Investigation of the Color Stability of BCRA Ceramic Standards using Univariate Statistical Methods

It is essential to investigate calibrated BCRA ceramic standards reference' color stability to determine the reflectance spectrophotometer's calibration period time. In this research, the color and spectral changes of a set of fourteen BCRA ceramic standards made by Avian Technologies Company were investigated over three years under repeatable conditions. Each ceramic's color changes were evaluated by calculating ∆E*ab and ∆E*00 and then analyzed using univariate statistic metrics such as MCDM and RMS (2S). Similarly, the spectral reflectance factor's variation was evaluated using univariate metrics of the standard deviation of reflectance (∆Rλ,2δ) and RMSR. This study's statistical results showed that the color and spectral reflectance factor of BCRA ceramic standards had no significant changes for three years and established good color stability. The maximum values were obtained for the statistic metric of MCDM (ΔE*ab) within about 0.08 units and the statistic metric of RMSR within about 0.02%. This result can play a significant role in reducing the recalibration costs of these reference ceramics.