Definitions for "Lamp Lumen Depreciation"
Lumen depreciation is a term that describes the normal attrition of light. Essentially, the longer a lamp operates, the less light it delivers. Different light sources have different rates of depreciation.
the reduction in lamp light output that progressively occurs during lamp life.
The decrease in lumen output that occurs as a lamp is operated, until failure. Also referred to as lamp lumen depreciation (LLD).