In this article, a contamination-irradiation facility designed to measure contamination effects on far-ultraviolet optical surfaces is described. An innovative feature of the facility is the capability of depositing a contaminant, photopolymerizing the contaminant with far-ultraviolet light, and measuring the reflectance of the contaminated sample, allin situ. In addition to describing the facility, we present far-ultraviolet reflectance measurements for a contaminated mirror. ©1998 American Institute of Physics.