Patent ID: 7652755

Claim:
A color measurement and color grading apparatus comprising: a measuring means for measuring the spectral reflectance of a sample; a dual integrating sphere measurement arrangement that is configured to house a sample, provide diffused uniform illumination on the sample, collect reflectance light from the sample, and transmit the reflectance light to the measuring means; a computer that is configured to calculate measurement parameters, control the measuring means; calculate colorimetric data, determine average color grade, and determine true color grade wherein said dual integrating sphere measurement arrangement is comprised of: a sample integrating sphere that is configured to provide a diffuse white measuring environment for a sample, which sample integrating sphere has a bottom, an internal area, and an open area; a measurement integrating sphere with at least one fiber optic sample port, a light port, an internal area, an open area, and a top; a sample platform connecting the measurement integrating sphere to the sample integrating sphere, which sample platform has an upper surface, a bottom surface, and a middle, and which sample platform contains a round hole called a measurement window; a measurement window filter, set on the sample platform, which measurement window filter is configured to accommodate a sample; a lens system attached to the measurement integrating sphere and configured to receive reflectance light from the sample; a light trap configured to eliminate specular reflection, and attached to the measurement integrating sphere; a light source configured to provide spectral power radiation in the visible wavelength range, attached to the measurement integrating sphere; and a baffle attached to the measurement integrating sphere and configured to block the light from the light source directly to the sample and said lens system.