What are the testing standards for paper Colorimeters?

ISO 2469 "Paper, board and pulp - Determination of diffuse reflectance factor"

ISO 2470 "Paper and board - Determination of whiteness (diffusion/perpendicular method)"

ISO 2471 "Paper and board - Determination of opacity (paper backing) --- Diffuse reflectance method"

ISO 9416 "Determination of paper light scattering and light absorption coefficient (Kubelka-Munk)"

GB/T 7973 "Determination of Diffuse Reflectance Factor of Paper, Cardboard and Pulp (Diffuse/Perpendicular Method)"

GB/T 7974 "Determination of Brightness (Whiteness) of Paper, Board and Pulp (Diffuse/Perpendicular Method)"

GB/T 2679 "Determination of Paper Transparency"

GB/T 1543 "Paper and board - Determination of opacity (paper backing) (diffuse reflectance method)"

GB/T 10339 "Determination of Light Scattering and Light Absorption Coefficients of Paper, Board and Pulp"

GB/T 12911 "Determination of Ink Absorption of Paper and Board"

GB/T 2913 "Test method for whiteness of plastics"

GB/T 13025.2 "General test method for salt industry, determination of whiteness"

GB/T 5950 "Measurement method for whiteness of building materials and non-metallic mineral products"

GB/T 8424.2 "Instrumental evaluation method for relative whiteness of textile color fastness test"

GB/T 9338 "Measurement method for relative whiteness of fluorescent whitening agent"

GB/T 9984.5 "Determination of Whiteness by Industrial Sodium Tripolyphosphate Test Method"

GB/T 13173.14 "Determination of Whiteness of Powdered Detergents by Test Methods for Surfactant Detergents"

GB/T 13835.7 "Test method for whiteness of rabbit hair fiber"

GB/T 22427.6 "Determination of Starch Whiteness"

QB/T 1503 "Determination of Whiteness of Ceramics for Daily Use"

FZ-T50013 "Cellulose Chemical Fiber Whiteness Test Method Blue Light Diffuse Reflection Factor Method"