Seeing Versus Saving Recommendations for Calculating Research Use-Lighting for Library Special Collections

The research presented in this paper describes the measurement of light and ultraviolet energy within a special collections facility, with the goal of evaluating whether levels recommended for museums and archival collections are being exceeded during research usage. An Elsec 764 hand-held light meter was used to record the light intensity falling on collection material held within and without V-shaped book mounts and with sequential lights turned on, as occurs in collections' use. The authors developed a simple algebraic formula to calculate cumulative doses of light and incident ultraviolet radiation to determine how many hours collection material could be accessed and illuminated before damage could be expected. The authors calculated the maximum cumulative doses possible based on numbers of access hours and compared these to recommended doses for sensitive media as a monitoring strategy for the long-term preservation of light sensitive special collection materials. The results from this study suggest that the light levels evaluated are not in excess of recommended values and that the use of book mounts reduces the amount of light falling on collection material. Monitoring actions are recommended for institutions wishing to replicate the study.