Glossary

Glossary

Our product catalogue contains a lot of technical terminology that may not be clear to ones without special education. Our purpose is to make LED technology closer to people. So we’ve created a short dictionary of LED terms explained in simple words. We hope it will help you to get into the technology and to make a right choice. 

 

Beam angle The angle between the two directions opposed to each other for which the light from a light source is emitted. Some manufacturers use the half-value angle - the angle between the two directions for which the luminous intensity is half that of its maximum.
Candela (cd) A unit that indicates a luminous power of a light source in a particular direction. One candela is approximately equal to a light power of a common candle.
Chip An active light-emitting part of an LED. A semiconductor material of small size also called as the crystal.
Color rendering index (CRI) A quantitative measure of compliance between the color of an object illuminated by a specific light source and its natural color. The highest possible CRI is 100 and it means that the light source reveals the colors the most accurately. The lower is the CRI of a light source the more it distorts the colors.
Color temperature (CCT) The temperature of an ideal black-body that radiates the light of the same color as a current light source. Bulbs with CCT between 2600 - 3500К emit warm yellow light. Cold white light has the temperature of 5500 - 6500К and natural daylight effect may be achieved between 4000 - 4500К.

Learn more about the nature and use of color temperature from our article Hot & Cold.
Dimmer An electronic device that allows to control the brightness of LED and incandescent bulbs.
Driver An electrical device for AC-to-DC conversion. Ensures LED’s functionality.
EU Energy Label (energy efficiency classes) An energy consumption labelling scheme which rates the appliances by energy efficiency and assigns classes from A++ to G to them. The most efficient appliances have A++ class. G class appliances are the least efficient.
Flickering, ripple level A quantitative measure of high-frequency brightness fluctuations level of a lamp. When it’s over 20% it may cause headaches and eye fatigue. Lamps with ripple level of 5-6% do not affect health.
Fluorescent lamp A gas-discharge lamp that produces visible light due to fluorescence.  An electric current excites mercury vapor inside the bulb which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow.
Halogen lamp A type of an incandescent lamp that contains a small amount of a halogen such as iodine or bromine in its bulb.
Heat sink The way of pulling away the heat produced in the lamp’s base. 
Incandescent lamp A lamp type which produces visible light due to current running through a wire filament and heating it.
Kelvin (К) A SI unit of absolute temperature. 1 kelvin is numerically equal to 1 degree Celsius. In lighting industry kelvin degree is used for color temperature indication.
Kilowatt-hour (kWh) A unit for measure of current consumption in household. For example, if a 100W lamp works for 10 hours it consumes 1000Wh or 1kWh of energy.
L70 The characteristic that indicates the lifetime of a LED lamp. It is defined as the time it takes until its light output, or lumen maintenance, reaches 70% of the initial output.
LED (Light-emitting diode) A p–n junction diode, which emits light when direct current is running through it. The light is produced due to recombination of electrons with electron holes which releases energy in the form of photons.
Lumen (lm) The unit of luminous flux. In LED industry is used for lamp brightness indication.
Luminous efficacy The number of lumen produced on 1 Watt of consumed energy. Measures how well does the lamp produce light.
Luminous intensity (candela) A measure of light power emitted by a light source in a particular direction. The SI unit of luminous intensity is the candela.
Luminous flux (lumen) The measure of the perceived power of light. Is measured by the impact on human eye and does not depend on direction.
Lux (lx) The SI unit of illuminance and luminous emittance. One lux is equal to one lumen per square meter.
OLED An organic light-emitting diode which contains organic compounds in its emissive electroluminescent layer and emits light in response to an electric current.
Power factor A physical quantity that measures the effectiveness of energy consumption by appliances. If the power factor of the lamp is higher than 0,85 it is considered to be efficient. The low power factor increases the energy lost in the system thus adding extra coins to electricity bills.
Rated frequency The frequency of the alternating current oscillations in an electric power grid in which the lamp operates. In most of countries it is 50 Hz, although in the Americas and some parts of Asia it is 60 Hz. Some countries(like Japan) use both.
Rated voltage, VAC Voltage of AC electric line in which the lamp operates. 220 VAC is a typical value for residential networks.
Watt (W) A unit of power which expresses the amount of energy consumed by bulbs.
Wattage equivalent In our catalogue this is the wattage of an incandescent bulb which emits the same luminous flux as a current LED bulb.

 

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