Air quality sensors are becoming more common tools for tracking environmental conditions such as allergens, indoor pollutants, and humidity. These devices are frequently used alongside air purifiers to enhance indoor air quality. Various models are available, each offering different features and capabilities suited to specific needs and environments. The Netatmo Smart Weather Station is often cited as a benchmark in the field, merging the functions of a weather station with those of an air quality sensor. It measures temperature, air humidity, CO2 levels, and sound levels. Compatible with Amazon Alexa, Apple HomeKit, and Google Home, the station can be expanded with accessories such as an anemometer and a rain gauge. It is appreciated for its refined design and frequent promotional offers. The Airthings View Plus is suggested for monitoring radon, a radioactive gas found in certain regions like Brittany, Auvergne, and Corsica. This device includes seven sensors, one of which detects radon, and also measures temperature, humidity, atmospheric pressure, VOCs, CO2, PM2.5, and radon. It connects directly to a Wi-Fi network and can serve as a central hub for other Airthings sensors. However, it needs a week for calibration and has a relatively high price of 299 euros. The Eve Room is designed for users of Apple HomeKit, offering measurements of temperature, humidity, and VOCs. It is compatible with iOS devices and requires a HomePod or Apple TV 4th generation for network connectivity. Although it does not measure CO2, it is praised for its elegant design and seamless integration with Apple products. The Amazon Smart Air Quality Monitor is ideal for homes with Alexa devices, providing a range of measurements including PM2.5, VOCs, CO, humidity, and temperature. It is noted for its affordability at 79.99 euros and includes a colored LED indicator for air quality status. It can be connected to air purifiers and sends notifications if air quality worsens. Air quality sensors typically measure CO2, humidity, and temperature, with some models also detecting VOCs, PM2.5, and radon. Elevated CO2 levels can signal the need for better ventilation, while VOCs and PM2.5 are harmful pollutants. Radon, a radioactive gas associated with lung cancer, is more common in specific geographic areas. Enhancing air quality can be achieved through regular ventilation, maintaining mechanical ventilation systems, and using air purifiers.