Calibration-free scanned wavelength modulation spectroscopy – application to H2O and temperature sensing in flames
2015 (English)In: Optics Express, ISSN 1094-4087, Vol. 23, no 12, 16492-16499 p.Article in journal (Refereed) Published
A calibration-free scanned wavelength modulation spectroscopy scheme requiring minimal laser characterization is presented. Species concentration and temperature are retrieved simultaneously from a single fit to a group of 2f/1f-WMS lineshapes acquired in one laser scan. The fitting algorithm includes a novel method to obtain the phase shift between laser intensity and wavelength modulation, and allows for a wavelengthdependent modulation amplitude. The scheme is demonstrated by detection of H2O concentration and temperature in atmospheric, premixed CH4/air flat flames using a sensor operating near 1.4 μm. The detection sensitivity for H2O at 2000 K was 4 × 10−5 cm−1 Hz-1/2, and temperature was determined with a precision of 10 K and absolute accuracy of ~50 K. A parametric study of the dependence of H2O and temperature on distance to the burner and total fuel mass flow rate shows good agreement with 1D simulations.
Place, publisher, year, edition, pages
2015. Vol. 23, no 12, 16492-16499 p.
Atom and Molecular Physics and Optics Energy Systems
IdentifiersURN: urn:nbn:se:umu:diva-105147DOI: 10.1364/OE.23.016492ISI: 000356902500128OAI: oai:DiVA.org:umu-105147DiVA: diva2:823570