Specular reflectance is a non-destr

Specular reflectance is a non-destructive method for surface measurements using a mirror-like
reflection from the shiny (or matt) surface of a sample.
Specular reflectance occurs when the reflected angle of infrared radiation equals the angle of
incidence. The amount of light reflected depends on the angle of incidence, the refractive index,
surface roughness and absorption properties of the sample.
A particularly useful application for specular reflectance is the study of surface coatings, such as
surface treated metals, paints and polymers. Increased pathlengths through thin coatings can be
achieved using grazing angles of incidence (typically 85° angle) and this gives increased
sensitivity. Thicker coatings in the micrometer thickness range can be studied using angles
typically at 30° incidence. The band intensities depend on the type and degree of polarization of
light.
The Specac range of specular reflectance accessories includes both fixed angle and variable
incidence angle accessories. The monolayer/grazing angle accessory can be used for range of
incident angles from 8 to 85° and with both liquid and solid samples.