What do PurpleAir sensors measure?
PurpleAir sensors measure airborne particulate matter (PM). Particulate matter describes solid particles suspended in air including dust, smoke, and other organic and inorganic particles. PurpleAir sensors use laser particle counters to count the number of particles by particle sizes 0.3, 0.5, 1, 2.5, 5, and 10 μm, and uses the count data to calculate mass concentrations of PM1.0, PM2.5, and PM10.
How do PurpleAir sensors work?
PurpleAir sensors use laser counters to measure particulate matter in real time. A laser counter uses a fan to draw a sample of air past a laser beam. Any particles in the air will reflect some light from the laser beam onto a detection plate, like dust shimmering in a sunbeam. The reflection is measured as a pulse by the detection plate and the length of the pulse determines the size of the particle and the number of pulses determines the particle count. The PM1.0, PM2.5, and PM10 mass concentrations are calculated from these particle counts.
The Borough has 3 sensors in the downtown area.
For more information and to view the map of the actual locations of the sensors, please visit the Purple Air webpage Here