منابع مشابه
Sub-ppm multi-gas photoacoustic sensor.
A photoacoustic multi-gas sensor using tuneable laser diodes in the near-infrared region is reported. An optimized resonant configuration based on an acoustic longitudinal mode is described. Automatic tracking of the acoustic resonance frequency using a piezo-electric transducer and a servo electronics is demonstrated. Water vapour, methane and hydrogen chloride have been measured at sub-ppm le...
متن کاملSub-ppm multi gas sensing based on photoacoustic spectroscopy using DFB laser diodes
Sensitive photoacoustic detection of methane (CH4), hydrogen chloride (HCl) and water vapour (H2O) in the near-infrared range using semiconductor DFB lasers is reported. A detection limit of 0.17 ppm of CH4, 0.2 ppm of HCl and 0.024 ppm of H2O (signal-to-noise ratio = 3) is reached using a properly designed photoacoustic cell operating in its first longitudinal mode.
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An indium nitride (InN) gas sensor of 10 nm in thickness has achieved detection limit of 0.4 ppm acetone. The sensor has a size of 1 mm by 2.5 mm, while its sensing area is 0.25 mm by 2 mm. Detection of such a low acetone concentration in exhaled breath could enable early diagnosis of diabetes for portable physiological applications. The ultrathin InN epilayer extensively enhances sensing sensi...
متن کاملPhotoacoustic Photonic Crystal Fiber Gas Sensor
by Raymond Chen S.B. E.E., M.I.T., 2006 Submitted to the Department of Electrical Engineering and Computer Science in Partial Fulfillment of the Requirements for the Degree of Master of Engineering in Electrical Engineering and Computer Science at the Massachusetts Institute of Technology February, 2007 Copyright @2007 Raymond Chen. All rights reserved. The author hereby grants to MIT permissio...
متن کاملNear-infrared Quartz Enhanced Photoacoustic Sensor for Sub-ppm Level H2S Detection based on a Fiber-amplifier Source
An enhanced near-infrared quartz enhanced photoacoustic spectroscopy (QEPAS) sensor for subppm level H2S detection by means of a fiber amplified 1582 nm distributed feedback laser was developed. Experimental studies demonstrated that a H2S detection sensitivity of 142 ppbv can be achieved by the reported power-boosted QEPAS sensor at atmospheric pressure and room temperature. OCIS codes: (280.3...
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ژورنال
عنوان ژورنال: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
سال: 2006
ISSN: 1386-1425
DOI: 10.1016/j.saa.2005.10.034