IESNA TM-15-11

Luminaire Classification System for Outdoor Luminaires

 The technical memorandum, TM-15, defines a classification system for outdoor luminaires that provides information to lighting professionals regarding the lumen distribution within specific solid angles.  The lumens within these solid angles are intended to be one of the metrics used to evaluate luminaire optical distribution including the potential for light pollution and obtrusive light, but not as the only metric that should be evaluated. Light pollution and obtrusive light result not only from the optical characteristics of the luminaires, but also from the application of those luminaires within an outdoor site or roadway. A detailed evaluation of the lighting performance for the outdoor site should be based not only on the luminaire optics, but also on overall system design, including luminaire locations, utilization of light where it is needed, lighting quality, visual tasks, aesthetics, safety requirements, and security issues.

In early 2009 an addendum to TM-15 was published.  It establishes specific maximum zonal lumens for ratings of backlight, uplight and glare. 

Then in mid-2011, the threshold values in the addendum were modified for the U and G components of the ratings.  The FVH and BVH components of the U rating were eliminated so that the Uplight rating is dependent only on uplight.  Then glare thresholds were made more stringent so that the combination UG ratings generally stay the same.