Analysis of spectrophotometer specular performance using goniometric information
Abstract
The 1986 Cifi document 15.2, Colorimetry, was necessarily broad in specifying the use of the gloss trap or specular port in
integrating sphere measurements. This has led to a variety of spectrophotometer configurations that adhere to the Cifi
recommendation. To help users of these devices determine the performance of their instruments with respect to specular
excluded measurements, a procedure has been demonstrated to quantify the effective specular port width of an integrating
sphere device. The proposed procedure has been tested on four spectrophotometers, three of which use conventional specular
ports of varying sizes. The specular ports of these three devices can be physically measured, however the fourth device uses
and alternative method for the specular excluded measurement, and the diameter of its specular port cannot simply be
measured. The procedure allows for a relative comparison of conventional devices and those using an alternative method.