Results 141 to 150 of about 909 (177)

QEPAS sensor in a butterfly package and its application

Applied Optics, 2021
Molecular gases are highly relevant in healthcare, production control, safety, and environmental monitoring. They often appear in small concentrations. The measurement of trace gases has increasingly become a key technique in those domains. Quartz-enhanced photoacoustic spectroscopy (QEPAS) is a suitable method that can provide the required low ...
Tobias Milde, Morten Hoppe, Herve Tatenguem, Hanna Rohling, Sebastian Schmidtmann, Martin Honsberg, Wolfgang Schade, Joachim Sacher   +7 more
openaire   +2 more sources

A QEPAS Sensor in a Butterfly Package

Optical Sensors and Sensing Congress, 2020
Quartz-Enhanced-Photo-Acoustic-Spectroscopy (QEPAS) is a modern, promising trace gas measuring technique. One main advantage of QEPAS over other trace-gas spectroscopes is its size. The miniaturization of the sensor-system is the next big challenge in the development.
Tobias Milde, Morten Hoppe, Hervé Tatenguem, Hanna Rohling, Sebastian Schmidtmann, Martin Honsberg, Wolfgang Schade, Joachim Sacher   +7 more
openaire   +1 more source

Broadband QEPAS with IR-LEDs

Conference on Lasers and Electro-Optics 2012, 2012
An IR-LED at 3.4 μm and an off-beam QEPAS cell as detector are utilized for absorption spectroscopy. For 10 cm absorption path a detection limit of 382 ppm is achieved for methane.
Stefan Böttger, Ulrike Willer, Wolfgang Schade   +2 more
openaire   +1 more source

QEPAS sensor for breath analysis: a behavior of pressure

Applied Optics, 2018
The measurement of trace gases has increasingly become a key technique in healthcare and other medical applications. Quartz-enhanced photoacoustic spectroscopy (QEPAS) is a suitable method that can provide the required characteristics in such applications for a comparatively low cost and small size.
Tobias Milde, Morten Hoppe, Herve Tatenguem, Mario Mordmüller, James O’Gorman, Ulrike Willer, Wolfgang Schade, Joachim Sacher   +7 more
openaire   +2 more sources

Miniaturized QEPAS Detector Concept for Methane

Conference on Lasers and Electro-Optics, 2020
QEPAS enables very compact detectors due to the small detection volume. Currently limitations originate from bulky control electronics, like lock-in amplifiers. We report on reducing size and energy of FPGA based devices and their application in methane detection.
Hervé Tatenguem, Amrita D. Josnan, Tobias Milde, Morten Hoppe, Joachim Sacher   +4 more
openaire   +1 more source

A Novel QEPAS with Microresonator in the Open Environment

International Journal of Thermophysics, 2012
An 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, Yong Zhu, Wei Wei, Ning Wang, Weiyi Bao   +4 more
openaire   +1 more source

Modeling and Design of a Semi-Integrated QEPAS Sensor

Journal of Lightwave Technology, 2021
Quartz enhanced photo acoustic spectroscopy (QEPAS) has gained a growing interest in recent years for gas sensing technology because of the high sensitivity provided by sharp resonant tuning forks (QTFs) exploited as piezoelectric sound wave detectors; and the modularity, compactness, and robustness of the sensors.
Martino De Carlo, Giansergio Menduni, Angelo Sampaolo, Francesco De Leonardis, Vincenzo Spagnolo, Vittorio M. N. Passaro   +5 more
openaire   +1 more source

Acetylene-enhanced methane-QEPAS sensing

Optics Letters
Methane (CH 4 ), as a critical greenhouse gas and explosive hazard, demands highly sensitive detection for environmental monitoring and industrial safety. To address the limitation of its slow relaxation in quartz-enhanced photoacoustic spectroscopy (QEPAS), this paper reported a novel ...
Jin Sun, Ying He, Shunda Qiao, Chu Zhang, Yufei Ma   +4 more
openaire   +2 more sources

QEPAS spectrophones: design, optimization, and performance

Applied Physics B, 2010
The impact of design parameters of a spectrophone for quartz-enhanced photoacoustic spectroscopy on its performance was investigated. The microresonator of spectrophone is optimized based on an experimental study. The results show that a 4.4 mm-long tube with 0.6 mm inner diameter yields the highest signal-to-noise ratio, which is ∼30 times higher than
L. Dong, A. A. Kosterev, D. Thomazy, F. K. Tittel   +3 more
openaire   +1 more source

QEPAS detector for rapid spectral measurements

Applied Physics B, 2010
A quartz enhanced photoacoustic spectroscopy sensor designed for fast response was used in combina- tion with a pulsed external cavity quantum cascade laser to rapidly acquire gas absorption data over the 1196- 1281 cm −1 spectral range. The system was used to measure concentrations of water vapor, pentafluoroethane (freon- 125), acetone, and ethanol ...
A. A. Kosterev, P. R. Buerki, L. Dong, M. Reed, T. Day, F. K. Tittel   +5 more
openaire   +1 more source