The market heat for air purifiers has been increasing over the past two years, showing good development prospects. This is mainly due to socio-economic development, increasing urban pollution, and people's pursuit of a healthy, high-quality life. For various types of air purifiers or related products, the basic principle can be divided into three steps: detection, purification, and release. That is, the air purifier detects pollutants in the indoor air, then filters and purifies them, and finally exhausts the filtered pollution-free air, thereby achieving the effect of purifying the air.

At this point, you should have noticed that the air purifier only starts operating after detecting pollutants; in other words, pollutants are the switch for purification. The "probe" inside the air purifier acts as its "eyes." If this "probe" is not sensitive, the purification function of the air purifier cannot be effectively utilized, no matter how good it is. Only by promptly perceiving changes in indoor air quality, passing information to the user in a timely manner, and automatically adjusting settings, can the cleaning and purification efficiency be maximized.

The probe inside the air purifier is a dust sensor, which utilizes the principle of light scattering. When light shines on suspended particles in the air, it produces scattering. Simultaneously, a detector receives the scattered light at a specific angle. The resulting photocurrent is amplified to obtain a curve corresponding to the particles and the electrical signal. After the microprocessor collects the data, a series of algorithms are used to determine the mass of particles of different sizes per unit volume.

The laser dust sensor LD09 is a high-precision particulate matter concentration sensor based on the Laser MIE Scattering theory. It can continuously collect and calculate the number of suspended particles of different sizes in the air per unit volume—namely, the particle concentration distribution—which is then converted into mass concentration and output via a universal digital interface. This sensor can be embedded in various instruments or environment-improvement equipment related to the concentration of suspended particulate matter in the air to provide timely and accurate concentration data.