Improvement Of Small-angle Light Scattering Method Particle Testing Theory And Technology Research,

The technique of particle size has developed into a special subject because of the wide application in recent decades. As its lots of virtues, laser particle size, which based on light scattering, has caught much attention in all these techniques. It has been made a great progress with the development of computer, electronics and mechanism, especially in these years.Now, the most application in laser particle size is forward direction light scattering of small angle. It has the virtues of the simpleness measuring theory, the fast measuring speed, the measure of non-touch x on-line as well as automatization, and no need to know the physical character of measured particle, the few limits, and the wide apply. But along with the measuring require of small particle and higher precision, it emerges some shortage. How to improve the light scattering measure's precision and extend the measure's lower limit based on the Fraunhofer diffraction and Mie scattering theory is the purpose of this paper.In this paper, virtual instrument software Lab VIEW and mathematic analysis software Matlab, HIQ are used as software platform. The forward direction light scattering of small angle and side-direction scattering experiment system is also set up. Based on this system, many experiments are carried on.At first, according as the particle measuring development situation, the paper introduces all kinds of testing technique of particle.Then the Fraunhofer diffraction and Mie scattering theory are introduced in this paper, and the corresponding arithmetic is also analyzed. For the shortage of forward direction light scattering of small angle, the study task is brought forwardFrom the theory, arithmetic and experiment system and so on, this paper discusses the methods of improving forward direction light scattering of small angle, including:1)For the alterable measure range and lower measure lower limit, the counter-Fraunhofer transform is adopted2)Mie scattering modify is applied in the paper, and instead of integral, unique cumulation sum method is used in the calculate of matrix T.3)The new arithmetic-auto adapt subsection approach of both direction is put forward. It has the auto adapt and higher precision, and has applied at the laser particle sizing equipment in our lab.4)Increase multi-input optical fiber sensor at side-direction, and extendthe equipment's measuring scope.At last, the whole experiment system is introduced entirely, including hardware and software. The experiments prove that the methods in this paper are feasible.