High-flow dust particle counting sensor with novel photosensitive area structure

Abstract

The invention discloses a high-flow dust particle counting sensor with a novel photosensitive area structure. An aspherical mirror, an incident diaphragm, an emergent diaphragm and a light trap are arranged in sequence in the advancing direction of light beams emitted from a high-power semiconductor laser source; a spherical reflector, a field diaphragm and a photoelectric detector are arranged in the direction vertical to a light path; the photosensitive area and the photosensitive surface of the photoelectric detector are respectively positioned at two sides of the sphere center of the spherical reflector and satisfy the geometric object image relationship; a gas circuit system consists of a sampling nozzle and an outlet nozzle; the caliber of the sampling nozzle is smaller than that of the outlet nozzle; and the sampling nozzle and the outlet nozzle are arranged unsymmetrically with respect to the photosensitive area. The high-flow dust particle counting sensor has the advantages of simple structure, small volume, high counting efficiency and high particle diameter resolution ratio and can realize correct and efficient detection on the samples of high-flow dust particles not lower than 50L/min.

Description

technical field [0001] The invention relates to a cleanliness detection device, in particular to a high-flow, high-signal-to-noise ratio, high-resolution, miniaturized high-flow semiconductor dust particle counting sensor with a novel photosensitive region structure. Background technique [0002] Dust particle counting sensor is the main measurement system used to measure particle size distribution by light scattering counting method, and it is widely used in the cleanliness detection of electronics, materials, pharmaceuticals, laboratories and other departments. Optical sensors are at the heart of the measurement system. [0003] In the technical solution adopted by the advanced laser dust particle counting sensor, the flow rate has reached 50L / min. For example, Suzhou Hongji Clean Technology Co., Ltd. applied for a utility model patent on July 12, 2010, "A Large Flow Dust Particle Counter Photoelectric sensor" (patent number CN201780264U). It includes a cavity, and the ...

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Problems solved by technology

[0004] The problems existing in the prior art are: the gas path system uses two inlet nozzles and one gas outlet nozzle, the structure is relatively complicated, and the position of the gas path is fixed and cannot be adjusted; two spherical reflectors are used to enhance the scattered light signal of the particles and at the same time The stray light signal is also enhanced, which affects the improvement of the signal-to-noise ratio; a corresponding photoelectric receiving device is installed behind a small hole on a spherical mirror to receive the scattered signal, which is easy to miss counting, and the counting efficiency is damaged, which affects the signal-to-noise ratio improvement

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