An Optical System for Detecting the Size and Shape of Particles Using a Rotationally Symmetric Elliptical Cavity Mirror

Abstract

The invention discloses an optical system for detecting a microparticle size and a microparticle shape by a rotationally symmetrical ellipsoidal cavity mirror. A laser beam is homogenized through an optical fiber to form a parallel light beam having good uniformity, then the parallel light beam shoots along the main axis direction of a spherical cavity mirror system into the rotationally symmetrical ellipsoidal cavity mirror through a reasonable optical path layout, and the incident beam converges into a focus of the rotationally symmetrical ellipsoidal cavity mirror with a sample gas flow; the sample gas flow is introduced along the direction perpendicular to the main axis direction of the system, and a particle forward scattering light signal is accepted by a photomultiplier tube and is used as a main signal for particle size measurement. Scattering light except the forward scattering light shoots to another focus of the rotationally symmetrical ellipsoidal cavity mirror in a large angle scope, and a surface shaped CCD is placed on an objective lens image plane behind the focus and is mainly used for detecting particle shape information. The optical system has the advantages of clever layout, reasonable structure, and good working effect.

Description

technical field [0001] The invention relates to an optical sensor. Background technique [0002] Particle detection technology plays a vital role in scientific research, industrial sites, and atmospheric environment monitoring. Its detection technologies mainly include optical method, electrical method, and kinetic method. Among them, optical method is the most widely used for its wide measurement range, no contact with samples, fast, automatic and real-time. Typical instruments such as Coulter, Climet and ROYCO particle counter, domestic laser particle counter, etc. However, these instruments can only be used to measure the size of the particles, and the detection of the shape is rarely involved; not only that, but these instruments also have the defects of limited acceptance angle range and poor light uniformity in the photosensitive area. For this reason, in the patent [CN201110346535.0], an optical sensor with a rotationally symmetrical elliptical cavity mirror is desi...

AI Technical Summary

Problems solved by technology

However, these instruments can only be used to measure the size of particles, and the detection of the shape is rarely involved; not only that, but these instruments also have the defects of limited acceptance angle range and poor light uniformity in the photosensitive area

For this reason, in the patent [CN201110346535.0], an optical sensor with a rotationally symmetrical elliptical cavity mirror is designed to measure the size and shape of particles. The uniformity of light has also been improved to some extent, but because the large-angle scattered light receiver only uses three photocells located at the vertices of the triangle, the amount of information collected is too small, which affects the detection accuracy of the shape, and also has a certain degree of difficulty in the detection of the size of the particles. Influence; In addition, the optical path layout adopted in this design to improve the beam uniformity is complex and easily affected by transportation, etc.

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