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CA452001EN - March 2015


Glossary of Terms

Activity Area

Area within which a specific activity is carried out.

Anti-Panic (Open) Area Lighting

The part of Emergency Escape Lighting provided to avoid panic and

provide illumination allowing people to reach a place where an escape

route can be identified.

Background Area

Area adjacent to the immediate surrounding area.


British Approvals for Fire Equipment. Single registration scheme for

each product or service within the fire protection industry. SP203-4

is a modular scheme for the design installation commissioning and

maintenance of emergency lighting systems.


The component that controls the operation of a lamp from a specified

low or high voltage AC or DC source (Typically between 12 and 240


Ballast Lumen Factor

The ratio of the light output of the lamp in emergency operation

compared with the light output of the same lamp operated by a

reference ballast at its rated voltage and frequency.


Secondary cells providing the source of power during mains failure.

Battery - Recombination

A battery that is designed to recombine the electrolyte, constructed so

that no provision is made for replacement of electrolyte (sometimes

called sealed).

Battery - Vented

A battery that requires replacement of electrolyte at regular intervals.

Battery Capacity

The discharge capability of a battery, being a product of average current

and time, expressed as Ampere-hours (Ah) over a stated duration.

Note: At fast rates of discharge the full ampere hour capacity of the

battery is not available.

Candela (cd)

The unit of luminous intensity.

Central Battery System

A system in which the batteries for a number of emergency luminaires

are housed in one location. Usually for all the emergency luminaires on

one lighting sub-circuit, but sometimes for all emergency luminaires in

a complete building.

Colour Rendering Index (CRI)

A measure of the degree to which the appearance of a surface colour

under a given light source compares to the same surface under a CIE

reference source. The index has a maximum value of 100.

Colour Temperature (CCT)

All materials emit light when heated (eg, metal glows red through

to white as the temperature increases). The temperature to which

a full radiator (or ‘black body’) would be heated to achieve the same

chromaticity (colour quality) of the light source being considered, defines

the correlated colour temperature of the lamp, quoted in degrees Kelvin.

Combined Emergency Luminaire

A luminaire containing two or more lamps, at least one of which is

energised from the emergency supply and the remainder from the

normal supply (If the emergency lamp is only illuminated in a mains

failure condition this luminaire is regarded for fire authority approval as


Design Voltage

The voltage declared by the manufacturer to which all the ballast

characteristics are related.

Disability Glare

Glare produced directly or by reflection, that obscures or impairs vision

of an object, but does not necessarily cause any discomfort.

Discomfort Glare

Glare which causes visual discomfort.

Downward Light Output Ratio (DLOR)

The ratio of luminaire light output below the horizontal, compared with

total lamp light output.

Emergency Lighting

The lighting provided for use when the supply to the normal mains

lighting installation fails.

Escape Route Lighting

Lighting provided to ensure that the means of escape can be effectively

identified and safely used when a location is occupied.

Emergency Exit

The way out of a building, which is intended to be used at any time

whilst the premises are occupied.

Final Exit

The terminal point of an escape route, beyond which point persons are

no longer in danger from fire or any other hazard requiring evacuation of

the building.


The discomfort or disability that occurs when there is an excessive

change of luminance in the field of vision.

High Risk Task Area Lighting

Emergency lighting provided to ensure the safety of people involved in

a potentially dangerous process or situation and to enable proper shut

down procedures for the safety of the operator and other occupants of

the premises.

Housing 850°C Test

Mandatory test for emergency luminaires used on escape routes, to

establish that materials do not burn at given temperature.

Self-extinguishing grades of plastic must be used, or alternatively glass

and/or steel.

ICEL 1001 Registration

The industry standard for the approval of photometric performance and

claimed data of emergency lighting equipment, which is tested by the

British Standards Institute.

Impact Protection

Number classification of the degree of protection a luminaire provides

against mechanical impact.

Immediate Surrounding Area

Band surrounding the task area within the field of visual field.

Ingress Protection (IP) Number

Number Classification of the degree of protection a luminaire provides

against the entry of solid foreign bodies and moisture.

Isolux Diagram

Diagram showing contours of equal illuminance.