Update: 2019-12-11 17:41 Source: LUFTMY
Fine particles are also known as fine particles, fine particles and PM2.5. Fine particles refer to particles with an equivalent aerodynamic diameter of less than or equal to 2.5 microns in the ambient air. We all know that PM2.5 particles do great harm to human body. Particles enter human body through human respiratory system, directly affect lungs, and even small particles can enter blood and other organs directly.
PM2.5 fine particles refer to particles with aerodynamic equivalent diameter of 2.5 μ m or less in ambient air. It can be suspended in the air for a long time. The higher the concentration in the air, the more serious the air pollution. Although PM2.5 is only a small part of the earth's atmospheric composition, it has a significant impact on air quality and visibility. Compared with the coarser atmospheric particles, PM2.5 particles are small in size, large in area, strong in activity and easy to attach to toxic and harmful substances, such as heavy metals, microorganisms, etc.
Ash weather caused by fine particles is more harmful to human health than dust storm. Particles with a particle size of 10 microns or larger will be blocked outside the human nose; particles with a particle size between 2.5 microns and 10 microns can enter the upper respiratory tract, but some can be discharged through phlegm, etc., or through the nasal cavity. However, the fine particles with particle size less than 2.5 μ m are equivalent to one tenth of human hair, and are not easy to block. When inhaled, it enters the bronchi directly, interferes with the gas exchange in the lungs, and causes diseases including asthma, including bronchitis and cardiovascular diseases.
In order to prevent people from breathing and inhaling too many harmful particles, PM2.5 sensor is needed to monitor PM2.5 in the air. PM2.5 sensor is also called dust sensor. PM2.5 sensor can be used to detect the dust concentration in the air around us, that is, the value of PM2.5.
The working principle of PM2.5 sensor is developed according to the light scattering principle. Particles and molecules will scatter light and absorb part of the energy of light. When a beam of parallel monochromatic light is incident on the particle field to be measured, it is affected by the scattering and absorption around the particle, and the light intensity is attenuated. In this way, the relative decay rate of the incident light passing through the concentration field to be measured can be obtained. The relative decay rate basically reflects the relative concentration of dust to be measured. The intensity of light is proportional to the intensity of the electrical signal converted by photoelectricity. By measuring the electric signal, the relative attenuation rate can be obtained, and then the dust concentration in the field to be measured can be determined.
PM2.5 detector is a special instrument for measuring the value of PM2.5 in the air. It is applicable to the measurement of public place environment, atmospheric environment, indoor air and vehicle air, as well as the evaluation and analysis of purification efficiency of air purifier.
Infrared dust sensor supplier luftmy——HPD05 infrared dust sensor is equipped with an infrared light-emitting diode and a highly sensitive photoelectric receiving sensor. When the infrared light-emitting diode sends out light, it will produce reflected light when encountering dust. The photoelectric sensor reflects the concentration of dust in the air by detecting the intensity of the reflected light. The sensor directly outputs PWM signal, and the PWM width is the current concentration value. HPD05 has the advantages of stable detection ability, high production efficiency and double advantages. The infrared dust sensor HPD05 has the characteristics of small volume, high precision, low power consumption, short response time and stable operation under high dust concentration. The infrared dust sensor can be used in air quality monitor, dust particle detector, etc.