The effects of thermal boundary layers on tunable diode laser absorption spectroscopy (TDLAS) measurement results must be quantified when using the line-of-sight (LOS) TDLAS under conditions with spatial temperature gradient. In this paper, a new methodology based on spectral simulation is presented quantifying the LOS TDLAS measurement deviation under conditions with thermal boundary layers. The effects of different temperature gradients and thermal boundary layer thickness on spectral collisional widths and gas concentration measurements are quantified. A CO2 TDLAS spectrometer, which has two gas cells to generate the spatial temperature gradients, was employed to validate the simulation results. The measured deviations and LOS averaged collisional widths are in very good agreement with the simulated results for conditions with different temperature gradients. We demonstrate quantification of thermal boundary layers’ thickness with proposed method by exploitation of the LOS averaged the collisional width of the path-integrated spectrum.
V. Ebert, J. Wolfrum. “Absorption Spectroscopy”. In: F. Mayinger, O. Feldmann, editors. Optical MeasurementsTechniques and Applications (Heat and Mass Transfer), 2nd corr. ed. Heidelberg, Mu¨nchen: Springer Verlag, 2001, pp. 227–265.
2.
NwabohJ.A.QuZ.WerhahnO.EbertV.“Interband Cascade Laser-Based Optical Transfer Standard for Atmospheric Carbon Monoxide Measurements”. Appl. Opt. 2017. 56(11): E84–E93.
3.
QuZ.SteinvallE.GhorbaniR.SchmidtF.M.“Tunable Diode Laser Atomic Absorption Spectroscopy for Detection of Potassium under Optically Thick Conditions”. Anal. Chem. 2016. 88(7): 3754–3760.
4.
GoldensteinC.S.SpearrinR.M.JeffriesJ.B.HansonR.K.“Infrared Laser-Absorption Sensing for Combustion Gases”. Prog. Energy Combust. Sci. 2017. 60: 132–176.
5.
HansonR.K.“Applications of Quantitative Laser Sensors To Kinetics, Propulsion And Practical Energy Systems”. Proc. Combust. Inst. 2011. 33(1): 1–40.
6.
OuyangX.VargheseP.L.“Line-of-Sight Absorption Measurements of High Temperature Gases with Thermal and Concentration Boundary Layers”. Appl. Opt. 1989. 28(18): 3979–3984.
7.
CięszczykS.“A Local Model and Calibration Set Ensemble Strategy for Open-Path FTIR Gas Measurement with Varying Temperature”. Metrol. Meas. Syst. 2013. 20(3): 513–524.
8.
QuZ.GhorbaniR.ValievD.SchmidtF.M.“Calibration-Free Scanned Wavelength Modulation Spectroscopy–Application to H2O and Temperature Sensing in Flames”. Opt. Express. 2015. 23(12): 16492–16499.
9.
WagnerS.FisherB.T.FlemingJ.W.EbertV.“TDLAS-Based In Situ Measurement of Absolute Acetylene Concentrations in Laminar 2D Diffusion Flames”. Proc. Combust. Inst. 2009. 32(1): 839–846.
10.
WangJ.MaiorovM.JeffriesJ.B.GarbuzovD.Z.et al.“A Potential Remote Sensor of CO in Vehicle Exhausts Using 2.3 µm Diode Lasers”. Meas. Sci. Technol. 2000. 11(11): 1576.
11.
SepmanA.ÖgrenY.QuZ.WiinikkaH.et al.“Real-Time In Situ Multi-Parameter TDLAS Sensing in the Reactor Core of an Entrained-Flow Biomass Gasifier”. Proc. Combust. Inst. 2017. 36(3): 4541–4548.
12.
WagnerS.KleinM.KathrotiaT.RiedelU.et al.“Absolute, Spatially Resolved, In Situ CO Profiles in Atmospheric Laminar Counter-Flow Diffusion Flames Using 2.3 µm TDLAS”. Appl. Phys. B. 2012. 109(3): 533–540.
13.
GirardJ.SpearrinR.GoldensteinC.HansonR.K.“Compact Optical Probe for Flame Temperature and Carbon Dioxide Using Interband Cascade Laser Absorption Near 4.2 µm”. Combust. Flame. 2017. 178: 158–167.
14.
SunK.SurR.ChaoX.JeffriesJ.B.et al.“TDL Absorption Sensors for Gas Temperature and Concentrations in a High-Pressure Entrained-Flow Coal Gasifier”. Proc. Combust. Inst. 2013. 34(2): 3593–3601.
15.
GoldensteinC.S.AlmodóvarC.A.JeffriesJ.B.HansonR.K.et al.“High-Bandwidth Scanned-Wavelength-Modulation Spectroscopy Sensors for Temperature and H2O in a Rotating Detonation Engine”. Meas. Sci. Technol. 2014. 25(10): 105104.
16.
GoldensteinC.S.SchultzI.A.JeffriesJ.B.HansonR.K.“Two-Color Absorption Spectroscopy Strategy for Measuring the Column Density and Path Average Temperature of the Absorbing Species in Nonuniform Gases”. Appl. Opt. 2013. 52(33): 7950–7962.
17.
LiF.YuX.CaiW.MaL.“Uncertainty in Velocity Measurement Based on Diode-Laser Absorption in Nonuniform Flows”. Appl. Opt. 2012. 51(20): 4788–4797.
18.
ChangL.S.StrandC.L.JeffriesJ.B.HansonR.K.et al.“Supersonic Mass-Flux Measurements via Tunable Diode Laser Absorption and Nonuniform Flow Modeling”. AIAA J. 2011. 49(12): 2783–2791.
19.
SchoenungM.HansonR.K.“CO and Temperature Measurements in a Flat Flame by Laser Ab orption Spectroscopy and Probe Techniques”. Combust. Sci. Technol. 1980. 24(5–6): 227–237.
20.
CaiW.KaminskiC.F.“Tomographic Absorption Spectroscopy For The Study Of Gas Dynamics And Reactive Flows”. Prog. Energy Combust. Sci. 2017. 59: 1–31.
21.
LiuX.JeffriesJ.B.HansonR.K.“Measurement of Non-Uniform Temperature Distributions Using Line-of-Sight Absorption Spectroscopy”. AIAA J. 2007. 45(2): 411–419.
22.
SandersS.T.WangJ.JeffriesJ.B.HansonR.K.“Diode-Laser Absorption Sensor for Line-Of-Sight Gas Temperature Distributions”. Appl. Opt. 2001. 40(24): 4404–4415.
23.
LiuC.XuL.CaoZ.“Measurement of Nonuniform Temperature and Concentration Distributions by Combining Line-of-Sight Tunable Diode Laser Absorption Spectroscopy with Regularization Methods”. Appl. Opt. 2013. 52(20): 4827–4842.
24.
SeidelA.WagnerS.DreizlerA.et al.“Robust, Spatially Scanning, Open-Path TDLAS Hygrometer Using Retro-Reflective Foils for Fast Tomographic 2-D Water Vapor Concentration Field Measurements”. Atmos. Meas. Tech. 2015. 8(5): 2061–2068.
25.
PogányA.WagnerS.WerhahnO.EbertV.“Development and Metrological Characterization of a Tunable Diode Laser Absorption Spectroscopy (TDLAS) Spectrometer for Simultaneous Absolute Measurement of Carbon Dioxide and Water Vapor”. Appl. Spectrosc. 2015. 69(2): 257–268.
26.
N. Lüttschwager, A. Pogány, J. Nwaboh, A. Klein, B. et al. “Traceable amount of substance fraction measurements in gases through infrared spectroscopy at PTB”. In: 17th International Congress of Metrology. Paris, France: September 21–24, 2015. Pp. 07005.
PogányA.OttO.WerhahnO.EbertV.“Towards Traceability in CO2 Line Strength Measurements by TDLAS at 2.7 µm”. J. Quant. Spectrosc. Radiat. Transfer. 2013. 130: 147–157.
