LED Lighting Technology
LED = Light Emitting Diode
it is an electronic semiconductor that emit light radiation by providing electical curent.
For this reason it is resistant to shock and vibration unlike fluorescent lamps, halogen etc.
The technological progress has led to the production of LED in high efficiency and some chips exceed the output of 100lm / w, thus leading to excellent energy saving. Further LEDs are characterized by the long life (up to 25 times more than incandescent bulbs and 7 times larger than the sodium-mercury lamps).
They do not contain toxic metals (mercury and lead) and do not emit UV radiation, resulting in significantly more friendly use to humans and the environment, when compared with other technology lamps (halogen bulbs, halogen, sodium, mercury, etc.).
Luminous Flux (Luminous flux F)
It is the radiant light energy emitted by a light source in unit of time. Unit measuring is lumen (lm).
Defined in relation to the candela as:
1 lm = 1 cd•sr
Luminous power per area (Illuminance E) (lux)
The quantity of flux which receives a surface pointing vertically mounted in the direction of the light (lux = lm/m2). 1 lux equals to flux 1 lm, distributed uniformly over a surface area of 1 m2.
Brightness (Luminance L)
Is the brightness of an illuminated (eterofotus) or a light (light emitting) source as perceived by the 'average eye. " Unit measuring nit = cd/m2. And the lamps stilb = cd/cm2.
Luminous Efficacy (Luminous efficacy) (lm / w)
Defined as the ratio of visible light (or luminous flux) to the electrical power consumed and is measured in lumens per watt (lm / W).
Intensity (Luminous intensity I)
It is the ratio of luminous flux dΦ, which emits a light source into an elemental solid angle (dω) to this angle.
Correlated Color Temperature Light (CCT)
Refers to the color of the emitted light beam, meseured in degrees KELVIN. The higher the color temperature is the colder the color of the light source.
Color temperatures above 5000 K are called cold (CW), the lowest (2700K - 3000K) are called warm (WW), while those in the range 3300-5000 K neutral (NW).
Operating Voltage (Voltage) (Volt)
Is the voltage of the power supply, which can operate the lamp.
Nominal power (Wattage) (Watt)
Is the power in Watts, consumed by the lamp during operation. Based on this figure and in line with the efficiency of the lamp, we can calculate the electricity it consumes.
Color Rendering Index (CRI)
In easy terms CRI is the quality of light and is represented by a number from 1 (worse) to 100 (best). A CRI of 100 means the light has the same quality as sunlight, it is pleasant and all colors look natural. At CRI of 60 the light has an unpleasant feel and colors look unnatural (for example Skin appears less pink, and hence "unhealthy").