Reflectance Arrangement
Spherical measurement systems provide a highly uniform illumination for textile samples by reflecting light off a coated internal chamber. The d/8 geometry uses diffuse lighting to hit the fabric from all angles while the sensor views the surface at an 8 degree offset. This setup is particularly effective for measuring the color of textured or irregular materials.
Specular Component
Modern instruments allow the operator to include or exclude the gloss reflection from the final data. Using d/8 geometry in specular included mode provides the total color of the material regardless of its surface finish. This is useful for comparing the dye strength of a fleece fabric against a smooth jersey.
Sample Mounting
Placement of the specimen against the measurement port must be firm and consistent to avoid light leakage. When using d/8 geometry, the large area of view helps to average out the variations in the knit or weave pattern. The diffuse nature of the light prevents the harsh shadows that can occur in directional systems.
Most mills prefer this geometry for bulk production monitoring because it is less sensitive to how the operator orients the fabric.
Measurement Reliability
Results from a spherical instrument are generally very repeatable across different laboratory locations. The sphere acts as a light integrator that minimizes the influence of minor surface flaws.
