Luminous flux Φ Unit: lumens [lm] Under flux Φ means all the light emitted radiation, weighted by the spectral eye sensitivity and photometric radiation equivalent km. Luminous intensity I Unit: candela [cd] A light source emits its luminous flux usually in different directions with different strengths. The light is emitted in a given space direction (solid angle) flux.
Illuminance E Unit: lux [lx] The illuminance E is the ratio of luminous flux to the illuminated surface. The illuminance is 1 lx as the luminous flux of 1 lm is evenly distributed over a area of 1m ².
Some typical examples: Moonless but clear night approx 0.01 lux Full moon, clear night approx 0.25 lux Sunset: 500 lux Gloomy winter: about 3000 lux Gloomy summer day: about 20,000 lux Sunny summer day: approximately 100,000 lux Public lighting: approx 1-20 lux Coarse assembly work: approximately 250-500 lux Good office lighting: about 500-1000 lux Fine assembly work: ca 1000-2000 lux Surgery Surgical illumination: approx 1000000 lux
Luminance L Unit: candela per square meter [cd / m²] The luminance L of a light source or an illuminated surface indicates how strongly the brightness impression.
Light efficiency η Unit: lumens per watt [lm / W] The light output indicates which returns the power consumption is converted into light.
The most important photometric formulas: Luminous intensity I [cd] = Luminous flux Φ [lm] / Space angle ω [sr] Illuminance E [lx] = Luminous flux Φ [lm] / Illuminated area A [m²] Luminance L [cd / m²] = Luminous intensity I [cd] / Observed luminous surface Shaft [m²] Light efficiency η [lm / W] = Luminous flux Φ [lm] / Electrical power P [W]
Light and radiation Light is electromagnetic radiation in the human eye, a brightness sensation is obtained and can be. Thus be seen This involves the radiation between 360 and 830 nm, a small portion of the known spectrum of electromagnetic radiation. Wavelength Unit: nanometer [nm] The different wavelengths are seen by the eye as different colors: red for the longest wavelength and violet the shortest. The greatest sensitivity of the human eye is at approximately 550 nm (yellow-green) in daylight and at 500 nm (blue-green) at night.
Color Mixing When mixing beams of light with LEDs "additive color mixing" are red, green and blue primary colors, usually referred to as RGB. The secondary colors are formed from light mixing the primary colors: magenta from blue and red light, yellow from red and green light and cyan from green and blue light. The primary colors to blend with each other and to dim all perceptible to the eye colors can be made. When LEDs are dimmed, each primary digital LED color can be set. Intensity values at 512 The total number of variations than 134,217,728, which is more than the eye can perceive, ie 16,000,000.
Temperature Unit: Kelvin [K] The color of light is described by the color temperature. One can distinguish three main groups:
LEDs can, although they have the same color of light, have very different color rendering properties, because the spectral composition of the light varies greatly. By default we provide the same color codes. It can happen that in the blue, white and warm white LED light color differences per production run. Colour rendering Depending on the location and the visual task the artificial light should be as good as possible color perception (as in natural daylight) insurance. The color perception by the human eye is dependent on the color rendering properties of the LED, in terms of Ra value on the basis of the color rendering index. The color rendering index indicates how the colors of an object as perceived by the eye, consistent with that of a reference source. In order to determine the Ra value is the color shift of 8 defined in DIN 6169 recorded test colors when illuminated with the corresponding light source or the reference light source. The smaller the deviation, the better the color rendering of the lamp tested. A light source with Ra = 100 displays all colors optimally, as the reference source. The lower the Ra value, the worse the colors are displayed.
Life Wholesale-XL uses various types of LEDs in its products. LED manufacturers predict that led a life up to 100,000 hours (MTBF) Mean Time Between Failure has either (mean time before failure). MTBF is the standard which is used in conventional lamp manufacturers to measure. To life However, like all standard light sources, LEDs suffer after some time, a reduction in lumen. Although able to radiate for an extremely long period of time, light from LEDs MTBF is not the only factor that counts in the determination of the life span. Reduction of lumen is also influenced by various environmental factors such as temperature, humidity and ventilation. The reduction of the lumen is further influenced by control, thermal control, power levels and a host of other design factors. Wholesale-XL systems are designed with expertise for environmental factors [temperature - 20 º C to 40 º C, humidity: 0-95% non-condensing humidity, adequate ventilation, and air volume]. Prolonged use outside this range, or the circumstances (or at the upper limits of these conditions), can ensure that reduces the life of the LED. In extreme cases, this can cause malfunction of internal components. Life information is based on tests conducted by both LED manufacturers and third parties.