skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: In situ measurements of nitric oxide in coal-combustion exhaust using a sensor based on a widely tunable external-cavity GaN diode laser

Journal Article · · Applied Optics
DOI:https://doi.org/10.1364/AO.46.003946· OSTI ID:20939568
; ; ; ;  [1]
  1. Purdue University, West Lafayette, IN (United States). School of Mechanical Engineers

A diode-laser-based sensor has been developed to measure nitric oxide mole fractions using absorption spectroscopy. The sensor is based on sum-frequency mixing of a 395 nm external-cavity diode laser (ECDL) and a 532 run laser in a beta-barium-borate crystal. Using a new tuning scheme, the GaN ECDL wavelength was modulated over 90 GHz without mode hops. The sensor was applied for measurements of the NO mole fraction in the exhaust of a laboratory-scale, 30 kW, coal-fired boiler burner. Absorption measurements were successfully performed despite severe attenuation by scattering from ash particles in the exhaust stream and on the exhaust-section windows. A detection limit (1 sigma) of 4.5 ppm m/root Hz at 700 K was demonstrated in coal-combustion exhaust at a maximum detection rate of 5 Hz.

OSTI ID:
20939568
Journal Information:
Applied Optics, Vol. 46, Issue 19; ISSN 0003-6935
Country of Publication:
United States
Language:
English