Patent ID: 7872753

Claim:
A method for establishing light reflection properties of a specific surface, by selecting from among a number of tables of reduced luminance coefficients (r-tables) measured for comparison surfaces, a table suited to characterise said specific surface, said method comprising: a. measuring, for samples of a plurality of comparison surfaces, the parameters for their r-tables, using a measuring apparatus in accordance with CIE standard recommendations; b. measuring, for those same samples of a plurality of comparison surfaces, a selected light reflection parameter for a selected combination of angles (γ) of incident light and angles (90°−(α)) and (β) of reflected light, using a portable measuring apparatus; c. measuring in situ, on multiple measuring points of said specific surface, said selected light reflection parameter for said selected combination of angles (γ) of incident light and angles (90°−(α)) and (β) of reflected light, using said portable apparatus; d. comparing, by mathematical and/or graphical analysis, the angular distribution of said selected parameter for the specific surface with the angular distribution of said selected parameter for said comparison surfaces, in order to select the comparison surface showing the best distribution fit, optionally taking into account a rescaling factor on luminance coefficient QO; and, e. assigning to said specific surface the light reflection properties of the r-table corresponding to said selected comparison surface, with use of said optional rescaling factor.