Glossary

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
WP:
Working Plane: The surface or level on which light is measured
Maintenance Factor:
The method of calculating light loss after installation
RSMF:
Room Surface Maintenance Factor Calculates the loss of light from reflective surfaces such as floors and walls
LMF:
Luminance Maintenance Factor Considers the loss of light from a luminaire after a given usage due to dirt disposition
LLMF:
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
Maintained:
A luminaire incorporating one or more lamps which function from both mains and emergency supply
Combined:
A luminaire incorporating two or more lamps, one of which only functions from the emergency supply, the remainder from the mains
Sustained:
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
Self-Test:
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.

Contact Us

Credits & Legal