Browsing by Subject "Gas absorption"

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    All-chalcogenide variable infrared filter
    (SPIE, 2009) Kondakcı, H. Esat; Köyle, Özlem; Yaman, Mecit; Dana, Aykutlu; Bayındır, Mehmet
    We present the design, fabrication, characterization of spatially variable infrared filter and a demonstration of the filter as a simple infrared spectrometer. A varying photonic band gap filter which consists of thermally evaporated, high refractive index contrast amorphous chalcogenide glass multilayers, makes the structure suitable to be used as spectrometer. Due to graded thickness structure, the filter exhibits a position dependent stop band and a cavity mode ranging from 2 to 8 μm wavelengths. It is demonstrated that the filter can be used to detect absorption peaks of common gases in the cavity mode range of the filter. © 2009 SPIE.
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    VOC gas leak detection using pyro-electric infrared sensors
    (IEEE, 2010) Erden, Fatih; Soyer, E. B.; Toreyin, B. U.; Çetin, A. Enis
    In this paper, we propose a novel method for detecting and monitoring Volatile Organic Compounds (VOC) gas leaks by using a Pyro-electric (or Passive) Infrared (PIR) sensor whose spectral range intersects with the absorption bands of VOC gases. A continuous time analog signal is obtained from the PIR sensor. This signal is discretized and analyzed in real time. Feature parameters are extracted in wavelet domain and classified using a Markov Model (MM) based classifier. Experimental results are presented. ©2010 IEEE.