How To Measure Absolute Reflectance with the Variable Angle Specular Reflectance Attachment
The variable angle specular reflectance, or VASR, attachment is available on several Shimadzu UV-Vis spectrophotometers – UV-2600i, UV-3600i Plus and the SolidSpec-3700i. The spectral ranges of VASR attachments vary with each model. For example, the one on the SolidSpec-3700i can measure from 250 nm up to 2500 nm when the angle of incidence is less than 12 degrees. The angle of incidence may vary from 5 to 70 degrees. A VASR attachment is good for measuring both transmittance and reflectance at variable incidence angles. In this demo, I will measure the absolute reflectance of a mirror.








