Introduction:
ISO 5-2:2009 The international standard referred to the geometric requirements for transmittance density. Transmittance density, which is frequently expressed in terms of light transmission through a substance or optical apparatus, is defined as the logarithm of the reciprocal of the luminous transmittance of an optical system.
This standard probably specifies or offers instructions for measuring and reporting transmittance density, along with the geometric parameters that determine the validity and accuracy of these measurements. It might involve factors that may influence transmittance density readings, such as the measuring area’s size and shape, the angle at which light incidence occurs, and other elements.