We are able to measure material yellowness index and whiteness index according to ASTM E313-20. The measurement part is the same as our usual material color measurement.
The spectral reflectance data in the 380 nm – 780 nm range are used in the calculation. Our in-house software Color@OTM has been upgraded for automated calculation.
As the spectral range is included in the daylight reflectance test and solar reflectance index (SRI) test, it is possible to re-use the spectral data collected in the two tests for yellowness index and whiteness index calculation, without re-testing.