The digitalization of metrology poses a challenge to all members of the metrology community. We propose an approach for digital calibration certificates (DCCs) based on a PDF/A-3 solution that could be a stepping-stone towards the digitalization of metrological services. We present multiple applications of this approach by fulfilling discussed minimum requirements and satisfying needs from both customers and laboratories.

Large effect pigments, widely used in various fields of industrial applications, produce characteristic visual textures known as sparkle and graininess, which need to be quantified by objective or subjective methods. The development of preliminary measurement scales for sparkle and graininess, whose recommendation is now under discussion in the International Commission on Illumination (CIE), is described in this article. These scales are absolute, linear and traceable to standards of optical radiation metrology. The main purpose of this article is to justify the convenience of adopting these preliminary measurements scales, showing clear evidence that they correlate well with subjective evaluations. Before standardization, these scales need to be validated with more experimental data, including different specimens and experimental systems from other research groups.

Large-effect pigments, due to their strongly specular reflectance, produce a special visual texture known as sparkle. The use of these pigments in many industries (automotive, cosmetic, paper, architecture...) makes the control of this visual texture necessary. Sparkle measurands have been defined in this article, so that traceability of sparkle measurements can be provided by national metrology institutes or designated institutes. Some of them (Physikalisch-Technische Bundesanstalt, Eidgenössisches Institut für Metrologie, Cesky Metrologicky Institut and Consejo Superior de Investigaciones Científicas) have tested their existing measurement capabilities for the defined sparkle measurands, and their results are presented and thoroughly compared. Two possible sources of systematic error have been identified: inadequate illumination and collection solid angles, and an inadequate size of the virtual aperture used to assess the luminous flux reflected by the effect pigments. Finally, it has been shown that the measures correlate excellently with the sparkle visual data. The results shown in this research support the sparkle measurands defined here as adequate quantities for defining the standard measurement scale of sparkle claimed by industry.

Diffuse reflectance measurements are usually performed using a single photodetector.However graininess measurements require also spatial resolution, thus the measurements are performed using a radiometric camera attached to the integrating sphere in the measurement geometry d:0°.When performing such measurements on glossy samples, an interesting phenomenon was observed; a dark area corresponding to the specular excluded area.METAS and PTB have performed a systematic study on a set of samples having different values of gloss, lightness, and colour, using two different measurement setups.It was found that the size of the dark area could be calculated using geometric relations of the measurement setup.Furthermore, the luminance factor of the dark area, compared to its surround can be correlated with the gloss value of the sample; the glossier the sample, the greater the difference between the dark area and its surround.