Element of luminaire photometric report typically presented in the manufacturer catalog sheet for the product. The table lists the luminaire's light output in lumens for specific zones and then summarizes for all light emitted down (0-90°), up (90-180°) and total (0-180°). These values are in turn used to calculate luminaire efficiency, the percentage of lamp light output that exits the luminaire relative to the total lamp lumens emitted by its light source.
Original Chapter Source: Luminaires
Provided By: Craig DiLouie