The floor-mounted external fixed angle specular reflectance accessories allow specular reflectance measurements at fixed angles of 12.5°, 30°, 45°, and 60°. The accessories are particularly useful for studies of film thickness on metallic substrates and measurements of epitaxial film thickness. They do not require a solid sample holder to be installed. If additional accessories, such as a polarizer, are used a slide mounted specular reflectance accessory
may be more suitable.