appareil pour mesurer la fixité de teinte
- Domaine
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- industrie papetière matériel d'essai du papier
- Dernière mise à jour
Terme privilégié :
- appareil pour mesurer la fixité de teinte n. m.
Terme utilisé dans certains contextes :
- appareil pour mesurer la solidité de coloration n. m.
Traductions
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anglais
Auteur : Office québécois de la langue française,Définition
((...)) in which a very high intensity of light is reached by placing both the specimen to be tested and the incandescent wire of a gas-filled Wolfram lamp in the two foci of an ellipsoid concave mirror, so that a very large proportion of the rays emitted by the incandescent wire are reflected on the trial surface. As the cavity of the mirror is filled with water and a correction filter or screen is inserted in the trajectory of the rays, not only is a great proportion of the heat rays absorbed but the light striking the specimen is, in composition, a good reproduction of the sun's rays. The intensity of the light thus falling on the paper under test is approximately 35 times that of sunlight (at noon in midsummer, temperature latitude, from a cloudless sky) so that the alteration of the specimen after exposure can be compared with that of sunlight.
Note :
The "fastness" to light may on the one hand be indicated by the number of "sun-hours" at which the specimen shows the first trace of fading or discoloration, while on the other hand an appreciation may be given of this discoloration of the specimen after a continuous exposure of say 48 "sun-hours".
Terme :
- apparatus for testing degree of fastness of paper to light