| •The main material of inner paint layer is pure barium sulphate and it is difficult to become yellow for a long time. Meet requirements of CIE pub.NO.84(1989).Fine diffuse reflection reflectance p≈0.8.Variation of ρ(λ)<1.5%(380nm-780nm);•Multi interface on the sphere, testing of photometers and colorimeters at the same time;•DIA: φ0.3m、φ0.5m、φ1.0m、φ1.5m、φ2.0m. | 
