LED Lighting
Whether it's commercial, retail, industrial, or domestic, one of the largest energy spends in your building is lighting.
LED Replacement Bulbs
Lighting terms
Watts, Lumen, and Lux
In trying to compare lighting, there are some key characteristics involved relating to power used, light provided, effectiveness of the light provided, quality of the light provided.
Wattage (measured in Watts) is the power required to operate a light fitting. It refers to the total electricity that is consumed in providing the light.
The lumen (lm) is a standardised unit of measurement of the total amount of light (packets or quanta) that is produced by a light source
Lux is a standardised unit of measurement of the light intensity. For example 1 lux is equal to the illumination of a surface one metre away from a single candle.
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Wattage (measured in Watts) is the power required to operate a light fitting. It refers to the total electricity that is consumed in providing the light.
The lumen (lm) is a standardised unit of measurement of the total amount of light (packets or quanta) that is produced by a light source
Lux is a standardised unit of measurement of the light intensity. For example 1 lux is equal to the illumination of a surface one metre away from a single candle.
To find information these terms and examples click here...
Colour Temperature and Colour Rendering
These terms relate to the quality of the light experienced.
Correlated Colour Temperature (CCT) describes the relative color appearance of a white light source, indicating whether it appears more yellow/gold or more blue, in terms of the range of available shades of white.
Color Rendering Index (CRI) measures the ability of a light source to accurately render all frequencies of its colour spectrum when compared to a perfect reference light of a similar colour temperature.
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Correlated Colour Temperature (CCT) describes the relative color appearance of a white light source, indicating whether it appears more yellow/gold or more blue, in terms of the range of available shades of white.
Color Rendering Index (CRI) measures the ability of a light source to accurately render all frequencies of its colour spectrum when compared to a perfect reference light of a similar colour temperature.
To find information these terms and examples click here...
Lumen Maintenance
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Rated lumen maintenance life (Lp) is the elapsed operating time over which the LED light source maintains a given percentage of its initial light output. This is expressed as Lp where p is the percentage value. For example,
• L50 = Time taken for the light output to reduce to 50% of the initial lumen output, in hours. • L70 = Time taken for the light output to reduce to 70% of the initial lumen output, in hours. |
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• L85 = Time taken for the light output to reduce to 85% of the initial lumen output, in hours.
IES LM-80-2008, & IES TM-21-2011
IES (Illuminating Engineering Society) LM-80-2008, “Measuring Lumen Maintenance of LED Light Sources” (“LM-80”) is the industry standard that defines the method for testing LED lamps, arrays and modules to determine their lumen depreciation characteristics and report the results.
IES TM-21-2011, “Projecting Long Term Lumen Maintenance of LED Light Sources” (“TM-21”) is the technical memorandum that recommends a method of using LM-80 test results to determine the rated lumen maintenance life (Lp) of LED lamps.
IES (Illuminating Engineering Society) LM-80-2008, “Measuring Lumen Maintenance of LED Light Sources” (“LM-80”) is the industry standard that defines the method for testing LED lamps, arrays and modules to determine their lumen depreciation characteristics and report the results.
IES TM-21-2011, “Projecting Long Term Lumen Maintenance of LED Light Sources” (“TM-21”) is the technical memorandum that recommends a method of using LM-80 test results to determine the rated lumen maintenance life (Lp) of LED lamps.