Development of an image-based gloss measurement instrument
The image-based gloss meter was built according to the specifications of the optical layout of a specular gloss meter in a 60° measurement geometry, as described in ASTM D523-14. The photodiode detector was thereby substituted with a CMOS detector. The optical layout of the system was designed and validated by the use of ray tracing software. A series of 16 matte to high-gloss test samples, with nominal gloss values ranging between 3 and 90 gloss units, was used to compare specular gloss measurements obtained with the developed instrument and a commercial specular gloss meter.
More global characterisation of the total gloss impression possible
An average and maximum deviation of only 1.2 and 2.7 gloss units, respectively, was obtained, confirming the suitability of the system to perform standard specular gloss measurements. The potential benefits of the image-based approach were then studied. By way of example, the optical characterisation of orange peel and contrast gloss by the use of the system was discussed, corroborating the fact that the proposed instrument offers important opportunities for a more global characterisation of the total gloss impression.
The study is published in: Journal of Coatings Technology and Research July 2019, Volume 16, Issue 4, pp 913–921.
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