The Underlying Hardware And Software System Of Liquid Particle Counter Based On Light Blocking And Its Calibration

Intravenous infusion and injection plays an important role in medical. The insolubleparticles in liquid will enter the human body inevitably by intravenous infusion orintravenous injection. It will threat the human health, even threat the human life."Theinspection method of insoluble particles in injection" in the2010edition of ChinesePharmacopoeia continue to use light-blocking as one of the two methods for detectinginsoluble particles. It means that the liquid particle counter based on light blocking hasvery practical significance.Light-blocking means let the laser through the detection area of the sensor. When theparticles in the liquid through the narrow detection zone, then the light whichperpendicular to liquid flow incidently weakened because of blocking by the particles.Therefore, the output of the sensor reduced.The size of the particle can be known becauseof the variation of the signal is proportional to the cross-sectional area of the particle.This article is a summary of the research in SuJing Group. The research work andthesis's structure is divided into four parts. The first part discusses the design about sensorbased on the light blocking, and mainly discusses the amplifier circuit. The second part ofthe instrument is hardware design of the control system. This part use a controller namedP89V51RD2and CPLD to achieve the functions like sampling, comparing, counting,motor driving and communicating with PC; The third part discusses about the controlprogram. The fourth part is the calibration of the instrument by large number ofexperiments.