... report diffuse reflectance factor Rx, Ry, Rz IntroductionZB-A color difference meter is the professional instrument to test the object of the ... λd, excited purity Pe, color difference ΔE*ab, lightness difference ΔL*, chromaticity difference ΔC*ab, hue difference ΔH*ab, Hunter system L, ... chromaticity coordinate s≤0.0010,.R457 s≤0.105.Sampler size: Diameter of the testing plane should be larger than ...