A nitrogen oxides (NOx) and sulfur dioxide (SO₂) gas analyzer using deep ultraviolet (DUV) and violet light- emitting diodes (LEDs) is developed. The LEDs with wavelengths of 280 nm and 400 nm were alternately turned on to detect SO₂ and nitrogen dioxide (NO₂) absorption. Nitric oxide (NO) was converted to NO₂ with an ozonizer. In order to reduce water interference caused by water adsorption onto an inner surface of a gas ow cell, collimating optics reducing re ected lights were designed. As a result, less than 1% by full scale (%F.S.) of uctuation, 2%F.S. of drift and 0.5%F.S. of water interference were achieved in 0-50 ppm concentration range. Conversion efficiency from NO to NO₂ was over 95%.

Date Published: 27 February 2014
PDF: 6 pages
Proc. SPIE 9003, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XVIII, 90031F (27 February 2014); doi: 10.1117/12.2036159

Published in SPIE Proceedings Vol. 9003:
Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XVIII
Klaus P. Streubel; Heonsu Jeon; Li-Wei Tu; Martin Strassburg, Editor(s)