Technical Glossary Transmittance (Total Light Transmittance)

[Transmittance (Total Light Transmittance)]

Total Light Transmittance is defined as the CIE Standard Illuminant D65 that passes through material when light from said illuminant is shined onto it.
The illuminant D65 recreates standard illumination conditions in an outdoor environment. The measuring methods are standardized in ISO 13468-1 and JIS K 7361-1.
100% transmittance is only possible when no test sample is present, and the closer the transmittance is to 100%, the more transparent the test sample is.