4 inch Attenuation Filter


This attenuation filter is used to optimize measurements of highly reflective parts and helps produce good fringe contrast. The filter is positioned between the test part and a standard transmission flat. 

Specifications:  Quality: ≤ ƛ/10 Transmitted wavefront (PVr) Transmittance (4 in. filter) : 20 ± 4% @ 10° angle of incidence @ ƛ=632.8 nm through the pelicle