In the investigation of the considerable absorption of visible light in ind
ustrially rolled aluminium surfaces, a thorough knowledge of the total refl
ectance measurement method is required. In this paper a general introductio
n to the integrating sphere method is given, with emphasis on the current u
nderstanding of instrumental artefacts and ways of correcting them. Selecte
d aluminium surfaces were measured employing two spheres; a single-beam ins
trument equipped with a white-light source and a Si-photoelement detector,
and a double-beam sphere, which measures reflectance properties with spectr
al resolution. It was found necessary to take precautions concerning the or
ientation of rolled samples relative instrument geometry, to avoid artifici
al losses from the sphere. The use of a specular reference standard is assu
med to minimise the effect of several sphere artefacts, since it produces s
imilar angular distribution of reflected light as the rather glossy alumini
um samples. Measurements with spectral resolution show that the total refle
ctance of aluminium is somewhat red shifted after rolling, a tendency that
cannot be revealed in ordinary white-light measurements. (C) 2000 Elsevier
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