illumination unit
Noun: A unit of measurement for the amount of light (illumination) falling on a surface. It quantifies luminous flux per unit area.
The term "illumination unit" is a technical term used in physics, engineering, and lighting design to specify and compare light levels. * The required illumination unit for detailed office work is higher than that for a corridor. * Sensors measure the ambient light and report the value in a standard illumination unit. * When designing the stadium lighting, engineers calculated the necessary illumination units for television broadcasts.
- In scientific contexts: The term is often used when discussing photometry, the science of measuring visible light as perceived by the human eye.
- In regulations and standards: Building codes and workplace safety guidelines frequently specify minimum required levels in specific illumination units.
- Lux (lx): The SI derived unit of illuminance, equal to one lumen per square metre. This is the most common modern illumination unit.
- Foot-candle (fc): A non-metric unit of illuminance, equal to one lumen per square foot. It is still used in some regions, particularly the United States.
- Illuminance: The physical quantity that illumination units measure; the total luminous flux incident on a surface per unit area.
- Luminous flux: The measure of the perceived power of light, expressed in lumens (lm), which is a component in defining illumination units.
- Unit of illuminance
- Light measurement unit
The term "illumination unit" is highly specific and technical. It does not commonly refer to: * A physical device or lamp that provides light (that would be a "lighting unit" or "luminaire"). * The act or process of illuminating.
- a measure of illumination