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.