What Does Luminous Intensity, Luminous Flux?

Lighting concepts

What is luminous flux?

Is the total amount of light emitted per second by a light source.
The unit of measurement of the luminous flux is the lumen (lm), represented by the symbol Ø.

Example: a 100-watt incandescent bulb emits about 1,600 lumens of light per second flow to the environment.

What does light intensity?

Is defined as the concentration of light in a particular direction, signal per second. Represented by the symbol I and the unit of measurement is the candela (cd).

Where to use the yellow light bulbs and white light?

The white light provides a more dynamic environment ideal for work areas, yellowish light provides a more cozy environment ideal for rest areas.

As for the use of one or another lamp (more white or more yellow) or a combination of them, it is a question of taste, that is, depends on the purpose, harmonisation with the colors of furniture and walls each for your environment.

What does luminous efficiency of a light bulb lighting?

Is calculated by dividing between the emitted luminous flux in lumens, and the power consumed by the lamp in Watts. The unit of measurement is the lumen per Watt (lm/W). A lamp provides a higher luminous efficiency when the energy consumed to generate a given luminous flux is smaller than the other.

A incadescente of 60 Watt Lamp has a luminous flux of 864 lumens, so your luminsosa efficiency will be 864/60 = 14.4 lm/W.
A 15-Watt compact fluorescent lamp has a luminous flux of 900 lumens, soon your luminous efficiency will be 900/15 = 60 lm/W.

What are the requirements for a database project?

The lighting setup requirements depend on the type of work to be performed on the premises in question.The starting point of each lighting project will therefore always space itself, its construction details, your purpose, the work to be illuminated and the visual task involved.

The most important goal, designing a lighting installation for a work environment, is the provisioning of good visual conditions in the work plan.An additional goal should be the creation of a complete visual environment, providing a positive influence on performance and well-being of the occupants.

In environments used for demonstration or exhibition articles, the main purpose of enlightenment is to get an attractive presentation and impact. In shop Windows, aesthetic value and propaganda of illumination should dominate.

In everyday normal residential interiors, aesthetics and visual comfort lighting are predominant factors, for which only general guidance can be given.

In foyers, hallways, walkways and stairs, lighting is mainly focused on the guidance and security.

What is level of Illuminance or Illumination?

Is the amount of light or luminous flux that reaches a unit area of a surface per second. The unit of measure is the lux, represented by the symbol and a lux equals 1 lumen per square meter (lm/m2), relative illuminance values are found in standard NBR 5413-Illuminance of interiors, of the Brazilian Association of technical standards, which follows the trend of international standards.

What is Luminance?

Is the definition for the luminous intensity (cd) produced or reflected per unit area (m2) of a surface in a given direction. She is represented by the symbol L and the unit is candela per square metre (cd/m2).
The luminance distribution in the field of view of the people in an area of work provided by the various surfaces inside the area (light fixtures, Windows, ceiling, wall, floor and surface), should be considered as complementary to the determination of iluminâncias (lux) the environment, in order to avoid glare.

What is Uniformity?

The uniformity of illumination is measured by the ratio between the minimum and the average illuminance in illuminated area.
A good uniformity in lighting is required, in order to avoid shadows and ensure comfort and safety for the practice of the activity carried out in the area. The spacing between the lamps and the detachment of them in relation to the walls have direct contribution in the result of illuminance uniformity.

What is color temperature?

In order to have standardization among manufacturers of lamps, it was necessary to develop a system that ranks the colour of the light emitted by the lamps. This standardization has occurred around 1931 and was in charge of the CIE “Commission L Eclairage ´ Internacionalle” which adopted the “correlated color temperature method”.

The correlated color temperature is the temperature corresponding to the point in the “Locus of Planck” based on thermal radiation from a black body radiator or absolute. This means that when you heat a solid body (black body radiator or absolute) will begin to emit a red light and dark when the temperature increases the color changes to bright red, Orange, yellow, white and finally bluish white.

Comparing the colour of the light emitted by a particular lamp with colour emitted by the black body at a given temperature, it is concluded that this bulb emits light with temperature of this body, for example: heating a blackbody and next to it there is a light bulb lit, when the black body reaches the temperature of 2,700 Kelvin, emits a light with the same colour tint of the incandescent light bulb. The unit Kelvin was adopted, because at the time was the standard unit of temperature.

Today we have lamps with color temperature close to 3000 K, as for example the Super 83 or TLD/930, which we define as “yellow” lamps with color temperature close to 4000 K, as for example the Super 84 or TLD/940, which we define as “neutral” and lamps with color temperature close to 5000 K, as for example the Super 85 or TLD/965 , which we define as “super white”.