Water vapor measurements for combustion diagnostics using a 1350-nm tunable diode laser

1994 ◽  
Author(s):  
Liang-Guo Wang ◽  
Richard E. Trucco ◽  
Glen W. Sachse ◽  
Richard E. Campbell ◽  
Richard E. Davis
Keyword(s):  
Water Vapor ◽  
Diode Laser ◽  
Tunable Diode Laser ◽  
Combustion Diagnostics

Evaluation of tunable diode laser absorption spectroscopy for in‐process water vapor mass flux measurements during freeze drying

2007 ◽  
Vol 96 (7) ◽  
pp. 1776-1793 ◽  
Author(s):  
Henning Gieseler ◽  
William J. Kessler ◽  
Michael Finson ◽  
Steven J. Davis ◽  
Phillip A. Mulhall ◽  
...  
Keyword(s):  
Water Vapor ◽  
Diode Laser ◽  
Absorption Spectroscopy ◽  
Mass Flux ◽  
Freeze Drying ◽  
Tunable Diode Laser ◽  
Laser Absorption ◽  
Flux Measurements ◽  
Diode Laser Absorption ◽  
Vapor Mass

scholarly journals In-situ measurement of water-vapor in fire environments using a real-time tunable diode laser based system

2020 ◽  
pp. 103114
Author(s):  
Shruti Ghanekar ◽  
Rajavasanth Rajasegar ◽  
Nicholas Traina ◽  
Constandinos Mitsingas ◽  
Richard M. Kesler ◽  
...  
Keyword(s):  
Water Vapor ◽  
Real Time ◽  
Diode Laser ◽  
In Situ Measurement ◽  
Tunable Diode Laser ◽  
In Fire

Measurement of Total Water with a Tunable Diode Laser Hygrometer: Inlet Analysis, Calibration Procedure, and Ice Water Content Determination

2007 ◽  
Vol 24 (3) ◽  
pp. 463-475 ◽  
Author(s):  
Sean M. Davis ◽  
A. Gannet Hallar ◽  
Linnea M. Avallone ◽  
William Engblom
Keyword(s):  
Particle Size ◽  
Water Vapor ◽  
Water Content ◽  
Diode Laser ◽  
Tunable Diode Laser ◽  
Calibration Data ◽  
Total Water ◽  
Wide Range ◽  
Ice Water Content ◽  
Ice Water

Abstract The University of Colorado closed-path tunable diode laser hygrometer (CLH), a new instrument for the in situ measurement of enhanced total water (eTW, the sum of water vapor and condensed water enhanced by a subisokinetic inlet), has recently been flown aboard the NASA DC-8 and WB-57F aircrafts. The CLH has the sensitivity necessary to quantify the ice water content (IWC) of extremely thin subvisual cirrus clouds (∼0.1 mg m−3), while still providing measurements over a large range of conditions typical of upper-tropospheric cirrus (up to 1 g m−3). A key feature of the CLH is its subisokinetic inlet system, which is described in detail in this paper. The enhancement and evaporation of ice particles that results from the heated subisokinetic inlet is described both analytically and based on computational fluid dynamical simulations of the flow around the aircraft. Laboratory mixtures of water vapor with an accuracy of 2%–10% (2σ) were used to calibrate the CLH over a wide range of water vapor mixing ratios (∼50–50 000 ppm) and pressures (∼100–1000 mb). The water vapor retrieval algorithm, which is based on the CLH instrument properties as well as on the spectroscopic properties of the water absorption line, accurately fits the calibration data to within the uncertainty of the calibration mixtures and instrument signal-to-noise ratio. A method for calculating cirrus IWC from the CLH enhanced total water measurement is presented. In this method, the particle enhancement factor is determined from an independent particle size distribution measurement and the size-dependent CLH inlet efficiency. It is shown that despite the potentially large uncertainty in particle size measurements, the error introduced by this method adds ∼5% error to the IWC calculation. IWC accuracy ranges from 20% at the largest IWC to 50% at small IWC (<5 mg m−3).

Optical Remote Sensing of Oxygen and Water Vapor Concentration in PEMFC Channel by Using Tunable Diode Laser Absorption Spectroscopy Techniques

2007 ◽  
Author(s):  
Yoshinobu Fujii ◽  
Shohji Tsushima ◽  
Shuichiro Hirai
Keyword(s):  
Remote Sensing ◽  
Water Vapor ◽  
Diode Laser ◽  
Absorption Spectroscopy ◽  
Tunable Diode Laser ◽  
Vapor Concentration ◽  
Optical Remote Sensing ◽  
Water Vapor Concentration ◽  
Laser Absorption ◽  
Diode Laser Absorption

In this study, we present optical remote sensing of oxygen and water vapor concentration in gas flow channels in an operating polymer electrolyte membrane fuel cell (PEMFC) by using Tunable Diode Laser Absorption Spectroscopy (TDLAS). Wavelengths of the diode laser are 1392nm for measurement of water vapor concentration and 760nm for measurement of oxygen concentration, respectively. We demonstrated that the optical remote sensing based on TDLAS techniques could detect variation of oxygen and water vapor concentration in the PEMFC channel.

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