Philips indoor luminairesTechnical data12.56
Glossary of lighting terminology
Luminous efcacy
The quantity of light that a light source emits per unit of electrical
energyconsumed.Noticethattheluminousefcacycanbespecied
for a light source or for a lighting system (lamp and ballast).
Theluminousefcacyofasystemislowerthanthatofthelight
source.
Unit: lm/W
Luminous ux
The total light output emitted by a light source. Also the total light
falling on a surface. The light output of a light source is measured in
lumen.
Unit: lumen
Symbol: f
Luminous intensity
Theluminousuxinagivendirection,e.g.fromaoodlightor
projector.
Unit: candela (cd) = one lumen per steradian
Symbol: I
Lux
The standard unit of illuminance of a surface being lit. One lux equals
one lumen per square meter.
Maintained emergency lighting
Emergency lighting where the lamps are operated from the normal
supply during standard conditions. In an emergency situation the
emergency lamp (usually one lamp in luminaires of two or more
lamps) remains in operation.
Maintained illuminance
Valuebelowwhichtheaverageilluminanceonthespeciedsurfaceis
notallowedtofall.Themaintainedilluminanceisspeciedattheend
of the maintenance cycle, taking into consideration the maintenance
factor.
Itisoneofthemainspecicationelementsforthelightingdesigner.
Inthevariousstandardsthemaintainedilluminanceisspeciedfor
various activities.
Unit: lux
Symbol: E
m
Maintenance factor
Correctionfactorusedinlightingdesigntocompensatefortherate
of lumen depreciation, caused by lamp ageing (lumen depreciation and
lamp failure) and dirt accumulation (luminaire and environment).
It determines the maintenance cycle needed to ensure that illuminance
does not fall below the maintained value.
MASTERColour CDM lamp
Series of metal-halide discharge lamps with excellent color rendering
andawarmorneutralcolorimpression.MASTERColourlamps,also
availableasreectorlamps,areappliedinprojectorsanddownlights
forshopandofceapplications.
Mercury lamp
High-intensitydischargelampforuseinindustryandlargepublic
spaces.Higherqualitylightcharacteristicsareobtainedbyapplying
metal-halide lamps.
Metal-halide lamp
Single- or double-ended discharge lamp for use in industry, public
spaces and shops. Metal-halide lamps combine a natural white color
with a pleasant light and a high luminous intensity.
Movement detection
Sensing of occupancy by movement detection ensures lights are
activatedonlywhenneededandenablesthelightinginaspecicarea
to be controlled.
Non-maintained emergency lighting
Emergency lighting where the emergency lighting lamps come into
operation only when the power supply to normal lighting fails.
OLC
OmnidirectionalLightingControl,aPhilips-patentedseriesof
opticsforTL5andTL-Dlampsofferingoptimallightingefciencyin
combination with excellent glare and luminance control all around the
luminaire.
Optic
A device that changes the direction of a beam of light, usually by
reection,
diffusionorrefractionbyalens.Theopticmayinclude
louvers for reduction of glare.
PL lamp
Single-endedcompactuorescentlampinwhichthedischargetube
is folded into two, four or six limbs. PL lamps are characterized by
unusually high light output for their length. They are applied in compact
luminaires for professional and domestic use. Also available with
integrated ballast.
Power factor
Ratio of the circuit power in watts over the product of the root-mean-
square values of voltage and current. For sinusoidal waveforms, it is
equal to the cosine of the angle of phase difference between voltage
and current. For electronic ballasts the power
factor is 0.95 so that no
additional phase compensation is required.
QL lamp
See Induction lighting.
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