Purple Air

PurpleAir collects measurements of PM2.5 concentrations from a public network of sensors that continuously monitor air quality. Real-time data are transmitted to PurpleAir servers where they are aggregated and made publicly available. Monitors are distributed worldwide, both indoors and outdoors, which gives a comprehensive view of regional air quality. There are almost 12,000, 24-hour averaged, PM2.5 measurements collected from collocated sensors and Federal Reference Method (FRM) or Federal Equivalent Method (FEM) PM2.5 measurements in the U.S. alone (Barkjohn et al., 2021). Studies that have evaluated performance, challenges, and data integration have indicated that, although the system has application for longitudinal ambient PM2.5 measurement, the accuracy of the data may be influenced by the location of the sensors and their installation.