Optical system for detecting size and shape of micro-particles

Abstract

The invention discloses an optical system for detecting the size and the shape of micro-particles. A laser beam is homogenized through an optical fiber to form a parallel light beam having good uniformity, then the parallel light beam shoots into a spherical cavity mirror along the main axis direction of a spherical cavity mirror system through a reasonable optical path layout, the incident light beam converges into an object point of the spherical cavity mirror with a sample gas flow, the sample gas flow is guided into 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 of particle size measurement. Scattering light except the forward scattering light shoots to an image point of the spherical cavity mirror in a large space angle range, a surface shaped CCD is placed on an objective lens image plane behind the image point, and the surface shaped CCD is mainly used for detecting particle shape information. The optical system has clever layout, reasonable structure and good working effect.

Description

Technical field [0001] The invention relates to an optical sensor. Background technique [0002] Small particle detection technology plays a vital role in scientific research, industrial sites, and atmospheric environment monitoring. The detection technology mainly includes optical method, electrical method, and dynamic method. Among them, optical method is widely used because of its wide measurement range, no contact with the sample, fast, automatic and real-time, and typical instruments such as Coulter, Climet and ROYCO particle counter, domestic laser particle counter, etc. But these instruments can only be used to measure the size of tiny particles, and the shape detection is rarely involved; not only that, 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 symmetric ellipsoidal mirror is designed to measure th...

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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