Results 201 to 210 of about 2,335 (228)
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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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Calibration-free near-infrared methane sensor system based on BF-QEPAS
Infrared Physics & Technology, 2023W. Ye +6 more
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A compact integrated dual-spectroscopy gas detection structure based on QEPAS and QEPTS using a QTF
Infrared Physics & Technology, 2023Jing Zhao +4 more
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