Results 151 to 160 of about 1,073 (164)
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Numerical modeling and performance optimization of QEPAS spectrophone
SPIE Proceedings, 2012The spectrophone performance for QEPAS is numerically investigated by using a finite element method. The effect of varying system parameters such as the excitation frequency, relative position between the acoustic resonant tubes and the quartz tuning fork, and the dimensions of resonant tubes are examined A pair of rigid tubes, each with a length of ...
Yingchun Cao, Wei Jin, Hoi Lut Ho
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NIR diode laser-based QEPAS for acetylene detection
SPIE Proceedings, 2012Quartz-enhanced photoacoustic spectroscopy with a near infrared distributed feedback diode laser at 1.53 μm is demonstrated for acetylene detection at atmospheric pressure and room temperature. The P(9) absorption line in the ν1+ν3 band of C2H2 is selected for light absorption and photoacoustic pressure wave excitation.
Yingchun Cao, Wei Jin, Hoi Lut Ho
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A Novel QEPAS with Microresonator in the Open Environment
International Journal of Thermophysics, 2012An improved quartz-enhanced photoacoustic spectroscopy (QEPAS) sensing system for trace gas detection is proposed. The optical fiber Fabry–Perot (F–P) demodulation method is used to replace the conventional electrical one in the QEPAS system. The experimental QEPAS system, which has a microresonator consisting of two stainless steel tubes with a length
Cheng Lin +4 more
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Pivotal techniques evaluation in QEPAS system for engineering applications
Measurement, 2019Abstract Efforts were made in this study to evaluate a series of pivotal techniques in standard quartz tuning fork (QTF) based quartz enhanced photoacoustic spectroscopy (QEPAS) systems for engineering applications. In current QEPAS systems, a scanning ramp combined with high frequency sinusoidal signal is used to drive the light source for ...
Fupeng Wang +4 more
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A QEPAS sensor with a ~1.37 μm DFB laser
Asia Communications and Photonics Conference 2013, 2013We demonstrate a QEPAS sensor using a ~1.37μm DFB laser as light source and a quartz tuning fork as a transducer to detect water vapor concentration in the air.
Ping Gong +3 more
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Trace Gas Detection based on Planar Laser QEPAS Sensor
Lasers Congress 2016 (ASSL, LSC, LAC), 2016A novel planar laser based QEPAS sensor is realized by using a cylindrical lens to shape laser beam as a planar line. It has the advantages of easier beam alignment and reduction of stability requirement.
Yufei Ma +5 more
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QEPAS for chemical analysis of multi-component gas mixtures
Applied Physics B, 2010A gas sensor based on quartz-enhanced photoacoustic spectroscopy and using near-infrared, fiber-coupled diode lasers as an excitation source was developed for chemical analysis of gas mixtures containing H2S, CO2, and CH4 at concentrations from 0 to 100%. Analysis of physical phenomena affecting the sensor operation is performed, the sensor performance
A. A. Kosterev +4 more
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[Experimental research on optimization of QEPAS based spectrophone].
Guang pu xue yu guang pu fen xi = Guang pu, 2015The present paper studied the impact of geometry dimensions, located angle and detection position of a quartz tuning fork (QTF) on the sensitivity of QEPAS system. Ten kinds of QTFs were employed to compare the sensitivity with each other, and the results show that the QTF with a wedge-shape top obtains a higher quality factor and turns to be 50% more ...
Hua-Dan, Zheng +7 more
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H2S near-IR QEPAS detection in complex gas matrices
Quantum Sensing and Nano Electronics and Photonics XIX, 2023Mariagrazia Olivieri +6 more
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