Transmittance : 투과도
투과율은 물체를 직접 통과하지 않고 내부 산란이나 다중 반사를 통해 전달되는 복사도 고려합니다. 반구형 투과율(hemispherical transmittance)은 물체가 빛을 산란시킬 때 중요한 전체 투과 복사 플럭스를 고려합니다. 반면 지향성 투과율(directional transmittance)은 투과복사와 입사복사의 비율로 정의되며 관측 각도의 함수가 됩니다.
The term transmittance refers to the ratio between the transmitted and incident radiant power for a specific object. When looking at flat, unstructured surfaces, the term has the same meaning as transmissivity. However, the term transmittance is more general.
Transmittance also takes into account radiation that does not pass through the object directly but through internal scattering or multiple reflections. The hemispherical transmittance considers the total transmitted radiant flux, which is important when objects cause light scattering. Directional transmittance, on the other hand, is defined as the ratio of transmitted to incident radiant power, making it a function of the angle of observation.