Results 11 to 20 of about 909 (177)
Development of Compact Electronics for QEPAS Sensors [PDF]
SensorsRemarkable advances in Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) made it one of the most effective gas-sensing techniques in terms of sensitivity and selectivity. Consequently, its range of possible applications is continuously expanding, but in
Vincenzina Zecchino +5 more
exaly +8 more sources
High-sensitivity methane detection based on QEPAS and H-QEPAS technologies combined with a self-designed 8.7 kHz quartz tuning fork [PDF]
Photoacoustics, 2023 Methane (CH4) is a greenhouse gas as well as being flammable and explosive. In this manuscript, quartz-enhanced photoacoustic spectroscopy (QEPAS) and heterodyne QEPAS (H-QEPAS) exploring a self-designed quartz tuning fork (QTF) with resonance frequency (
Tiantian Liang +4 more
doaj +5 more sources
Photoacoustics, 2023 In this work, a comparison between Quartz Enhanced Photoacoustic Spectroscopy (QEPAS) and Beat Frequency-QEPAS (BF-QEPAS) techniques for environmental monitoring of pollutants is reported.
Spagnolo Vincenzo +2 more
exaly +6 more sources
Planar Laser-Based QEPAS Trace Gas Sensor [PDF]
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.
Rui Sun, Frank Tittel
exaly +8 more sources
High-Power DFB Diode Laser-Based CO-QEPAS Sensor: Optimization and Performance
Sensors, 2018 A highly sensitive carbon monoxide (CO) trace gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) was demonstrated. A high-power distributed feedback (DFB), continuous wave (CW) 2.33 μm diode laser with an 8.8 mW output power was used ...
Yao Tong, Xin Yu
exaly +4 more sources
Improving the Signal to Noise Ratio of QTF Preamplifiers Dedicated for QEPAS Applications
Applied Sciences (Switzerland), 2020 The signal-to-noise ratio (SNR) is a major factor that limits the detection sensitivity of quartz-enhanced photoacoustic spectroscopy (QEPAS) sensors. The higher the electrical signal level compared to the noise amplitude is the lower the concentration ...
Tomasz Starecki +2 more
exaly +4 more sources
Sensors, 2017 All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS) applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations.
Tomasz Starecki +1 more
exaly +4 more sources
Towards low-cost QEPAS sensors for nitrogen dioxide detection
Photoacoustics, 2020 Increasing awareness of the adverse health effects of air pollution leads to a demand of low-cost sensors for the measurement of pollutants such as NO2.
Markus Knoll +2 more
exaly +5 more sources
SNR Improvement of QEPAS System by Preamplifier Circuit Optimization and Frequency Locked Technique
Photonic Sensors, 2018 Preamplifier circuit noise is of great importance in quartz enhanced photoacoustic spectroscopy (QEPAS) system. In this paper, several noise sources are evaluated and discussed in detail.
Zongliang Wang +2 more
exaly +4 more sources
Optomechanical energy enhanced BF-QEPAS for fast and sensitive gas sensing [PDF]
PhotoacousticsTraditional beat frequency quartz-enhanced photoacoustic spectroscopy (BF-QEPAS) are limited by short energy accumulation times and the necessity of a decay period, leading to weaker signals and longer measurement cycles.
Weilin Ye +5 more
doaj +3 more sources