how polluted or clean the air is in a specific area at a given time. It provides an easily understandable way to convey information about air quality to the public.

  AQI typically takes into account several major air pollutants regulated by environmental agencies worldwide, such as ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2). Each pollutant has its own scale and threshold levels that determine the AQI value.

  The AQI scale ranges from 0 to 500, with specific categories indicating the level of health concern associated with the air quality:

  • 0 to 150: Normal to Moderately Polluted-This range encompasses air quality conditions that are considered acceptable for most individuals, with occasional concerns for sensitive groups in the higher end of the scale.
  • 151 to 200: Poor- Everyone may start to experience health effects, and sensitive groups are more likely to be significantly affected.
  • 201 to 300: Very bad - Health warnings of emergency conditions. The entire population is likely to be affected, and serious health effects may arise.
  • 301 to 500: Toxic - Health alert: everyone may experience more serious health effects due to the extremely poor air quality.
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The Air Quality Monitoring System operates by utilizing sensors to detect environmental parameters like gas levels, temperature, and humidity. Specifically, analog readings from the gas sensor, connected to an Arduino's analog pin, provide data on the air quality. These readings are mapped to predefined thresholds, categorizing the air quality as "Good," "Poor," "Very Bad," or "Toxic." Simultaneously, a dht11  measures humidity and temperature. The collected data is displayed in real-time on an OLED screen using the Adafruit libraries. By continuously monitoring these parameters, the system offers a snapshot of air quality conditions, enabling users to assess and respond to changes in their environment.

Arduino Air Quality Monitoring System Circuit Diagram

The complete air quality monitoring system project connection will be as follows with an OLED, DHT11 and MQ135 gas sensor connected to Arduino Uno on a breadboard.