Diffuse reflectance scales at NPL

The National Physical Laboratory currently disseminates United Kingdom diffuse reflectance scales from 320 nm to 56 μm. The scale for hemispherical reflectance from 360 nm to 830 nm was previously traceable to the National Research Council of Canada and the Physikalisch-Technische Bundesanstalt, and its extension to 56 μm has relied partly on data published by Morren et al. (1972). Measurements of 0°/45° radiance factor from 360 nm to 830 nm were traceable to the Physikalisch-Technische Bundesanstalt. The National Physical Laboratory now realizes all United Kingdom diffuse reflectance scales independently as described here.