Development of multireflection absorption spectroscopy device using ultraviolet LEDs

An ultraviolet absorption spectroscopy device using light‐emitting diodes (LEDs) as the light source was constructed. The measurement cell, light source, and transmitting and receiving optics were installed on a breadboard measuring 30 × 30 cm. A measurement optical path length of 1 m was made possible by multireflection optics. The device can mount two LEDs in tandem, and the transmitted light is coupled to an optical fiber, which is connected to a compact spectrometer. Two LEDs with center wavelengths of 280 and 295 nm were used to provide an emission spectrum which covered the peak region of the absorption spectrum of SO 2 . Experiments confirmed the linearity of the absorption coefficient measured by the device for SO 2 concentrations in the range of 16 to 800 ppm. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(12): 62–68, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/ecj.11419