Double-optical-path multi-gas infrared sensor

Abstract

The invention relates to a double-optical-path multi-gas infrared sensor which mainly comprises a double-optical-path multi-gas detection cavity, an infrared light source 10, a multi-element detector 2, a waterproof and breathable membrane 3, a signal amplification module 15, an analog-digital conversion module 16, a signal processing module 17 and a communication display module 18, wherein the double-optical-path multi-gas detection cavity comprises a ring-shaped cavity 14 and a cover plate 4; the lower half part of infrared light emitted by the infrared light source 10 is reflected by a planar reflective mirror 8 and then reaches the lower half part of the multi-element detector 2, so that a first short optical path is formed; the upper half part of the infrared light emitted by the infrared light source 10 is reflected by the inner surface of the ring-shaped cavity 14 for a plurality of times and then reaches the upper half part of the multi-element detector 2, so that a second long optical path is formed; therefore, the long optical path and the short optical path can be realized in the single cavity. After the double-optical-path multi-gas infrared sensor is used, the gases with different infrared absorption rates can be detected at the same time, and the demand of different detection precisions of the same gas can be met; the double-optical-path multi-gas infrared sensor is capable of conveniently realizing detection and identification of multiple gases, thus being widely applied to real-time monitoring of the gases on multiple occasions.

Description

technical field [0001] The invention relates to an infrared gas sensor, more precisely, the invention relates to a double optical path multi-gas infrared gas sensor. The invention belongs to the field of infrared gas sensors. Background technique [0002] In recent years, with the development of the economy, the implementation of the government's low-carbon environmental protection policies, and the improvement of people's safety awareness, the market demand for gas sensors has increased year by year. Infrared sensors are characterized by high precision, good selectivity, long life, no poisoning, and no dependence on It has been extensively studied due to its advantages such as being free from oxygen and being less disturbed by the environment. [0003] CN 2507011Y discloses an array type gas sensor composed of light cone array, light cone sleeve, optical filter array, etc., which can measure multiple gas components at the same time. CN200947084Y discloses an electrically ...

AI Technical Summary

Problems solved by technology

CN 102721662A discloses a method of extending the optical path without relying on reflection, which eliminates the problem that the sensor fails quickly after the reflective surface is polluted

[0004] The above published information shows that although they are exquisitely designed and have an exquisite optical path inside the cavity, their optical path is unique.

Since different gases have different absorption strengths of infrared rays, multiple gases are detected under a single optical path at the same time, and the gas with strong infrared absorption is taken into account in the optical path design, which will inevitably affect the detection accuracy of gases with weak infrared absorption , and vice versa; at the same time, the main infrared absorption peaks of some gases are relatively close, and there are overlapping areas, so it is difficult to distinguish what kind of gas it is during detection. The strength of the secondary absorption peaks is different, and it is bound to lose sight of the other under a single optical path

Therefore, a single optical path is not conducive to the simultaneous detection of gases with different infrared absorption rates and the accuracy of gas screening

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