Patent ID: 6906857

Claim:
An accelerated weathering device suitable for testing product samples, the accelerated weathering device comprising: a weathering fixture adapted to hold the product sample; and an illuminator disposed approximate the weathering fixture, the illuminator adapted to provide illumination to the product sample; wherein the illuminator includes a light source having spectral characteristics in at least the range of 200 nm to 400 nm; and an optical filter disposed proximate the light source the optical filter comprising: a lead glass filter of visible light absorbing components and having a thickness selected such that illumination passed through the lead glass has a first ratio of a first total irradiance for wavelengths shorter than 290 nm to a second total irradiance for wavelengths between 300 nm to 400 nm, wherein the first ratio is less than 2.0×10 −6 ; and a second ratio of an irradiance at 310nm to the second total irradiance, wherein the second ratio is at least 1.2×10 −3 .