Microspectrophotometry of Wood Grain and Color

Authors

  • Howard James Swatland University of Guelph, Canada

DOI:

https://doi.org/10.24203/ajet.v9i1.6519

Keywords:

Microspectrophotometry, Colorimetry, Wood color, Wood grain

Abstract

A reflecting microscope spectrophotometer was used for the colorimetry of wood using CIE (Commission Internationale de l’Éclairage) chromaticity coordinates.  A microscope scanning stage and scanning with optical fibers were used to detect grain patterns. Ten exotic woods with a fine grain structure were tested because they are highly valued in the manufacture of musical instruments and furniture, and they had a wide range in color and grain structure. With lateral illumination (45°) of samples and a large measuring aperture, the results were comparable to those that might be obtained with a commercial colorimeter detecting diffuse Lambertian reflectance. With vertical illumination and coaxial photometry in a microscope, Fresnel reflectance was dominant. The best predictor of CIE x with lateral illumination was reflectance at 400 nm (r = - 0.916, P < 0.0005) and the relationship persisted with vertical illumination (r = -0.67, P < 0.025).   Scanning across woods at 520 nm with a microscope scanning stage, there were relationships of CIE x with scanning peak height (r = 0.75 P < 0.01).   In scanning across 6 cm of wood with optical fibers, there was a relationship of the number of reflectance peaks (from wood grain between dark lines) with peak width (r = - 0.89, P < 0.0005). Woods with a fine grain had numerous small peaks while woods with a coarse grain had a few wide peaks. Thus, there is a connection between the color and grain pattern of wood.

Author Biography

  • Howard James Swatland, University of Guelph, Canada

    University Emeritus Professor

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Published

2021-02-25

How to Cite

Microspectrophotometry of Wood Grain and Color. (2021). Asian Journal of Engineering and Technology, 9(1). https://doi.org/10.24203/ajet.v9i1.6519