The new, easy to use sensor provides high accuracy air quality measurement by detecting PM ‘particle matters’ in the air. The sensor integrates a laser diode which emits light to the air in the detection area and a photo diode to detect scattering light correlated to the actual floating particles in the air. An integrated MCU then analyses the wave profile from the photo diode by optimistic algorithm, then outputs a converted mass-density (μg/m3) through I2C & UART interface.