Results 91 to 100 of about 3,337,551 (141)
Journal of Spectroscopy, 2015 Acoustic microresonators were added to the recently developed multi-QTF based QEPAS spectrophone to enhance the signal amplitude. Two kinds of “on-beam” configurations were experimentally investigated in detail.
Huadan Zheng +8 more
doaj +1 more source
Acoustic Detection Module Design of a Quartz-Enhanced Photoacoustic Sensor
Sensors, 2019 This review aims to discuss the latest advancements of an acoustic detection module (ADM) based on quartz-enhanced photoacoustic spectroscopy (QEPAS). Starting from guidelines for the design of an ADM, the ADM design philosophy is described.
Tingting Wei +3 more
doaj +1 more source
Multi-pass quartz-enhanced photoacoustic spectroscopy-based trace gas sensing
, 2021 A multi-pass quartz-enhanced photoacoustic spectroscopy (MP-QEPAS)-based trace gas sensor is reported. In MP-QEPAS, a multi-pass laser beam pattern through the prong spacing of a quartz tuning fork (QTF) is obtained by means of two right-angle prisms.
Sampaolo, Angelo +8 more
core +1 more source
New approaches in quartz-enhanced photoacoustic sensing
, 2015 We report on the design and realization of custom quartz tuning forks with different geometries and sizes aimed to improve the photoacoustic effect in quartz-enhanced photoacoustic (QEPAS) sensor systems.
Sampaolo, Angelo +4 more
core +2 more sources
Quartz tuning fork embedded off-beam quartz-enhanced photoacoustic spectroscopy
Optics Letters, 2019 In order to achieve a high acoustic coupling strength and detection sensitivity and to simplify the assembly and alignment process in quartz-enhanced photoacoustic spectroscopy (QEPAS) technique, a novel quartz tuning fork (QTF) embedded off-beam QEPAS (E-OB-QEPAS) spectrophone was proposed.
Lien Hu +4 more
openaire +2 more sources
Purely wavelength- and amplitude-modulated quartz-enhanced photoacoustic spectroscopy
Optics Express, 2016 We report here on a quartz-enhanced photoacoustic (QEPAS) sensor employing a quantum cascade laser (QCL) structure capable of operating in a pure amplitude or wavelength modulation configuration. The QCL structure is composed of three electrically independent sections: Gain, Phase (PS) and Master Oscillator (MO).
Patimisco, Pietro +9 more
openaire +4 more sources
Planar Laser-Based QEPAS Trace Gas Sensor
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 +1 more source
, 2022 Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) has become a gas sensing leading-edge technology thanks to multi-species detection, modularity, ruggedness, portability, and real time operation.
Sampaolo A. +7 more
core
Photothermal detection of trace compounds in water, using the deflection of a water meniscus [PDF]
, 1998 A novel photothermal detector is described, based on a closed cell suitable for use with low-frequency modulated continuous-wave light sources. Photothermal expansion in aqueous samples caused the deflection of a water meniscus held across a 200μℳ radius
Johnson, Mark +2 more
core +1 more source
Breath analysis by quartz enhanced photoacoustic spectroscopy: A clinical study
International audienceA new silicon based capacitive sensor is developed for photoacoustic gas detection. It is precisely designed to overcome damping losses and enhance signal-to-noise ratio.
Seoudi, T +8 more
core +1 more source