High-sensitivity methane detection based on QEPAS and H-QEPAS technologies combined with a self-designed 8.7 kHz quartz tuning fork [PDF]
Photoacoustics, 2023 Methane (CH4) is a greenhouse gas as well as being flammable and explosive. In this manuscript, quartz-enhanced photoacoustic spectroscopy (QEPAS) and heterodyne QEPAS (H-QEPAS) exploring a self-designed quartz tuning fork (QTF) with resonance frequency (
Tiantian Liang +4 more
doaj +6 more sources
Quartz-enhanced photoacoustic spectroscopy (QEPAS) and Beat Frequency-QEPAS techniques for air pollutants detection: A comparison in terms of sensitivity and acquisition time [PDF]
Photoacoustics, 2023 In this work, a comparison between Quartz Enhanced Photoacoustic Spectroscopy (QEPAS) and Beat Frequency-QEPAS (BF-QEPAS) techniques for environmental monitoring of pollutants is reported.
Biao Li +9 more
doaj +6 more sources
Planar Laser-Based QEPAS Trace Gas Sensor [PDF]
Sensors, 2016 A novel quartz enhanced photoacoustic spectroscopy (QEPAS) trace gas detection scheme is reported in this paper. A cylindrical lens was employed for near-infrared laser focusing.
Yufei Ma +7 more
doaj +6 more sources
Development of Compact Electronics for QEPAS Sensors [PDF]
SensorsRemarkable advances in Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) made it one of the most effective gas-sensing techniques in terms of sensitivity and selectivity. Consequently, its range of possible applications is continuously expanding, but in
Vincenzina Zecchino +5 more
doaj +4 more sources
Towards low-cost QEPAS sensors for nitrogen dioxide detection
Photoacoustics, 2020 Increasing awareness of the adverse health effects of air pollution leads to a demand of low-cost sensors for the measurement of pollutants such as NO2.
P. Breitegger +5 more
doaj +5 more sources
Optomechanical energy enhanced BF-QEPAS for fast and sensitive gas sensing [PDF]
PhotoacousticsTraditional beat frequency quartz-enhanced photoacoustic spectroscopy (BF-QEPAS) are limited by short energy accumulation times and the necessity of a decay period, leading to weaker signals and longer measurement cycles.
Weilin Ye +5 more
doaj +5 more sources
Spatially engineered optical–acoustic matching in quartz-enhanced photoacoustic spectroscopy [PDF]
PhotoacousticsQuartz-enhanced photoacoustic spectroscopy (QEPAS) offers high sensitivity for trace-gas detection, but its performance is often limited by a spatial mismatch between distributed photoacoustic excitation and the intrinsic sensitivity region of the quartz
Ruyue Cui +10 more
doaj +2 more sources
Sensitivity improvement of quartz-enhanced photoacoustic spectroscopy using the stochastic resonance method [PDF]
PhotoacousticsQuartz-enhanced photoacoustic spectroscopy (QEPAS) is a promising technique for trace gas sensing, offering advantages such as compact size and high sensitivity. However, noise remains a critical factor limiting detection sensitivity.
Yingchao Xie +10 more
doaj +2 more sources
Assessment of vibrational-translational relaxation dynamics of methane isotopologues in a wet-nitrogen matrix through QEPAS [PDF]
Photoacoustics, 2023 Here we report on a study of the non-radiative relaxation dynamic of 12CH4 and 13CH4 in wet nitrogen-based matrixes by using the quartz-enhanced photoacoustic spectroscopy (QEPAS) technique.
Mariagrazia Olivieri +9 more
doaj +2 more sources
Optical synchronous signal demodulation-based quartz-enhanced photoacoustic spectroscopy for remote, multi-point methane detection in complex environments [PDF]
PhotoacousticsWe present a novel optical synchronized signal demodulation (OSSD) method applied in quartz-enhanced photoacoustic spectroscopy (QEPAS) for remote gas sensing. Using 1 % of the laser source as an optical synchronization signal, kilometer-scale remote gas
Bo Sun +9 more
doaj +2 more sources