Premium
EFFECT OF VIEWING BACKGROUND ON TURBIDITY PERCEPTION THRESHOLDS
Author(s) -
FLEET CHRISTINE F.,
SIEBERT KARL J.
Publication year - 2006
Publication title -
journal of sensory studies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 53
eISSN - 1745-459X
pISSN - 0887-8250
DOI - 10.1111/j.1745-459x.2006.00051.x
Subject(s) - turbidity , white light , mathematics , materials science , optics , chemistry , analytical chemistry (journal) , chromatography , physics , biology , ecology
ABSTRACT Colloidal‐size synthetic‐polymer microspheres of three sizes (0.15, 0.31 and 0.70‐µm diameter) were each suspended in liquids of three different colors (clear, tan and dark brown) at a range of concentrations. The samples were presented to panelists in a viewing box. Visual‐threshold determinations were made for each of the nine sample sets using the ascending method of limits (AMLs) and bright illumination (1,192 lux) with each of the three viewing backgrounds: black velvet, white cotton and white taffeta. The thresholds were much more similarly expressed as turbidimeter observations than as either weight or number concentration. With the black‐velvet background, the thresholds ranged from 0.206 to 2.190 nephelometric turbidity units (NTU). With white cotton and white taffeta, they were considerably higher ( P < 0.001), ranging from 1.97 to 41.00 and 2.97 to 34.40 NTU, respectively. This large difference appears to be a matter of contrast – scattered white light is much easier to perceive against a dark background.