Accurate Color Measurement

In this thesis studies on accurate surface color measurements are considered. Errors in a spectrophotometric measurements are discussed and correction methods introduced. The wavelength interval in a tristimulus integration is considered next. The ASTM weighting functions are tested with a large data set of non fluorescent colors and shown to be useless. The thermochromic effect is also discussed in detail and measured. This thesis shows how thermochromism is based on physical processes. Simple formulas are derived, and shown to explain the experimental data. In conclusion, this thesis shows how commercial instruments should be calibrated for precision color measurements, if one aims at achieving the highest level for measuring accuracy.