A light emitting diode (LED) is a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor, that recombine with electron holes, release energy in the form of photons(light).
2. Solid State Lighting:
Lighting devices that do not contain moving parts or parts that can break, rupture, shatter, leak, or contaminate the environment. LEDs do not use electrical filaments or gasses to produce light.
Lumens is the measurement of brightness emitted by an LED as perceived to the human eye. The higher the lumens are, the brighter the light appears to be. Make sure you check on lumens produced by an LED to determine which suits your need best before purchasing one.
A watt is a unit of electrical power used in the measurement of energy consumption.
Oftentimes, you may see lumens and watt together. For example, an 18W eurth LED fixture produces 1980lm. Meaning that it produces 1980 lumens of light as output by consuming 18W of current as input. Meanwhile a standard 60W incandescent bulb produces 800lm.
The ratio of the number of photons emitted from the LED to the number of electrons passing through the device. It indicates the ability of a light source to emit visible light by consuming a given amount of power. This is calculated by measuring the lumen output then dividing by given Watt input.
Lux is a unit of lumens or light falling onto a surface. One lux is equal to one lumen per square meter. Simply it is the measurement of intensity of light. The main reason for measuring light intensity is to ensure that minimum standards of illumination are being met.
7. CRI (color rendering index):
This is the ability of an LED light to show realistic colors of things such as furniture, artwork, jewelry and even fruits in the bowl in your kitchen. CRI is measured on a scale from 0 to 100. A CRI of 80+ is the industrial standard for most applications.
8. CCT (Correlated color temperature):
The main benefit with LED lighting fixtures is, many of them offer a choice of color temperature differentiating various hues of white light. Generally, CCT is measured in kelvins(k), on a scale from 1,000 to 10,000. Light with higher degrees of kelvin will be close to sunlight. Amber light or warm light generally falls at 2700k - 3000k. If you go further at 3500k-4000k, you will be getting a cooler hue of light.
Choose the appropriate hue that suits your mood, taste and best serves your purpose.
9. Amp & mAmp:
Ampere (Amp) is the measurement of electric current. Amp = Watt(w)/Voltage(v). Milli Ampere(mAmp) is 1/1000 or 0.001 of 1 ampere (Amp). When using LED strips, it is necessary that current drawn from the LEDs should be less than 1 ampere. In this case mAmp’s are used to determine the current drawn.
In the industrial production of LEDs, every batch contains LEDs of various characteristics like luminosity, color temperature, voltage and color location. Most of the manufacturers sort their production on the basis of the above. This process of sorting is called Binning.
11. IP rating:
IP is an acronym of “Ingress Protection”. IP rating defines the ability the level of sealing effectiveness of electrical components of a product and the level of protection it is having against solid objectives like sand, dust, dirt etc. and also against liquids.
IP65 Enclosure - IP rated as "dust tight" and protected against water projected from a nozzle.
IP66 Enclosure - IP rated as "dust tight" and protected against heavy seas or powerful jets of water.
IP 67 Enclosures - IP rated as "dust tight" and protected against immersion. for 30 minutes at depths 150mm - 1000mm
IP 68 Enclosures - IP rated as "dust tight" and protected against complete, continuous submersion in water.
12. Average rated life:
An average rating, in hours, indicating when a large group of lamps have failed, when operated at nominal lamp voltage and current. The life of an LED is defined as the operating time in hours for the lamp to reach L70 which designates 70% lumen maintenance (or 30% reduction in initial lumen output).
The average rated life of an LED is 50,000 hours. Meaning that an LED can last up to 50,000 lighting hours when operated at line voltage.
The method of controlling the operating temperature of the product by designing a path for heat to leave the body of the lamp using heat sinks and improved airflow. An important point to keep in mind is that LEDs generate 98% less heat when compared to standard incandescent bulbs and around 20% less heat than CFL bulbs.