The Rhopoint ID Transmittance (Visible transmittance) is a much more relevant measurement than Traditional Hazemeter Transmittance (Total Transmittance)

Rhopoint Transmittance (TID) quantifies the amount of light passing through the material and reaching the camera/eye of the observer. This measurement describes the brightness/luminosity of the viewed object and is correlated to how one perceives the quality of the material.

Total Transmittance from a traditional instrument quantifies absorption within the material and is not related to its appearance to an observer.