Silicon photoelectric diode detector, Φ4mm measuring aperture, CIEL*a*b*C*h* CIEL*a*b* CIEXYZ color space, △E*ab △L*a*b* △E*C*h* color difference formula, LED blue light excitation, 100 pcs standards 20000 pcs samples, 205 x 67 x 80 mm dimension, 450g weight.