ISO DIS 19962

Description / Abstract: This document specifies procedures for determining the spectroscopic forward scattering characteristics of coated and uncoated optical surfaces over a specified wavelength range between 350 nm and 850 nm using a double-beam spectrophotometer with an integrating sphere. This document is also applicable to the forward scattering properties at a single wavelength.

The minimum scattering collection angle is determined by the setup of the double-beam spectrophotometer and the geometry of the integrating sphere, in particular the opening angle of the exit port. In this standard, the collection angle is larger than 2,7 degrees and shall be recorded and considered when comparing the results obtained with different instruments.

Since the measured forward scattering strongly depends on the minimum scattering collection angle, ISO 13696:2002 shall be consulted for smaller than 2,7 degree angle scattering measurement needs. ISO 13696:2002 proposes a scattering measurement setup with minimum scattering collection angle less than 2 degrees.