Lighting in electrical projects

Quantities of basic lighting units .

Luminous flux

It expresses the sensitivity of the eye to the light energy produced by radiation . It is measured in units called lumen and symbolized by ) LM ( .The amount of flux varies from one lamp to another according to its type and power

Luminous Intensity

It expresses the ability of a light bulb to emit a light flux in a specific direction. It is denoted by the symbol (I)

Illumination

The amount of light flux falling perpendicular to a unit area. It is symbolized by the symbol (E).

Polar curves

a light distribution curve is a visual representation of the light diffused by a luminaire. This graph tries to transpose a three-dimensional concept onto a two-dimensional medium .

Ø Brightness

Brightness is defined as the ratio between the intensity of the light and the apparent area of the light source.

There are two types

The brightness of the light source. It is denoted by the symbol L and is measured in Lambert.

The brightness of the bright object on which the light falls. It is symbolized by the symbol B and measured by the lux.

Ø GLARE

Glare occurs when looking at a light source provided that the brightness ratio is greater than 1.5 lumber.

Ø Color Rendering Index (CRI)

is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with an ideal or natural light source. Light sources with a high CRI are desirable in color-critical applications.