Wide angle scattering, at an angle greater than 2.5° from normal (ASTM D1003) causes haze due to a loss of transmissive contrast.
Haze can be the result of environmental damage from weathering or surface abrasion. The difference in haze percentage between an exposed/abraded and unexposed/unabraded specimens quantifies this damage.
Smithers Pira is able to measure haze by the spectrophotometer method, ASTM D1003, Procedure B.
A Perkin Elmer Lambda 650 UV/Vis spectrophotometer having a hemispherical optical measuring system, with a 150mm integrating sphere is used.