Design And Research Of Embedded Dust Particle Counting System Based On Mie Scattering

Due to the outbreak of the new crown epidemic in recent years,masks have become a necessity in daily life.Medical surgical masks have a filtration efficiency of more than 30% for non-oily particles with a diameter of0.3 μm,and the commonly used inspection method in mask production is to use particle counters to detect particles in the air passing through the mask.At the same time,particle counters are often used for air cleanliness testing in high-standard production environments.Compared with foreign particle counters,the instruments currently developed in China have the disadvantages of difficult development,unfriendly human-computer interaction and bulky size.Combining the above pain points and actual project needs,this topic has conducted a comprehensive investigation on the theory,instruments and related technologies involved in dust particle counting.And finally finished the Mie Design and Research of Scattered Embedde d Dust Particle Counting System combined with the relevant knowledge of light scatte ring theory,circuit design and embedded development.The main research contents are as followsBy analyzing the principle of light scattering dust particle counting,this subject divides the system into three parts.Firstly,for the laser particle sensor part,this topic analyzes its structure and principle,carried out the related structure design and particle calibration;secondly,this project takes the miniaturization of the system as the design goal,realizes the weak electric signal amplification and filtering,six-channel signal pulse classification,STM32 minimum system and multiple IO expansion interfaces on the PCB board with a size of 10cm×6cm.And then,developed a communication protocol,realized WIFI communication,pulse counting,timing,stora ge,multiple timing sampling and UCL discrimination,and designs the corresponding host computer software,which has good human-computer interaction feedbackFinally,this article also conducts an overall debugging and testing comparison,including the functional for upper computer and the data comparison with domestic instruments.Compared with the domestic equipment,the average particle number obtained by the system is below 2.5% except for the particle size of 10 μm.The obtained cleanliness level is consistent,which can meet the basic cleanliness measurement requirements.