Mitsubishi Electric demonstrates the use of light to determine the air quality sensor

Mitsubishi Motors, February 17, 2016 R & D results released to the news media with "Air Quality Sensor" that identifies PM2.5, pollen and dust.

The air quality sensor irradiates laser light after inhaling air that may contain dust such as PM2.5, and recognizes the type of dust based on the scattered light. Two types of light detectors perpendicular to the direction of laser irradiation are used. When there is no dust will not produce scattered light, while the larger the particle size of dust, the intensity of scattered light will become larger. The intensity of scattered light is detected using one of two light detectors.

In addition, the scattered light changes its polarization characteristics due to the shape of the dust, thereby making it possible to distinguish whether the dust particles are close to spherical or non-spherical. Another photodetector uses two detectors. The two detectors are equipped with two types of polarization filters with different vibration directions. The polarization characteristics can be estimated by the intensity ratio of two detectors. Since the size and shape of the dust and the dust can be judged from the intensity and polarization characteristics of the scattered light, it is possible to distinguish whether the dust particles are PM2.5 or pollen.

Mitsubishi Electric performed a demonstration that air quality sensors were aspirated into the dust and then displayed the distribution of various types of dust as well as the start of the linked air purifier.