Based on the same counter with the particle theory of light scattered by a unique detection method Will be seized within the unit volume is equivalent to the absolute number of particles as a pulse signal output. Can sense smoke particles produced smoke, dust and other allergic Housing Can detect more than 1 micron or 2.5 micron particles of two small threshold. Small volume, light weight, easy to install. 5V input circuit, to facilitate signal processing. Built-in air generator, free to attract external atmosphere. Maintenance is simple, keeping the long term characteristics of the sensor. Purpose: Air Cleaner, air conditioners, ventilation fans, environmental monitoring