Calibration-free wavelength-modulation spectroscopy for measurements of gas temperature and concentration in harsh environments.

We present a practical implementation of calibration-free wavelength-modulation spectroscopy with second harmonic detection (WMS-2f) for measurements of gas temperature and concentration in harsh environments. The method is applicable to measurements using lasers with synchronous wavelength and intensity modulation (such as injection current-tuned diode lasers). The key factors that enable measurements without the on-site calibration normally associated with WMS are (1) normalization of the WMS-2f signal by the first harmonic (1f) signal to account for laser intensity, and (2) the inclusion of laser-specific tuning characteristics in the spectral-absorption model that is used to compare with measured 1f-normalized, WMS-2f signals to infer gas properties. The uncertainties associated with the calibration-free WMS method are discussed, with particular emphasis on the influence of pressure and optical depth on the WMS signals. Many of these uncertainties are also applicable to calibrated WMS measurements. An example experimental setup that combines six tunable diode laser sources between 1.3 and 2.0 mum into one probe beam for measurements of temperature, H(2)O, and CO(2) is shown. A hybrid combination of wavelength and frequency demultiplexing is used to distinguish among the laser signals, and the optimal set of laser-modulation waveforms is presented. The system is demonstrated in the harsh environment of a ground-test scramjet combustor. A comparison of direct absorption and 1f-normalized, WMS-2f shows a factor of 4 increase in signal-to-noise ratio with the WMS technique for measurements of CO(2) in the supersonic flow. Multidimensional computational fluid-dynamics (CFD) calculations are compared with measurements of temperature and H(2)O using a simple method that accounts for the influence of line-of-sight (LOS) nonuniformity on the absorption measurements. The comparisons show the ability of the LOS calibration-free technique to gain useful information about multidimensional CFD models.

[1]  M. Cappelli,et al.  Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode. , 2010, Physics of plasmas.

[2]  Ronald K. Hanson,et al.  Measurements of high-pressure CO2 absorption near 2.0 μm and  implications on tunable diode laser sensor design , 2009 .

[3]  Ronald K. Hanson,et al.  Diode laser-based detection of combustor instabilities with application to a scramjet engine , 2009 .

[4]  Ronald K. Hanson,et al.  LASER-BASED MEASUREMENTS OF OH, TEMPERATURE, AND WATER VAPOR CONCENTRATION IN A HYDROCARBON-FUELED SCRAMJET (POSTPRINT) , 2008 .

[5]  Uwe Rascher,et al.  Absolute, high resolution water transpiration rate measurements on single plant leaves via tunable diode laser absorption spectroscopy (TDLAS) at 1.37 μm , 2008 .

[6]  V. Malathy Devi,et al.  Spectroscopic database of CO2 line parameters: 4300–7000 cm−1 , 2008 .

[7]  W. Johnstone,et al.  Tunable Diode Laser Spectroscopy With Wavelength Modulation: A Phasor Decomposition Method for Calibration-Free Measurements of Gas Concentration and Pressure , 2008, Journal of Lightwave Technology.

[8]  W. Johnstone,et al.  Tunable Diode-Laser Spectroscopy With Wavelength Modulation: A Calibration-Free Approach to the Recovery of Absolute Gas Absorption Line Shapes , 2007, Journal of Lightwave Technology.

[9]  Pierre Sagaut,et al.  Time-Frequency Analysis and Detection of Supersonic Inlet Buzz , 2007 .

[10]  Noel T. Clemens,et al.  An experimental investigation of supersonic inlet unstart , 2007 .

[11]  Ronald K. Hanson,et al.  A diode laser sensor for rapid, sensitive measurements of gas temperature and water vapour concentration at high temperatures and pressures , 2007 .

[12]  M. Lackner.  TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY (TDLAS) IN THE PROCESS INDUSTRIES – A REVIEW , 2007 .

[13]  Ronald K. Hanson,et al.  Measurements of near-IR water vapor absorption at high pressure and temperature , 2007 .

[14]  Ronald K. Hanson,et al.  Measurements of spectral parameters of water-vapour transitions near 1388 and 1345 nm for accurate simulation of high-pressure absorption spectra , 2007 .

[15]  Ronald K. Hanson,et al.  Measurement of Nonuniform Temperature Distributions Using Line-of-Sight Absorption Spectroscopy , 2007 .

[16]  Ronald K. Hanson,et al.  Sensing and Control of Combustion Instabilities in Swirl-Stabilized Combustors Using Diode-Laser Absorption , 2006 .

[17]  Doug Davis,et al.  Diode Laser Absorption Tomography of 2D Supersonic Flow , 2007 .

[18]  Ronald K. Hanson,et al.  Active control of lean blowout in a swirl-stabilized combustor using a tunable diode laser , 2007 .

[19]  Ronald K. Hanson,et al.  Rapid measurements of temperature and H2O concentration in IC engines with a spark plug-mounted diode laser sensor , 2007 .

[20]  Ronald K. Hanson,et al.  In-cylinder gas temperature and water concentration measurements in HCCI engines using a multiplexed-wavelength diode-laser system: Sensor development and initial demonstration , 2007 .

[21]  R. Hanson,et al.  Tunable mid-IR laser absorption sensor for time-resolved hydrocarbon fuel measurements , 2007 .

[22]  Kuo-Cheng Lin,et al.  Diode Laser Diagnostics for High Speed Flows , 2006 .

[23]  V. Malathy Devi,et al.  Self-broadened widths and shifts of 12C16O2: 4750–7000 cm−1 , 2006 .

[24]  Luc Thévenaz,et al.  Diode laser frequency stabilisation for water-vapour differential absorption sensing , 2006 .

[25]  Mark Gruber,et al.  Simulating Inlet Distortion Effects In A Direct-Connect Scramjet Combustor (Postprint) , 2006 .

[26]  Ronald K. Hanson,et al.  Diode Laser Sensors for Ground Testing , 2006 .

[27]  Hejie Li,et al.  Extension of wavelength-modulation spectroscopy to large modulation depth for diode laser absorption measurements in high-pressure gases. , 2006, Applied optics.

[28]  Jerry M. Seitzman,et al.  Absorption-based temperature-distribution-sensing for combustor diagnostics and control , 2006 .

[29]  Gang Li,et al.  The HITRAN 2008 molecular spectroscopic database , 2005 .

[30]  Tarun Mathur,et al.  Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor. , 2005, Applied optics.

[31]  A. Griffiths,et al.  Diode laser absorption spectroscopy of water vapor in a scramjet combustor. , 2005, Applied optics.

[32]  R. Hanson,et al.  Selection of NIR H2O absorption transitions for in-cylinder measurement of temperature in IC engines , 2005 .

[33]  Tim Lieuwen,et al.  Active Control of Lean Blowout for Turbine Engine Combustors , 2005 .

[34]  Jian Li,et al.  Thermoacoustic Flow Instability in a Scramjet Combustor , 2005 .

[35]  Ronald K. Hanson,et al.  Diode Laser Sensor for Gas Temperature and H2O Concentration in a Scramjet Combustor Using Wavelength Modulation Spectroscopy , 2005 .

[36]  Shepard A. Clough,et al.  Atmospheric radiative transfer modeling: a summary of the AER codes , 2005 .

[37]  Joachim Walewski,et al.  Wavelength-agile sensor applied for HCCI engine measurements , 2005 .

[38]  Vigor Yang,et al.  Combustion oscillations in a scramjet engine combustor with transverse fuel injection , 2005 .

[39]  Jonathan T. C. Liu,et al.  Large-modulation-depth 2f spectroscopy with diode lasers for rapid temperature and species measurements in gases with blended and broadened spectra. , 2004, Applied optics.

[40]  R. Engelbrecht.  A compact NIR fiber-optic diode laser spectrometer for CO and CO(2): analysis of observed 2f wavelength modulation spectroscopy line shapes. , 2004, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[41]  J. Hahn.  Untersuchung der Reaktion von Wasserstoffatomen mit Sauerstoffmolekülen (H+O2+M → HO2+M) in weiten Druck- und Temperaturbereichen , 2004 .

[42]  Ronald K. Hanson,et al.  Wavelength modulation absorption spectroscopy with 2 f detection using multiplexed diode lasers for rapid temperature measurements in gaseous flows , 2004 .

[43]  A discussion about the significance of Absorbance and sample optical thickness in conventional absorption spectrometry and wavelength-modulated laser absorption spectrometry , 2003 .

[44]  Luc Thévenaz,et al.  Wavelength modulation spectroscopy: combined frequency and intensity laser modulation. , 2003, Applied optics.

[45]  B. D. Green,et al.  Handheld, battery-powered near-IR TDL sensor for stand-off detection of gas and vapor plumes , 2003, Conference on Lasers and Electro-Optics, 2003. CLEO '03..

[46]  O. Axner,et al.  Improved detectability of wavelength modulation diode laser absorption spectrometry applied to window-equipped graphite furnaces by 4th and 6th harmonic detection , 2003 .

[47]  Volker Ebert,et al.  Digital, phase-sensitive detection for in situ diode-laser spectroscopy under rapidly changing transmission conditions , 2002 .

[48]  T. Fernholz,et al.  In situ detection of potassium atoms in high-temperature coal-combustion systems using near-infrared-diode lasers. , 2002, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[49]  P. Werle,et al.  Spectroscopic gas analyzers based on indium-phosphide, antimonide and lead-salt diode-lasers. , 2002, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[50]  Philip A Martin,et al.  Near-infrared diode laser spectroscopy in chemical process and environmental air monitoring. , 2002, Chemical Society reviews.

[51]  Sébastien Candel,et al.  Combustion control and sensors: a review , 2002 .

[52]  Jeffrey M. Donbar,et al.  Newly Developed Direct-Connect High-Enthalpy Supersonic Combustion Research Facility , 2001 .

[53]  T. Aizawa.  Diode-Laser Wavelength-Modulation Absorption Spectroscopy for Quantitative in situ Measurements of Temperature and OH Radical Concentration in Combustion Gases. , 2001, Applied optics.

[54]  Jörgen Gustafsson,et al.  Wavelength modulation absorption spectrometry — an extensive scrutiny of the generation of signals , 2001 .

[55]  R. Hanson,et al.  Diode-Laser Absorption Sensor for Line-of-Sight Gas Temperature Distributions. , 2001, Applied optics.

[56]  Amin N. Dharamsi,et al.  Frequency stabilization of a diode laser to absorption lines of water vapor in the 944-nm wavelength region , 2001 .

[57]  O. Axner,et al.  Characterization of background signals in wavelength-modulation spectrometry in terms of a fourier based theoretical formalism. , 2001, Applied optics.

[58]  J. M. Seitzman,et al.  Broadband Infrared Absorption Sensor for High-Pressure Combustor Control , 2000 .

[59]  W. Kessler,et al.  AIAA 2000-2452 Overview of Diode Laser Measurements in Large-Scale Test Facilities , 2000 .

[60]  Takaya Iseki,et al.  A portable remote methane sensor using a tunable diode laser , 2000 .

[61]  J. Henningsen,et al.  Quantitative wavelength-modulation spectroscopy without certified gas mixtures , 2000 .

[62]  R. Tipping,et al.  The density matrix of H2O–N2 in the coordinate representation: A Monte Carlo calculation of the far-wing line shape , 2000 .

[63]  Arash Ateshkadi,et al.  Lean blowout model for a spray-fired swirl-stabilized combustor , 2000 .

[64]  Ronald K. Hanson,et al.  Diode-laser sensor for monitoring multiple combustion parameters in pulse detonation engines , 2000 .

[65]  O. Axner,et al.  Theoretical description based on Fourier analysis of wavelength-modulation spectrometry in terms of analytical and background signals. , 1999, Applied optics.

[66]  C. Corsi,et al.  High-resolution measurements of line intensity, broadening and shift of CO around m , 1999 .

[67]  C. Boulet,et al.  Theoretical far-wing line shape and absorption for high-temperature CO2. , 1999, Applied optics.

[68]  D. Kane,et al.  Diode laser measurements of concentration and temperature in microgravity combustion , 1999 .

[69]  Takashi Shimura,et al.  LOAD OSCILLATIONS CAUSED BY UNSTART OF HYPERSONIC WIND TUNNELS AND ENGINES , 1998 .

[70]  D. Oh,et al.  Frequency Modulation Multiplexing for Simultaneous Detection of Multiple Gases by use of Wavelength Modulation Spectroscopy with Diode Lasers. , 1998, Applied optics.

[71]  M. Allen,et al.  Diode laser absorption sensors for gas-dynamic and combustion flows. , 1998, Measurement science & technology.

[72]  A. Larsson,et al.  Gas monitoring using semiconductor lasers operating in the 2 μm wavelength region , 1998 .

[73]  Peter Werle,et al.  A review of recent advances in semiconductor laser based gas monitors , 1998 .

[74]  Christian Oliver Paschereit,et al.  Control of thermoacoustic instabilities and emissions in an industrial-type gas-turbine combustor , 1998 .

[75]  V. Nagali.  Diode laser study of high-pressure water-vapor spectroscopy , 1998 .

[76]  Applications of wavelength-modulation spectroscopy in resolution of pressure and modulation broadened spectra , 1996 .

[77]  The frequency detuning and band‐average approximations in a far‐wing line shape theory satisfying detailed balance , 1996 .

[78]  Saied Emami,et al.  Unsteady pressure behavior in a ramjet/scramjet inlet , 1996 .

[79]  Yedidia Neumeier,et al.  Experimental demonstration of active control of combustion instabilities using real-time modes observation and secondary fuel injection , 1996 .

[80]  Richard H. Tipping,et al.  Theory of the water vapor continuum and validations , 1995 .

[81]  J. Scofield.  Frequency‐domain description of a lock‐in amplifier , 1994 .

[82]  Ronald K. Hanson,et al.  Laser diode wavelength-modulation spectroscopy for simultaneous measurement of temperature, pressure, and velocity in shock-heated oxygen flows. , 1993, Applied optics.

[83]  Jean-Michel Hartmann,et al.  The infrared continuum of pure water vapor: Calculations and high-temperature measurements , 1993 .

[84]  K. Uehara,et al.  Remote detection of methane with a 1.66-microm diode laser. , 1992, Applied optics.

[85]  J. A. Silver,et al.  Frequency-modulation spectroscopy for trace species detection: theory and comparison among experimental methods. , 1992, Applied optics.

[86]  J. A. Silver,et al.  Frequency modulation and wavelength modulation spectroscopies: comparison of experimental methods using a lead-salt diode laser. , 1992, Applied optics.

[87]  F. X. Kneizys,et al.  Line shape and the water vapor continuum , 1989 .

[88]  V. Menoux,et al.  Line shape in the low-frequency wing of self-broadened CO(2) lines. , 1987, Applied optics.

[89]  Daniel T. Cassidy,et al.  Atmospheric pressure monitoring of trace gases using tunable diode lasers. , 1982, Applied optics.

[90]  D. Labrie,et al.  Second-harmonic detection with tunable diode lasers — Comparison of experiment and theory , 1981 .

[91]  P. K. Falcone,et al.  Temperature measurement technique for high-temperature gases using a tunable diode laser. , 1978, Applied optics.

[92]  P. L. Kelley,et al.  Detection of Air Pollutants with Tunable Diode Lasers , 1971, Science.

[93]  D. E. Burch,et al.  The Shapes of Collision-Broadened CO2 Lines , 1968 .

[94]  S. S. Penner,et al.  Absorption coefficients for water vapor in the 600–1000 cm-1 region , 1968 .

[95]  P. Varanasi,et al.  Spectral absorption coefficients in the pure rotation spectrum of water vapor , 1967 .