Design and characterization of a versatile reference instrument for rapid, reproducible specular gloss measurements

A reference goniospectrophotometer has been developed at the National Research Council of Canada (NRC) for providing high-accuracy traceable measurements of specular gloss at several standard geometries, including 75 degrees for paper samples, haze and absence-of-bloom gloss, and color appearance of gonio-apparent materials. This is to the authors' knowledge the first reported reference instrument that has this level of versatility for rapidly characterizing the total visual appearance properties of a wide variety of materials and applications. This instrument also replaces the NRC glossmeter that has been providing primary level specular gloss measurements in accordance with International Organization for Standardization and American Society for Testing and Materials standards for measurements of paint and ceramic materials at geometries of 20 degrees, 60 degrees, and 85 degrees. The new instrument has been fully characterized for sources of error and compared with the NRC glossmeter. Its measurement reproducibility of 0.02 gloss unit is a factor-of-5 improvement, and its overall estimated expanded (k = 2) uncertainty is 0.3 gloss unit at all three standard geometries.