Illuminance (also called illuminance ) is a measure of the amount of light falling on a surface . It is measured in lux (lx) and indicates how many lumens are distributed per square meter on a surface. The higher the illuminance, the brighter a surface appears visually.
The illuminance depends on several factors, such as the intensity of the light source, the distance between the light source and the surface, and the reflectivity of the surface.
Formula for illuminance:
The illuminance is calculated using the following formula:
E=IAE = \frac{I}{A}
Whereby:
- E = Illuminance in lux (lx)
- I = Luminous flux in lumens (lm)
- A = Area in square meters (m²)
Examples of illuminance:
- Dark night : about 0.001 lux
- Office : approximately 300 to 500 lux
- Shop lighting : approximately 500 to 1,000 lux
- Sporting events or stadiums : more than 2,000 lux
Factors affecting illuminance:
- Light source : The type of light source and the intensity of the luminous flux (lumens) emitted.
- Distance : The closer the light source is to the surface, the brighter the illumination. At greater distances, the illuminance decreases.
- Reflection : The type of surface can affect the amount of light reflected. For example, a white wall reflects more light than a dark wall , resulting in higher illuminance on a white surface.
- Light angle : The angle at which the light strikes the surface plays a role in the uniformity of illuminance. Direct light provides a higher concentration, while diffused light spreads over a larger area.
Application of illuminance:
- Work environments : Correct illuminance is important for the productivity and well-being of people working in a given space. For offices, for example , 300-500 lux is often suitable for daily work, while precision work such as in laboratories or workshops requires higher illuminance.
- Shop lighting : For commercial spaces, lighting levels can vary depending on the type of product being displayed. The goal is to make products clearly visible, with lighting between 500 and 1,000 lux .
- Sports facilities : In sports halls or stadiums, high illuminance is essential for television broadcasts and to ensure athletes are clearly visible. This can reach 2,000 lux or more .
Illuminance and visual performance:
- Health and well-being : Inadequate illumination can lead to eye strain and reduced productivity , while too much illumination can cause glare and discomfort. It's important to properly adjust illuminance in different environments to achieve the best possible visual performance.
- Workplace Lighting : The right light intensity can significantly improve productivity and safety in the workplace. Too little lighting can lead to errors , while too much light can cause fatigue or stress .
Summary:
Illuminance is a measure of the amount of light falling on a surface, measured in lux. It is important for visual performance and well-being in various environments. Illuminance is influenced by factors such as the light source, distance, reflection, and angle of the light. Choosing the right illuminance is essential for creating a comfortable and functional space, whether in workplaces, commercial spaces, or sports facilities.