Method for measuring particle grain diameter

Abstract

The invention relates to a method for measuring grain diameter by utilizing binocular vision matching and particle picture gray scale difference, pertaining to the technical field of optical grain diameter measurement. According to the characteristic that different forward angle scattered lights have light intensity differences and by utilizing a digital particle image velocimetry (DPIV) imaging system provided with dual-cameras, the method obtains two particle pictures with gray scale difference, the flow fields of which are formed by single exposure; after the particle pictures are pre-treated by an image processing technique, the mating of a same particle corresponding to two particle image points on the two particle pictures is realized according to a binocular vision matching principle; the grain diameter of the particle is obtained by substituting the gray scale value summation of the two particle image points into a grain diameter solving formula, thus obtaining the particle size information of the whole flow field; the method has the reduced requirement to the light intensity and the stability of laser and the particle mating method is simple and convenient, thus reducing the influence of system errors, the digital graphic processing technique and laser diffraction on the measurement result of the particle size, overcoming the deficiencies and defects in the prior art and having substantial characteristics and prominent advancement.

Description

technical field [0001] The invention belongs to the technical field of particle size optical measurement, and relates to a method for measuring particle size in a flow field, in particular to a particle image velocity field (PIV) imaging system equipped with dual cameras to capture flow field particle images, and uses dual A method for measuring particle size by eye-visual matching and gray-scale difference of particle images. Background technique [0002] Particle Image Velocimetry is a brand-new flow field display measurement technology developed in the past two decades. It integrates computer image processing and optical technology, and can measure the transient velocity of the entire flow field in the research space. And the advantages of little interference to the flow field, become a very effective tool for flow field testing and analysis. [0003] The experimental measurement of particle size and velocity distribution is the main content of flow field display and qua...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that various digital image analysis preprocessing methods will affect the size of the particle image point, thereby affecting the determination of the true size of the particle diameter; at the same time, this method requires high stability of the laser intensity. Once the laser intensity changes , it is necessary to reset various digital image analysis and processing methods; the fluctuation of the laser energy of the two exposures is likely to cause errors in the comparison results; in addition, particle imaging is also affected by laser diffraction and PIV system errors

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