Efficiency (LOR)
Optical output; percentage ratio between the output luminous flux of the light fitting
and the flux emitted by the light source.
Electrical connector
An electrical connector such as an electrical component, or an area of a printed circuit
board, whose function is to electrically connect two or more electrical components
exclusively by means of operations of a mechanical type (therefore without requiring
electric welding).
Electrified track
Power supply system with voltage or low tension. Electrical conductors are located
inside the track.
Electromagnetic wave
Electromagnetic energy carrier in single packs or ‘quantums’ of energy, with a defined
energy value. It moves in a straight line at approximate 300,000 Km/s. It has associated
magnetic and electrical fields varying in time following a sine law.
Elliptical reflector
Ellipsoidal mirror (rotational or not) that, with a light source on the first focus, can
replicate its image on the second focus (if rotational ellipsoid) or on a specific area of
the optical axis (if non rotational ellipsoid).
Emission angle
In a projector, or in a rotosymmetrical / X-Y type device, it is double the angle made
by the direction of the axial luminous intensity and the direction where intensity is ½
of the axial.
Emergency lighting
Lighting intended for use when a general lighting system fails due to a power failure.
EN 12464
Standard that defines lighting technology features such as average illumination, uni-
formity, colour rendering and UGR for interiors. This standard also defines the maximum
luminance of a device to be used in environments where there are video terminals.
F
Field of Vision
Of the eye or eyes. Angular width of the space in which an object can be when the
observer looks at an object directly in front of him. The field can be monocular or
binocular.
