AirLink 7210 air quality sensor uploads indoor or outdoor air quality data directly to the WeatherLink Cloud via Wi‐Fi. It can be used as a stand‐alone sensor, or added to your Vantage Pro2, WeatherLink Live or EnviroMonitor system. It can be mounted indoors on a flat surface such as a counter or table top, or on a wall using the included mounting bracket. It can also be used in a protected outdoor location with the included sensor cover. AirLink measures airborne particulate matter (PM) by shining a laser through the air. Particles in the air reflect the laser and the sensor uses the reflection to determine the number and size of particles.