Research On Optimization Of Laser Particle Size Measurement Based On The Combined Spectrum Technology

Particles have great influence in many fields, such as Environment, Metallurgy,Construction Materials, medical treatment, chemical industry, the hydrology waterconservation, aerospace industry and so on. The Laser Particle Size Analyzer is one of themost commonly-used tools to measure the particle size distribution.Based on the combination of spectral technique, this paper produces a new prototype oflaser particle size analyzer to optimize the mechanical structure and expand themeasurement range. Some experiments are made with satisfactory results.The main contents of my thesis are as follows.Firstly, according to the optical lens parameters of the original integral prototype, thesilicon photoelectric detectors are redesigned. The radius of the detecting rings increase inturn from the inside out. The radius of the inner rings of the main detecting ring is inarithmetic progression and the outer ring is in geometric progression. The pretreatmentprocess is needed in the process of machining to avoid uneven coating to make theinstrument processing feasibly.Secondly, to transmit the weak signals from the99detecting rings, two PCB boards aredesigned. One is used to amplify the signal and the other one is data acquisition circuitbased on USB, which make the new prototype smaller and more integrative.Finally, a new prototype is designed and the whole software system was improved forexperiment. With the new prototype, a series of desired results was obtained.