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Reflection and Transmission

Working Group 4.51

Diffuse reflection

The methods applied for diffuse reflection at PTB can be basically distinguished between hemispherical/directional and angle resolved goniometric methods. The former applies an integrating sphere in which the sample is diffusely illuminated by the surrounding half sphere and the reflected power is measured in a certain direction.

Opens internal link in current windowSpectral radiance factor β(λ) in hemispherical-directed geometries (sphere geometries)

In goniometric measurements the illumination as well as the detection is performed in defined directions. In the set-up almost any geometry can be realized.

Opens internal link in current windowGonioreflectometry, bidirectional reflectance distribution function (BRDF)

  • Colour classification of white sugar
  • Characterisation of the visual appearance of diffuse surfaces in multi geometry configurations