A novel image-guided FT-IR sensor using chalcogenide glass optical fibers for the detection of combustion gases

An optical-fiber-based sensor suitable for the detection of combustion gases was designed and experimentally implemented with state-of-the-art sensitivity and capabilities. The system can not only provide imaging capability, but also provide spectral capability of the field of view (FOV) center guided by the imaging. The sensor employs a Fourier transform infrared (FT-IR) spectrometer, coupled with chalcogenide glass optical fiber, and a specially designed infrared optic lens. A special kit provided by Bruker Optics is connected on the spectrometer to focus the infrared beam from the lens at the entry of the fiber. It was tested in situ, in real time, under real-world conditions. Since each gas shows a characteristic optical emission spectrum, it is possible to detect selectively and quantitatively the presence of gases in combustion environment by analyzing mid-IR spectra. Spectral investigation techniques based on spectral shape band intensities and areas are tested to find the most effective tool for monitoring combustion gases. A comparison with experimental data has demonstrated that this sensor is well designed to study gases coming from combustion processes.