Total lumen output of a luminaire expressed as a percent of rated bare lamp lumens, as determined by photometric tests.
The ratio of the light emitted by a luminaire to the light emitted by the lamp or lamps within it. Components of a luminaire such as reflectors and diffusers absorb some of the light from the lamp(s). A highly efficient luminaire emits most of the light that the lamp(s) emits.
The ratio of total lumen output of a luminaire and the lumen output of the lamps, expressed as a percentage. For example, if two luminaires use the same lamps, more light will be emitted from the fixture with the higher efficiency.
Total lumen output from luminaire expressed as a ratio of total lamp lumens produced in relation to the luminous output of the luminaire. Commonly referred to as ``fixture lumens" or ``zonal fixture lumens." Luminaire efficiency is expressed as a decimal (real) number generally less than 1.0. For outdoor applications luminaire efficiency is rated in subcategories to describe the downward and upward efficiency. Overall luminaire efficiency considers both downward task light and wasted uplight.
The ratio of lumens emitted by a luminaire to those emitted by the lamp or lamps used.
This is a ratio of light produced by the luminaire as a whole, including whatever shades, baffles and or reflectors that may be fitted, compared to the light produced by the fitted lamp or bulb alone.
