Results 81 to 90 of about 218 (120)
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Radial-cavity quartz-enhanced photoacoustic spectroscopy
Optics Letters, 2021Radial-cavity quartz-enhanced photoacoustic spectroscopy (RC-QEPAS) was proposed for trace gas analysis. A radial cavity with (0,0,1) resonance mode was coupled with the quartz tuning fork (QTF) to greatly enhance the QEPAS signal and facilitate the optical alignment.
Haohua Lv +11 more
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Helmholtz-resonator quartz-enhanced photoacoustic spectroscopy
Optics Letters, 2023In this work, Helmholtz-resonator quartz-enhanced photoacoustic spectroscopy (HR-QEPAS) was developed for trace gas sensing. A pair of Helmholtz resonators with high-order resonance frequency was designed and coupled with a quartz tuning fork (QTF).
Huijian Luo +9 more
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Differential quartz-enhanced photoacoustic spectroscopy
Applied Physics Letters, 2023In this paper, a differential quartz-enhanced photoacoustic spectroscopy (D-QEPAS) sensor is reported. The differential photoacoustic cell (PAC) was used to generate the photoacoustic effect. Two quartz tuning forks (QTFs) with a quality factor (Q) up to 10 000 were used as the acoustic wave transducers. The signal of D-QEPAS sensor was doubly enhanced
Chu Zhang +5 more
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Quartz-enhanced photoacoustic spectroscopy for multi-gas detection: A review
Multi-gas detection represents a suitable solution in many applications, such as environmental and atmospheric monitoring, chemical reaction and industrial process control, safety and security, oil&gas and biomedicine. Among optical techniques, Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) has been demonstrated to be a leading-edge technology for ...
Angelo Sampaolo +2 more
exaly +4 more sources
Improved Tuning Fork for Terahertz Quartz-Enhanced Photoacoustic Spectroscopy [PDF]
We report on a quartz-enhanced photoacoustic (QEPAS) sensor for methanol (CH3OH) detection employing a novel quartz tuning fork (QTF), specifically designed to enhance the QEPAS sensing performance in the terahertz (THz) spectral range. A discussion of the QTF properties in terms of resonance frequency, quality factor and acousto-electric transduction ...
Angelo Sampaolo +2 more
exaly +5 more sources
In-plane quartz-enhanced photoacoustic spectroscopy
Applied Physics Letters, 2020An optical gas sensing technique based on in-plane quartz-enhanced photoacoustic spectroscopy (IP-QEPAS) is reported. In IP-QEPAS, the laser beam is aligned in the plane of the quartz tuning fork (QTF) to increase the interaction area between the acoustic wavefront and the QTF.
Yufei Ma +6 more
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Off-beam quartz-enhanced photoacoustic spectroscopy
Optics Letters, 2009An off-beam (OB) detection approach is suggested and experimentally investigated and optimized for quartz-enhanced photoacoustic spectroscopy (QEPAS). This OB-QEPAS configuration, very simple in assembly, not only allows for use of larger excitation optical beams and facilitating optical alignment but also provides higher enhancement of photoacoustic ...
Kun, Liu +5 more
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Quartz-Enhanced Photoacoustic Spectroscopy-Conductance Spectroscopy for Gas Mixture Analysis
Analytical Chemistry, 2023A novel spectroscopic method, named quartz-enhanced photoacoustic spectroscopy-conductance spectroscopy (QEPAS-CS), was first developed for gas mixture analysis. In QEPAS-CS, the advantage of photoacoustic detection and conductance analysis was realized by a quartz tuning fork (QTF).
Ruobin Zhuang +11 more
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Quartz-enhanced photoacoustic spectroscopy of methane isotopologues
Photonic Instrumentation Engineering VIII, 2021We report on the detection of the isotopologues 12CH4 and 13CH4 by employing a quartz-enhanced photoacoustic spectroscopy (QEPAS)-based sensor. By properly selecting the exciting light source and the working conditions, two absorption lines, having a negligible cross-section ratio temperature coefficient of -6.7‰/°C and a cross section ratio of ~ 0.06 ...
Marilena Giglio +10 more
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Non-contact quartz-enhanced photoacoustic spectroscopy
Applied Physics Letters, 2023Non-contact quartz-enhanced photoacoustic spectroscopy (NC-QEPAS) was proposed and developed for trace gas analysis. The NC-QEPAS aims at solving the problem that the quartz tuning fork (QTF) must be immersed in the gases for photoacoustic wave transducing, which limits its application for corrosive and dusty gas sensing.
Haoyang Lin +8 more
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