Lighting A to Z

GlossaryFull Spectrum Lighting There is no official definition ofthe term “full spectrum” but most agree that it is a source thathas a cool temperature and a high color rendering that mimicsnatural daylight. Philips Colortone 50 or C50 is described as afull spectrum light source.Fuse Safety device to prevent excess current flow.General Lighting Substantially uniform lighting of an area,excluding task lighting.Glare Condition of vision in which there is discomfort or areduction in the ability to see significant objects, or both, due toan unsuitable distribution or amount of light.Group Relamping An economical method to predict bulblife and replace all lamps at one time. Saves time and money.Halogen Lamp Gas-filled lamp containing a tungsten filamentand a proportion of halogen gas. The halogen gas recyclesevaporated particles of tungsten back onto the filament surface.Heat Measured in British Thermal Units (BTUs).Unit BTUs per hour = Watts x 3.413High Intensity Discharge Lamps (HID) HID lampsinclude groups of lamps known as Mercury Vapor, Metal Halide,and High Pressure Sodium.High Pressure Mercury (Vapor) Lamp A long lifelamp, with or without a coating of phosphor, in which an arcflowing through mercury vapor produces a bluish-white light.Deluxe phosphor coated lamps have a higher CRI.High Pressure Sodium Lamps (HPS) A high efficiencyand long life bulb in which an arc flowing through sodium vaporproduces a yellow light.Hot Re-Strike Time In HID lamps, the amount of timeafter a momentary power interruption to return of full light output.Ranges from 1–15 minutes or more, depending on lamp typeand fixture.48 Product Knowledge