High-sensitivity multi-reflection optical absorbing device

Abstract

The invention discloses a high-sensitivity multi-reflection optical absorbing device which comprises a reflection optical cavity, end covers, an intermediate infrared LED (Light Emitting Diode) light source and two photodiodes, wherein the end covers are connected to the upper end and the lower end of the reflection optical cavity in a sealing manner, an air inlet and an air outlet are respectively formed in the upper end cover and the lower end cover; the reflection optical cavity is a stainless steel cylindrical member, the inner wall of the reflection optical cavity is a diffuse reflection surface formed by gold plating after coarse grinding, the reflection optical cavity is provided with an optical inlet and two optical outlets along the axial direction of the side wall, the intermediate infrared LED light source is arranged in the optical inlet, and the photodiodes are arranged in the optical outlets. The high-sensitivity multi-reflection optical absorbing device is capable of effectively prolonging the length of a detection optical distance within a smaller space, has the characteristics of compact structure, convenience in regulation, stable light path, small influence by environment temperature, high sensitivity and detection precision, and the like, and is especially suitable for measuring concentration of hydrocarbon explosion gases in a ship cabin environment.

Description

technical field [0001] The invention relates to the fields of gas detection and analysis technology and optical technology, in particular to a multiple reflection optical absorption device. Background technique [0002] In gas detection and analysis technology and optical technology, near-infrared and mid-infrared absorption spectroscopy are generally used to measure gas components in the air. According to Beer-Lambert's law, light of a specific wavelength will be absorbed when propagating in a gas. There is a definite exponential relationship between the gas absorbance and the product of the gas absorption path length and the gas concentration. Based on this principle, the absorbance of the gas can be obtained by measuring the absorbance. concentration. When using this method to measure a gas with a lower concentration, in order to improve the detection sensitivity, it is necessary to increase the length of the absorption path of the gas. Chinese Patent Publication No. CN...

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Problems solved by technology

The technical solution announced in the application for invention achieves the purpose of effectively increasing the detection optical path length in a small space, and can be used to measure trace gases in the atmosphere, but the technical solution disclosed in the application for invention has the following defects: First, it needs Installing a main reflector and two secondary reflectors to achieve multiple reflections has a complex structure, large structure size, and high manufacturing costs; second, the device is susceptible to temperature drift due to the influence of external ambient temperature, which affects sensitivity and detection accuracy

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