Air Quality Sensor

An air quality sensor is a device used to detect and measure the concentration of pollutants in the air, which is widely used in environmental monitoring, industrial safety, smart home and other fields. These sensors detect various contaminants such as particulate matter (PM2.5 and PM10), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and volatile organic compounds (VOCs).

Working Principle

Air quality sensors function based on various detection methods tailored to specific pollutants. Here are some of the most common mechanisms:

• Chemiresistors: These indoor air quality sensors detect gases by measuring changes in electrical resistance across a chemically sensitive material when exposed to certain gases. Commonly used for detecting volatile organic compounds (VOCs).
• Electrochemical Sensors: These are used for detecting specific gases like carbon monoxide, nitrogen dioxide, and sulfur dioxide. They operate by producing a chemical reaction that generates an electric current proportional to the concentration of the gas.
• Infrared Sensors: These measure gas concentrations based on the absorption of infrared light at specific wavelengths by different gases. They are particularly effective for detecting carbon dioxide (CO2).
• Optical Particle Counters (OPC): These PM2.5 sensors use light scattering methods to count and size particulate matter such as PM2.5 and PM10 in the air.
• Metal Oxide Semiconductors (MOS): Used for detecting a wide range of gases, these sensors change their electrical conductivity in the presence of gases, with sensitivity to temperature adjustments.

There are various types of air quality sensors, particulate matter sensors are specialized in detecting the concentration of particles such as PM1.0, PM2.5, PM10, etc.; gas sensors are capable of detecting a variety of harmful gases such as carbon monoxide, sulfur dioxide, nitrogen dioxide, etc.; and comprehensive air quality sensors are integrated with a wide range of detecting functions, capable of detecting a variety of pollutants and environmental parameters at the same time, and giving comprehensive air quality indicators.

Why Air Quality Sensors are Important?

"Indoor air pollution" is the "soot pollution", "photochemical smog pollution", after the emergence of the third environmental pollution. American experts found that there are more than 500 kinds of volatile organic compounds in indoor air, of which there are more than 20 kinds of carcinogenic substances and more than 200 kinds of disease-causing viruses. The major hazards are: radon, formaldehyde, benzene, ammonia and ester, trichloroethylene and so on. A large number of alarming facts confirm that indoor air pollution has become a hazard to human health "invisible killer", but also become a common concern of countries around the world. According to statistics, nearly half of the world's people in the indoor air pollution, indoor environmental pollution has caused 35.7% of respiratory diseases, 22% of chronic lung disease and 15% of tracheitis, bronchitis and lung cancer. That's why it's necessary to use air quality sensors to test the air.

Application

Air quality sensors have a wide range of applications. In the field of environmental monitoring, a large number of sensors are deployed in cities to monitor the concentration of atmospheric pollutants in real time and provide data for environmental assessment and policy formulation. In industrial production, chemical and petroleum industries use it to monitor exhaust emissions and ensure environmental safety. In indoor environment detection, air quality sensors are installed in homes, offices and other places to monitor formaldehyde, carbon dioxide, etc. to create a healthy indoor environment. In the field of intelligent transportation, sensors next to roads or on vehicles can analyze the relationship between traffic and air pollution, providing reference for traffic management and drivers.