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LRC News

March 2009
Mesopic Characterization of Nighttime Lighting Described in New ASSIST Guidelines

Outdoor lighting supports many types of nighttime activities, from transportation to recreation to business, and has become a quickly growing market for LED lighting systems. Much attention has been paid to increasing the luminous efficacy of outdoor lighting systems, and particularly to LED systems looking to replace traditional light sources used in this application. Yet, traditional means of finding the most efficacious light source for outdoor applications are not always appropriate.

The Alliance for Solid-State Illumination Systems and Technologies (ASSIST) has published a new volume in its ASSIST recommends series, "Outdoor Lighting: Visual Efficacy." The volume describes the unified system of photometry, developed through previous research by the LRC, which can better characterize the photometric performance of light sources under nighttime applications. This system can help lighting specifiers and decision-makers to better optimize, and thereby reduce the cost, of operating lighting systems at night, including LED lighting systems.

The volume is available for free download from the ASSIST Web site.

About the Lighting Research Center

The Lighting Research Center (LRC) is part of Rensselaer Polytechnic Institute of Troy, N.Y., and is the leading university-based research center devoted to lighting. The LRC offers the world's premier graduate education in lighting, including one- and two-year master's programs and a Ph.D. program. Since 1988 the LRC has built an international reputation as a reliable source for objective information about lighting technologies, applications, and products. The LRC also provides training programs for government agencies, utilities, contractors, lighting designers, and other lighting professionals. Visit

Contact:lrcnewsletter@rpi.eduPhotos & Graphics:Dennis Guyon
Editor:Mary CimoWeb Production:Joann Coffey
Contributing Writers:Jennifer Taylor, Mary Cimo
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