Optical system that detects the size and shape of fine particles with improved measurement accuracy

Abstract

The invention discloses a measurement precision improved optical system for detecting the size and shape of a microparticle. A laser beam is subjected to optical fiber homogenization treatment to form a parallel beam with favorable homogeneity and is irradiated into a spherical-cavity mirror along the principal axis direction of a spherical-cavity mirror system by virtue of a reasonable optical path layout, the parallel beam and sample air flow are converged at an object point of the spherical-cavity mirror, the sample air flow is introduced along the direction vertical to the principal axis direction of the system, and an optical signal forwards scattered by a particle is accepted by a photomultiplier tube so as to be used as a main signal for measuring the size of the particle. Scattered light except for forward scattered light is irradiated on an image point of the spherical-cavity mirror within a large spatial angle range, and a surface shape CCD (Charge Coupled Device) is arranged on an object mirror image plane behind the image point and is mainly used for detecting the shape information of particle size. The measurement precision improved optical system is artful in layout, reasonable in structure and good in working effect.

Description

[0001] The present invention is a divisional application with application number: 201310306923.5, title: "Optical system for detecting the size and shape of tiny particles", and filing date: 2013.7.22. technical field [0002] The invention relates to an optical sensor. Background technique [0003] Microparticle 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 tiny particles, and the detection of the shape is rarely involved; not only that, but these instruments also have the defects of limited a...

AI Technical Summary

Problems solved by technology

However, these instruments can only be used to measure the size of tiny 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, especially the shape detection accuracy; in addition, in this design The optical path layout adopted to improve the uniformity of the beam has a complex structure and is easily affected by transportation, etc.

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