Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Quantitative IBBCEAS measurements of I2 in the presence of aerosols

Abstract : An instrument implementing Incoherent BroadBand Cavity-Enhanced Absorption Spectroscopy (IBBCEAS) for quantitative measurements of molecular iodine (I2) at ambient pressure and in the presence of aerosols is presented. The instrument is based on a LED emitting in the green spectral region around 500–550 nm, exciting a multitude of rovibronic transitions in the I2 B ← X electronic absorption spectrum. I2 was generated using a permeation device and was mixed with a dilution flow of Ar and another flow containing NaCl aerosols. Retrieval of the mirror reflectivity, necessary for quantitative IBBCEAS measurements, was not pursued in this study. Instead, calibrated I2 flows were used, and a differential optical absorption spectroscopy type of algorithm was implemented for the data analysis. This approach has several benefits, in particular when light extinction due to aerosols is substantial. Estimated detection limits are roughly 0.04 nmol/l without aerosols and 0.4 nmol/l in the presence of aerosols (1010 particles/l with 60–70 nm mean diameter, leading to I 0/I aerosols ≈ 5.4). A drop in measured I2 concentration in relation to the expected mixing ratio was observed when using the highest aerosol concentration, likely due to adsorption of I2 onto aerosols.
Liste complète des métadonnées
Contributeur : Lilloa Université de Lille Connectez-vous pour contacter le contributeur
Soumis le : lundi 5 octobre 2020 - 13:44:01
Dernière modification le : mardi 19 octobre 2021 - 23:32:41




Olof Johansson, Hervé Mutelle, Alexander E. Parker, Sebastien Batut, Pascal Demaux, et al.. Quantitative IBBCEAS measurements of I2 in the presence of aerosols. Applied Physics B - Laser and Optics, Springer Verlag, 2014, Applied Physics B. Lasers and Optics, 114, pp.421-432. ⟨10.1007/s00340-013-5536-9⟩. ⟨hal-02957771⟩