Uni-T A25D PM2,5-monitorerUni T A25D PM2. 5 Monitors The A25 Series PM2. 5 is a compact air quality monitor designed for everyday use in a variety of settingsfrom homes to offices and commercial spaces. The device focuses on measuring PM2. 5 concentrations, allowing you to quickly assess air quality and take action when it deteriorates. Built in features, such as audible and visual alarms and automatic baseline calibration, make the meter easy to use and require no specialized