Lighting Glossary

Lumens:
A unit of measure used to describe the amount of light, a light source produc emits.

Lux:
A lux is a unit of standard measurement used to determine how much light is emitted at a certain point or distance from the light source.

Lumens/watt:
Lumens per watt is a measure of lighting efficiency. It indicates how much light is emitted per watt of electricity used.

Lifespan:
The average Mean Time Before Failure (MTBF). Lifespan specific to LED refers to how long the LED will last at 100% brightness. After 50,000 hours the LED will still emit light but will decrease 50% in light output over the next 50,000 hrs.

LED:
Light Emitting Diode. A small electronic device that emits light when electricity is passed through it. It is different to traditional lighting technologies that use filaments or gases to produce light.

Incandescent:
Emitting visible light as a result of being heated. Light is produced by an element being heated to produce light by an electric current. Common light bulbs are incandescent.

Fluorescent:
A lamp that produces visible light by conversion of ultraviolet energy from a low-pressure mercury gas arc when electricity is passed between two electrodes.

Solid State Lighting (SSL):
Lights that do not use electrical filaments, plasma, or gas. LEDs, OLED (organic LED), or PLED (polymer LED) are all types of Solid State Lighting.

Voltage:
It is a measurement of the energy contained within an electric field, or an electric circuit, at a given point. Voltage is the difference in electrical charge between two points in a circuit.

IP Rating:
Ingress Protection, is a rating that specifies the strength of the enclosure that houses electronic equipment. Understanding the IP rating system is easy, the first digit measures the degree of protection provided against solid objects, the second number measures the degree of protection provided against liquids. Please look at the table below for ratings:

MR16 Lamp (12v):
MR16s are a type of light fitting. They provide directional light and are well known for their application as downlights.MR16 globe. Below is an example of an MR16 fitting.

GU10 (240v):
GU10 is a type of light fitting. The picture below is an example of an MR16 light fitting:

Bayonet/BC22:
Bayonets or BC22s are a type of light fitting. The picture below is an example of an Bayonet light fitting:

Edison Screw/ES27:
Edison Screw or ES27s are a type of light fitting. The picture below is an example of an Edison screw:

Par Lamp:
PAR stands for Parabolic Aluminized Reflector. They typically use an incandescent filament or a halogen filament tube, now however they are also available in LED alternatives.

Pendant:
Pendants are suitable for either task, general, or spot lighting. They are suspended from the ceiling either from a tube or wire. They optimise space without the need for table lamps.

Accent Lighting:
Directional lighting which highlights an object or attracts attention to a particular area. Examples include lighting artwork, or features. Ambient Lighting:

Beam Angle:
Is a measure of the conical width of light from a light source and is measured in degrees. The smaller the number of degrees the narrower the beam and the larger the degrees the wider the beam, see image below:

Colour Temperature:
A measure of the colour appearance, it helps to describe how warm, or cool a light appears. It is measured in kelvins. The lower the number the, warmer/redder, the light appears. The higher the number the, cooler/bluer, the light appears. See picture below:

Wattage:
It is a standard unit of measure of electrical power. One watt is one ampere of current flowing at one volt. It is a measure of how much electricity a unit uses when on.