... reflectance factor Rx, Ry, Rz IntroductionZB-A color difference meter is the professional instrument to test the ... chromaticity coordinate x10, y10, z10;lightness L*;chrominance a*, b*;chromaticity C*ab;hue angle h*ab ... standard colorimetric system and CIE 1976 (L*a*b) color space and color difference formula.3 ... the imported Thermal Printer , no need to use ink and colored tape, no noise and fast ...