Investigating the correlation between precision and trueness of spectrophotometers in measuring the whiteness index and tint factor of none fluorescence white ceramic

The reflective spectrophotometers are available to users in benchtop and portable models with differentgeometries and designs to measure whiteness and tint attribute of white specimens and color coordinatesof the samples. In these devices, factors like illumination-observation geometry, the type of light sourceand its lifetime, light scattering devices and optical receivers play an effective role in their precision andaccuracy, which will somehow affect the outputs of the devices. In this research, the role of precision andaccuracy of spectrophotometers in measuring the whiteness and tint indices of a BCRA reference whiteceramic tile was investigated. For this purpose, seven spectrophotometers with different models and thesame geometry (di: ۸°) were used. The results showed that not only the operation and maintenance of thedevice directly and potentially plays an important role in the precision and accuracy of the results, butalso spectrophotometers with the same geometry and different models whose precision and accuracy arewithin acceptable tolerances, different results are observed in the whiteness index assessment. So that thedifference of the measured whiteness index compared to the real va lues ranges from ۰.۱۶ to ۳.۲۸ units.

Keywords:

Reflectance spectrophotometer , Precision , Trueness , BCRA Ceramic Standards , Whiteness index