This Wearable Pollution Monitor Detects How Dirty Your Air Is

Thanks to the development of inexpensive sensors, several products claiming to test air quality have hit the market in recent years. Flow ($179), developed by Paris-based Plume Labs SAS, is a portable pollution sensor that’s encased in aluminum punched with a pattern of asymmetric holes for “360 air intake.” The device uses a tiny fan to suck in air as a combination of lasers and membranes detects what’s in it. An app introduced with the device in September breaks the measurements down into particulate matter (PM), nitrogen dioxide (NO2), and volatile organic compounds (VOCs) in real time.

· The white-plastic casing of the $249 Airbeam2, shaped like a cartoon ghost, houses PM, humidity, and temperature sensors and works with an Android-only app. At about 5 by 4 inches, it’s designed for on-the-go use but is much larger than other devices.