Chinese Journal of Lasers, Volume. 47, Issue 1, 0111002(2020)

Carbon Monoxide Detection Based on Photoacoustic Spectroscopy

Xin Liu, Ting Zhang, Gang Zhang, Guangzhen Gao, and Tingdong Cai*
Author Affiliations
  • Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering,Jiangsu Normal University, Xuzhou, Jiangsu 221116, China
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    A carbon monoxide (CO) measurement system based on photoacoustic spectroscopy with a 2.3 μm mid-infrared tunable diode laser is built. The CO absorption line at 4300.699 cm -1 is selected as the sensing object. In order to eliminate the influence of long relaxation time of CO molecule on measurement, water vapor is added into experimental gas to enhance CO photoacoustic signal. By optimizing the modulation parameters, the optimal modulation amplitude and modulation frequency of the system are determined to be 4.29 cm -1 and 785 Hz,respectively. Under the optimal experimental conditions, there is a good linear relationship between the second harmonic signal of the selected spectral line and the CO concentration, and the linearity is 0.994. The 2.13×10 -6 volume fraction of CO in the air can be retrieved from the relationship. Finally, by using the Allan variance to analyze the long-term stability of the system under dry and wet conditions, the detection limits under dry and wet conditions are 1.18×10 -7 and 0.58×10 -7, respectively. It is proved that the addition of water vapor can effectively improve the CO detection sensitivity of the system.

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    Xin Liu, Ting Zhang, Gang Zhang, Guangzhen Gao, Tingdong Cai. Carbon Monoxide Detection Based on Photoacoustic Spectroscopy[J]. Chinese Journal of Lasers, 2020, 47(1): 0111002

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    Paper Information

    Category: spectroscopy

    Received: Jul. 22, 2019

    Accepted: Sep. 26, 2019

    Published Online: Jan. 9, 2020

    The Author Email: Tingdong Cai (caitingdong@126.com)

    DOI:10.3788/CJL202047.0111002

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