General Terms

Lumen Output: (lm)
The SI unit of luminous flux.
A quantity of light emitted by a source i.e.: a lamp
Lumens per Watt: (lm/w)
How many lumens are produced for one watt of power. The ratio of light emitted by a lamp to the power consumed by the lamp
Illuminance: E Unit: (lux)
The luminous flux at a point on a surface.
The physical measure of brightness
CRI: Color Rendering Index
The effect of a light source on the color appearance of objects
CCT: Correlated Color Temp
Color temperature is a simplified way to characterize the spectral properties of a light source. SI unit for color temperature is Kelvin (K).
Lux: (lx)
The unit of illuminance, equal to one lumen per square metre
Working Plane: The surface or level on which light is measured
Maintenance Factor:
The method of calculating light loss after installation
Room Surface Maintenance Factor Calculates the loss of light from reflective surfaces such as floors and walls
Luminance Maintenance Factor Considers the loss of light from a luminaire after a given usage due to dirt disposition
Lamp Lumen Maintenance Factor The proportion of the initial light output of a lamp produced after a given time

Emergency Lighting

Non Maintained:
A luminaire incorporating one or more lamps which function from the emergency supply only upon a full mains failure
A luminaire incorporating one or more lamps which function from both mains and emergency supply
A luminaire incorporating two or more lamps, one of which only functions from the emergency supply, the remainder from the mains
A luminaire containing two or more lamps, at least one of which is energized from the emergency supply and the remainder from the normal supply
A Self–Test luminaire carries out regular dependable automatic testing of the battery, charger and lamp(s), if any faults there is visual/wireless fault identification.