Spectroscopic Detection Of Methane At A Ppt Sensitivity Level In Mid-ir With A Long-path Multipass Cell

Schuessler, Hans A

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https://hdl.handle.net/2142/111469 Copy

Description

Title

Spectroscopic Detection Of Methane At A Ppt Sensitivity Level In Mid-ir With A Long-path Multipass Cell

Author(s)

Schuessler, Hans A

Contributor(s)

• Kolomenskii, Alexandre
• Bounds, James R
• Rodriguez, Carlos
• Xia, Jinbao

Issue Date

2021-06-24

Keyword(s)

Spectroscopy as an analytical tool

Abstract

Highly sensitive detection of methane is important for biomedical applications, environmental monitoring, and the detection of leaks in the gas and oil industry. An ultra-high sensitivity sensor employing a mid-IR (MIR) interband cascade laser (center wavelength of 3.37 micron) and a multi-pass cell (MPC) was developed for methane detection. The ultra-high sensitivity is achieved due to the high absorbance in the MIR, a long interaction path length, and the implementation of a wavelet denoising processing algorithm. The long interaction path of 580 m was achieved with a confocal MCP and the distance between the mirrors of 1 m. The performance of the sensor was tested in two measuring modes: direct absorption spectroscopy (DAS) and wavelength modulation spectroscopy (WMS). For the sensor working in the DAS measurement mode the optimal set of sub-wavelet functions was determined and utilized for denoising and the minimum of the Allan deviation of the sensor of 3 ppb was achieved with an averaging time of 200 s. For the WMS measuring mode the sensor detection limit for methane of 560 ppt with 290 s averaging time was determined from the Allan deviation analysis. The developed sensor is suitable for a compact and portable design and has broad applicability in the high-sensitivity measurements of methane and other trace gases. This work was supported by the Robert A Welch Foundation, grant No A1546 and the T3 grant from Texas A and M University and Open Fund of State Key Laboratory of Applied Optics (SKLA02020001A12). [1] Jinbao Xia et al. A sensitive methane sensor of a ppt detection level using a mid-infrared interband cascade laser and a long-path multipass cell, Sensors and Actuators B: Chemical, 334, 129641 (2021). [2] Jinbao Xia: State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences Changchun, 130033, China

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111469

DOI

10.15278/isms.2021.RF10

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