Optoacoustic spectroscopy multi-ingredient trace gas detection instrument and method

Abstract

The invention relates to an optoacoustic spectroscopy multi-ingredient trace gas detection instrument and method, and belongs to the technical field of trace gas detection. The instrument comprises amedium infrared heat radiation light source, a light gathering mirror, a chopper, an optical filter plate group, an optoacoustic pool, a laser light source, an optical collimator, an air inlet valve,an air outlet valve, a microphone, a control and signal processing circuit and a touch screen, wherein the medium infrared heat radiation light source is longitudinally coupled to the optoacoustic pool after the light gathering; the optoacoustic signals are measured by using the intensity modulation-base wave detection technology; the laser is coupled into the optoacoustic pool from the side surface and is reflected for many times on the surface of the pool wall; the optoacoustic signals are measured by using a wave-length modulation-second harmonic detection technology; the background noise interference is greatly reduced. The advantages, suitable for multi-ingredient gas measurement and realizing high detection sensitivity, of the optoacoustic spectroscopy method of the medium infrared heat radiation light source and the laser optoacoustic spectroscopy method are sufficiently used; the technical complementation is realized; the technical scheme with good competitiveness is provided for the high-sensitivity detection of the multi-ingredient trace gas.

Description

technical field [0001] The invention belongs to the technical field of trace gas detection, and relates to a photoacoustic spectrum multi-component trace gas detection instrument and method. Background technique [0002] Photoacoustic spectroscopy multi-component trace gas detection technology has obvious advantages such as high sensitivity, fast measurement speed, long working life and small sampling volume. It plays an important role in applications such as analysis and monitoring of flammable and explosive gases in coal mines. [0003] Photoacoustic spectroscopy is a spectral calorimetry technique that directly measures the heat generated by gas due to absorption of light energy, and is a background-free absorption spectroscopy technique. According to different photoacoustic excitation light sources, photoacoustic spectroscopy is mainly divided into photoacoustic spectroscopy based on mid-infrared thermal radiation light source and laser photoacoustic spectroscopy. The ...

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Problems solved by technology

[0004] The purpose of the present invention is to propose a photoacoustic spectrum multi-component trace gas detection method and instrument, aiming to solve the problem of low detection sensitivity of individual gases and the problem of mid-infrared thermal radiation light in photoacoustic spectroscopy based on mid-infrared thermal radiation light source. The problem that it is difficult to couple with the laser to the photoacoustic cell at the same time expands a larger space for the application of photoacoustic spectroscopy multi-component trace gas detection technology in the field of trace gas detection

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