Abstract

We report an open-path chirped laser dispersion spectrometer capable of detecting the atmospheric methane concentration above the background using both specular and diffusive reflective surfaces via two distinct operation modes in a stand-off detection configuration. The system is integrated with simultaneous ranging functionality, which enables average concentration measurements for varying optical pathlengths. The system was first tested for accuracy and characterized to achieve sensitivity of ${2.9}\;{{\rm ppm}} \text{-} {\rm m/Hz}^{1/2}$ and pathlength precision of ${0.2}\;{{\rm m/Hz}^{1/2}}$ with a controlled release of methane outside the laboratory. The instrument was subsequently field-deployed in the proximity of a natural gas compressor station for fugitive methane detection. The instrument successfully detected methane plumes and narrowed down the location of the plume through multi-path measurement. The field measurements were verified by a co-located reference mobile methane sensor.

© 2021 Optical Society of America

Chirped laser dispersion spectroscopy for spectroscopic chemical sensing with simultaneous range detection

Andreas Hangauer, Yifeng Chen, and Gerard Wysocki
Opt. Lett. 46(2) 198-201 (2021)

Analysis and demonstration of atmospheric methane monitoring by mid-infrared open-path chirped laser dispersion spectroscopy

Nart S. Daghestani, Richard Brownsword, and Damien Weidmann
Opt. Express 22(S7) A1731-A1743 (2014)

Hollow-core fiber photothermal methane sensor with temperature compensation

Pengcheng Zhao, Hoi Lut Ho, Wei Jin, Shangchun Fan, Shoufei Gao, and Yingying Wang
Opt. Lett. 46(11) 2762-2765 (2021)

Chirped laser dispersion spectroscopy for laser-based hydrogen sulfide detection in open-path conditions

Michał Nikodem
Opt. Express 24(10) A878-A884 (2016)

Methane leak detection by tunable laser spectroscopy and mid-infrared imaging

Thomas Strahl, Johannes Herbst, Armin Lambrecht, Eric Maier, Jonas Steinebrunner, and Jürgen Wöllenstein
Appl. Opt. 60(15) C68-C75 (2021)