This Sharp dust sensor operates by an optical sensing system. A diagonally arranged infrared emitting diode and a phototransistor detect the reflected light of dust in the air. It has the ability to detect very fine particles, including cigarette smoke. It can even distinguish the smoke from house dust by measuring the pulse pattern of output voltage.
Use this handy dust sensor to measure dust in the air. It's applications range from air purifiers to air conditioners, and of course, air monitors.
Links and Datasheets
For the schematics, graphs, and full specifications, please refer to the Datasheet