18 Terms
Contributors in Lighting
Lighting
halogen
Construction; Lighting
A gas-filled tungsten filament incandescent lamp with a lamp envelope made of quartz to withstand the high temperature. This lamp contains some halogens (namely iodine, chlorine, bromine, and ...
room cavity ratio (RCR)
Construction; Lighting
A ratio of room dimensions used to quantify how light will interact with room surfaces. A factor used in illuminance calculations.
nadir
Construction; Lighting
A reference direction directly below a luminaire, or "straight down" (0 degree angle).
low-voltage switch
Construction; Lighting
A relay (magnetically-operated switch) that allows local and remote control of lights, including centralized time clock or computer control.
twin-tube
Construction; Lighting
A small fluorescent lamp that is often used as an alternative to incandescent lighting. The lamp life is about 10 times longer than incandescent lamps and is 3-4 times more efficacious.
lens
Construction; Lighting
Transparent or translucent medium that alters the directional characteristics of light passing through it. Usually made of glass or acrylic.
trigger start
Construction; Lighting
Type of ballast commonly used with 15-watt and 20-watt straight fluorescent lamps.
