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Show AMERICAN FLAME RESEARCH COMWTTEE, 1992 INTERNATIONAL SYMPOSIUM ON EMISSIONS REDUCTION AND ENERGY CONSERVATION: RECENT PROGRESS IN COMBUSTION TECHNOLOGY, CAMBRIDGE, MA, OCTOBER 19-21 , 1992 FEASIBILITY OF OPTICAL COMBUSTION EXHAUST TRACE GAS MEASUREMENTS Introduction J. Wormhoudt and K. D. Annen Center for Chemical and Environmental Physics Aerodyne Research, Inc. 45 Manning Road Billerica, MA 01821 Measurements of the concentrations of trace molecular species in combustion exhaust systems are needed to address issues of environmental pollution and energy efficiency. Several techniques based on the absorption of various frequencies of light offer the potential for accurate, nonintrusive observations. Furthermore, ongoing development has resulted in the availability of essentially off-the-shelf commercial systems capable of field measurements of the sort that a few years ago could be accomplished only by much more expensive, custom-designed equipment. We have been involved in a number of recent projects requiring us to estimate the detectability of a number of trace gas species. This paper represents an extract of that work, reporting results of detailed feasibility calculations for measurements of combustion exhaust gaseous pollutants in the 1-100 ppm concentration range. Although the primary source for these calculations was an investigation of the feasibility of characterizing aircraft engine exhausts, the calculations of peak absorption levels and spectral interferences presented here apply to any combustion exhaust gas stream. Diagnostic Techniques Table 1 presents a list of techniques which might be considered to quantitatively measure a wide variety of molecular species. In the present application we will not consider mass spectrometry or the visible laser based techniques (LIF, CARS, and so forth), in part because the apparatus involved is further from the ideal of being field-capable. without modification from what is commercially available, and in part because the issues involved in calibrating these techniques 1 |
