What is Illumination?
Illumination is denoted by ‘E’. Illumination is defined as the luminous flux obtained by the surface per unit area. Luminous flux is the total amount of light energy emitted per second from a luminous body. Illumination varies from light, however these terms are used more or less the same. Light originates from a source, and illumination results from its interaction with surfaces upon which it falls. This illumination alters the surface appearance, making it appear brighter or darker with particular colors.
However, the brightness and color perceived by the eye may sometimes interfere with what is considered useful or acceptable. Light may be created by flowing an electric current through filaments like in incandescent lights, through arcs between metal rods or carbon rods, or appropriate gases like neon and other gas tubes.
In several lamps, the light is due to fluorescence elevated by radiation emerging from the moving of electric current through mercury vapor. Some bodies reflect light at some rate, and when illuminated from the primary source they become secondary sources of light. A good example is the moon, which illuminates Earth through the reflected light emerging from the sun.
Illumination is measured in lux or lumen/m2.
Laws of Illumination
Light is an essential element in human life and the day-to-day activities of human beings eventually depend on the light. Where there is no natural light, the use of artificial light is required. Artificial lighting is generated electrically, because of its cleanliness, ease of control, accuracy, and stable output, as well as its low cost it is taking an increasingly major part in modern everyday life.
The science of illumination engineering has become of major importance. Light is a form of luminous energy. Several forms of incandescent bodies are the reference of light and the light radiated by such bodies depends upon the temperature of bodies. Heat energy is emitted into the medium by a body that is much warmer than the medium surrounding it. The heat of the body can be categorized as red-hot or white-hot.
Table of Content
- Illumination
- Important terms
- Properties
- laws of Illumination
- Solved examples
- Advantages
- Disadvantages
- Applications