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Visible Infra‐red Double Extinction Measurements in Densely Laden Media, New Progress
Author(s) -
Gouesbet Gérard,
Gougeon Patrick,
Le Toulouzan JeanNoël,
Thioye Massamba,
Guidt JeanBernard
Publication year - 1988
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.19880050201
Subject(s) - extinction (optical mineralogy) , light scattering , optics , wavelength , materials science , scattering , particle size , visible spectrum , range (aeronautics) , particle (ecology) , physics , chemistry , geology , composite material , oceanography
This paper describes new progress obtained with an optical technique called V.I.D.E. (Visible Infra‐red Double Extinction) which simultaneously measures mean particle size in the range of 10–120 μm and mean number density in densely laden media (up to 0.1% volume fraction). The underlying theory, taking account of multiple light scattering, is recalled. Simultaneous size and concentration measurements are obtained by simultaneously recording transmittances of the medium at two well chosen wavelengths. Experimental results for suspensions of glass particles in air, are described and discussed. The size of particles given by the technique agrees with that given by optical microscopy and Malvern diffractometry. The V.I.D.E. technique is shown to be very suitable to investigate dense media whose optical thickness is up to nine and for which other techniques fail.