The weathering process will have an effect on the specimen’s color. PPT employs sphere spectrophotometers which are the preferred measurement instrument for colors with a textured surface such as textiles, carpets and plastics, as well as shiny and other highly glossy surfaces. A sphere instrument is able to measure the color changes from these surfaces and will return measurements that are very close to what the eye would see when looking at that surface. Sphere instruments are more versatile since they allow for the measurement of a color with or without the impact of its associated surface effects.
Below is an example graph that tracks a specimen’s deCMC throughout a 10,000 hour test.