Know-how: a brief LED glossary

LED technology is complex. Knowledge of some of the basic concepts will go a long way to helping you understand the principles involed, so we have prepared the following glossary to help you.

Beam Angle
Indicates how broadly the light is emitted forwards from the lamp and is defined as the angle between two lines that extend from the LED lamp and intersect the points where luminous intensity is 50% of its maximum value.

In the production of modern high-output LEDs manufacturing tolerances are unavoidable even with the smallest fluctuations in the parameters. The semiconductors are therefore sorted and classified after production according to their colour values and efficiences. All the LEDs that have similar values are places in the same bin. The narrower the tolerances the greater the quality of systems that consist of more than one LED.

(Latin for tallow candle) Is the photometric SI base unit for luminous intensity and is the luminous flux emitted by a light source particular direction (the luminous flux Im emitted in a particular direction in a solid angle sr). The symbol is cd.

LED lamps are still more expensive to purchase than lamps based on other technologies. Over their lifetime however they are already a cost-effective alternative to incandescent and halogen lamps.

Colour spectrum & definition of colour temperature
The colour spectrum is that part of the electromagnetic spectrum that can be perceived by the human eye without any technical ads (approx. 380 to 780nm). The colour temperature is a measure of the colour impression of a light source measured in kelvin (K). For LED lamps the colour temperature typically ranges from 2700 K to 6500 K.

CRI (Colour Rendering Index)
Indicates the quality of colour rendering of artificial light sources. The symbol used is Ra.The maximum value is 100, which means no falsification of colours by the light source. Incandescent lamps can achieve this value. LED lamps have a typical value of Ra 80, but can achieve Ra 90 and more. 

Our range includes dimmable LEDs. Most of the conventional dimmers available on the market (leading-edge/trailing-edge phase dimmers) have been designed for incandescent lamps and are therefore rated for higher minimum loads (W) than LED lamps offer. There may therefore be some restrictions in terms of functionality.

(Light Emitting Diode) Is an electronic semiconductor component. If current flows through the diode it emits with a wavelength that depends on the semiconductor material.

A lens is an optical component with two refractive surfaces, at least one of which is either convex or concave. In LED lamps the function of a lens is to focus or disperse the light and therefore define the beam angle.

LED lamps have extremely long lives. However, their light output diminishes over time. We define the lifetime of its LED lamps as the operating time in which the LED lamps produce more than 70% of their initial light output.

(latin for light or torch) Is the photometric unit of luminous flux. Luminous flux is a measure of the entire visible radiation emitted by a radiation.

Our LED lamps are extremely durable and do not contain any mercury. However, beacause they contain electronic components they must be desposed of as waste electrical and electronic equipment at the end of their life.

TCO (Total cost of ownership)
TCO includes all the costs over the entire life of a lamp or for a particular operating time. It covers procurement costs, relamping costs and operating costs (power). LED lamps now pay for themselves through their long life and low power consumption.

Is the SI unit of power and was used for incandescent lamps as an indication of their light output. Since modern energy-saving lamps and LED lamps consume far less power to achieve the same brightness, however, the wattage is no longer as meaningful. The lumen value is now used instead.