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Calculating Gloss, Haze, RSpec and DOI from a Goniophotometric profile
For the above example at 20⁰, Novo-Gloss IQ calculates the Gloss value by
summing the gloss /- 0.9⁰ from the specular angle. These tolerances are
specified in ASTM D523/ISO 2813.
The RSpec value is the peak gloss value at the specular angle.
Haze is measured by summing the gloss values between 18-19⁰ and 21-22⁰, the
angles described in ASTM E430.
The DOI value is a function of the slope of each curve, the sharper the gloss
response, the higher the DOI value (100 DOI is a perfect reflecting surface). More
detail of this method can be found in ASTM D5767.
The Novo-Gloss IQ screen displays a low resolution gonio-curve for comparison.
The instrument uses the angular tolerences from ISO 2813 & ASTM D523 to
calculate gloss values at 60⁰. The angular tolerances used at 20⁰ to calculate Haze,
and DOI are also used at this geometry.
Gloss Component
Haze Component
Haze Component
20⁰