13 Terms
Contributors in Lighting
Lighting
Spacing criterion
Construction; Lighting
A maximum distance that interior fixtures may be spaced that ensures uniform illumination on the work plane. The luminaire height above the work plane multiplied by the spacing criterion equals the ...
Candlepower
Construction; Lighting
A measure of luminous intensity of a light source in a specific direction, measured in candelas.
Efficacy
Construction; Lighting
A metric used to compare light output to energy consumption. Efficacy is measured in lumens per watt. Efficacy is similar to efficiency, but is expressed in dissimilar units. For example, if a ...
Parabolic luminaire
Construction; Lighting
A popular type of fluorescent fixture that has a louvre composed of aluminium baffles curved in a parabolic shape. The resultant light distribution produced by this shape provides reduced glare, ...
Illuminance
Construction; Lighting
A photometric term that quantifies light incident on a surface or plane. Illuminance is commonly called light level. It is expressed as lumens per square foot (footcandles), or lumens per square ...
PAR lamp
Construction; Lighting
A parabolic aluminized reflector lamp. An incandescent, metal halide, or compact fluorescent lamp used to redirect light from the source using a parabolic reflector. Lamps are available with flood or ...
Photometric report
Construction; Lighting
A photometric report is a set of printed data describing the light distribution, efficiency, and zonal lumen output of a luminaire. This report is generated from laboratory testing.
