Glossary

Light fixture

A device designed to direct, filter or diffuse the light coming from one or more sources. A light fixture usually includes a housing, a holder for the light source, and optical and electrical components.

Examples:

• Desk lamps or table lamps – intended for localised lighting.

• Spotlights and recessed downlights – mounted in ceilings or walls.

• Chandeliers, ceiling lights, wall lights – mounted on the ceiling or on the wall.

• Outdoor and indoor floodlights.

• Urban lighting solutions – lamp posts and fixtures for public lighting.

• Architectural lighting – highlights exterior design elements.

Illuminance

It represents the amount of luminous flux that reaches a given surface. It is measured in lux (lx), where 1 lx is equal to the illuminance of a 1 m² surface receiving a flux of 1 lumen.

Examples:

• 1 lx – light of the full moon

• 10 lx – public street lighting

• 100-1000 lx – offices and workspaces

• 10,000 lx – operating theatres

• 100,000 lx – sunlight at noon

Colour temperature

It indicates the shade of the light emitted by a source and is measured in Kelvin (K). Warm light has lower values (2700K-3500K), while cool light has higher values (5000K-6500K).

Luminous flux

The total amount of visible light emitted by a light source, measured in lumens (lm).

IP protection rating

A two-digit code that indicates the level of protection of a device against dust and water:

• The first digit (0-6) – protection against solid particles.

• The second digit (0-8) – protection against water.

Examples:

• IP20 – minimal protection, indoor use.

• IP44 – protection against water splashes, suitable for bathrooms.

• IP65 – resistant to water jets, usable outdoors.

• IP68 – completely watertight, submersible.

Light pollution

An excess of artificial light that can affect ecosystems, disturb sleep, hide the starry sky and contribute to unnecessary energy consumption.

Indirect lighting

A type of lighting in which the luminous flux is reflected by surfaces (ceiling, walls), so that the directly emitted light is below 10% of the total.

Colour rendering index (CRI - Ra)

A parameter that indicates how faithfully a light source reproduces the colours of objects, compared with natural light. Values range from 0 to 100, where 100 indicates perfect colour rendering.

Light intensity regulator (Dimmer)

A device that allows the light intensity to be adjusted by changing the supply voltage of the light source.