Ignitor... UNEQUAL LUMENS

摘要

In the light of recent research, Richard Forster argues for new standards of HID lamp and ballast production that would enable easier retro-fit solutions for different visual needs. The interesting paper by Dr Ian Lewin (Lighting Journal, Vol 64/No 2, March/April) provides evidence that comparing the lumen output of different types of lamp may no longer be a dependable measure of visual performance, particularly under mesopic conditions. The reliability of lumen output as a measure of visual efficiency may not be critical for many interior lighting situations, where lighting levels are within the photopic region, for which the CIE Ⅴ(λ) curve for a standard observer was established. However, it is more important for exterior roadway lighting, security floodlighting and escape route lighting, with levels in the mesopic region, where visual performance has implications for safety, risk of injury and so on.