• Spectroscopy and Spectral Analysis
  • Vol. 40, Issue 8, 2345 (2020)
CHENG Gang1, CAO Ya-nan1, TIAN Xing1, CAO Yuan2, and LIU Kun2、*
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
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    DOI: 10.3964/j.issn.1000-0593(2020)08-2345-07 Cite this Article
    CHENG Gang, CAO Ya-nan, TIAN Xing, CAO Yuan, LIU Kun. Influence of Photoacoustic Cell Geometrical Shape on the Performance of Photoacoustic Spectroscopy[J]. Spectroscopy and Spectral Analysis, 2020, 40(8): 2345 Copy Citation Text show less

    Abstract

    With the rapid development of modern industry, the importance of trace gas detection technology is self-evident. At present, trace gas detection technology has been widely used in environmental protection, chemical industry, bio-ecological and medical detection and other fields. Photoacoustic spectroscopy (PAS) has become one of the most important analytical methods in spectroscopic detection due to its advantages of zero background detection, no wavelength limitation of detectors, simple optical elements, convenient system regulation and maintenance. In recent years, with the rapid development of weak signal detection and laser technology, photoacoustic spectroscopy has also attracted more attention of scholars. Relevant research results provide an important design reference for improving the detection performance of photoacoustic spectroscopy. However, the current literature report rarely involves the optimization of photoacoustic cells, such as the shape of photoacoustic cells. There is a lack of in-depth exploration on such problems as the shape structure. The photoacoustic cell is one of the most important core components in the photoacoustic spectroscopy detection system. It is the cavity for carrying the gas to be tested and the place where photoacoustic coupling occurs. Its shape greatly affects the relationship between light and sound. The coupling situation affects the signal-to-noise ratio and sensitivity of the whole system. Therefore, exploring the shape of the photoacoustic pool has important theoretical significance and engineering application value. Therefore, based on the design basis of the traditional cylindrical photoacoustic cell, this paper explores and studies the structural model of the photoacoustic cell with eight typical shapes such as circle, triangle, ellipse and so on, and simulates its sound field characteristics. 3D printing technology has produced all kinds of photoacoustic cells, and analyzed the performance indexes of 8 photoacoustic cells through experiments. The longitudinal length of the photoacoustic cell designed by the constraint is equal to the perimeter of the longitudinal section. The simulation results show that the longitudinal acoustic modes of the eight photoacoustic cells are the same. The experimental results show that the acoustic resonance frequencies of the eight photoacoustic cells are the same. The size is basically the same, and is affected by the coupling of the laser source and the acoustic mode in the cavity. Their quality factors are arranged from large to small: circular, short-axis ellipse, regular pentagon, square, large circular axis, and equilateral triangle. Small circle axis shape, long axis ellipse, their cell constants are arranged in order from large to small: circular, long axis ellipse, regular pentagon, square, large circular axis shape, small circular axis shape, regular triangle, short axis ellipse . The overall results show that for the design of the photoacoustic cell in photoacoustic spectroscopy, the shape of photoacoustic cell should be circular in priority without special requirements. The research process and results of this paper can provide a reference for the optimization design of the photoacoustic cell in photoacoustic spectroscopy.
    CHENG Gang, CAO Ya-nan, TIAN Xing, CAO Yuan, LIU Kun. Influence of Photoacoustic Cell Geometrical Shape on the Performance of Photoacoustic Spectroscopy[J]. Spectroscopy and Spectral Analysis, 2020, 40(8): 2345
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