This project addressed the needs of the standardisation group CEN/TC 89/WG 12 for improvement of the standard EN 16012. The overall objective was to enable end-users to perform SI traceable measurements of total hemispherical emissivity on low emissivity foils used in "reflective insulation" products with an uncertainty below 0.03. The targeted industry focuses on the production of thermal insulation materials.
Metrology Research Institute contributed to this task by developing a method for modelling surface shape of non-flat samples that could be used for more reliable calibration of commercial instruments and hence decrease uncertainty of measured insulators’ emissivity. The method was based on the macrofacets’ distribution model, which parameters can be extracted from the study of the reflection distribution of reflective insulators. A complex sample surfaces was modelled (Figure 1) and validated by optical Monte-Carlo simulations.
MC simulation results showed good agreement of modelled reflectance with the one that was physically measured from foil. However, modelled reference samples’ surface shapes are yet to be tested in real measurements facilities. For this reason real samples (Figure 2) were produced in Fraunhofer Institute and its performance is currently tested at PTB and LNE.
Contact person: Farshid Manoocheri and Dmitri Lanevski
More information about developed macrofacets’ distribution model:
Dmitri Lanevski, Farshid Manoocheri, Anna Vaskuri, Jacques Hameury, Robert Kersting, Christian Monte, Albert Adibekyan, Elena Kononogova and Erkki Ikonen, "Determining the shape of reflectance reference samples for curved surface reflectors", Meas. Sci. Technol. 31 054010, 2020, https://doi.org/10.1088/1361-6501/ab68bf
More information about the project can be found at the project website: