LED Technology
LED Spectrum
LEDs in LIGMAN luminaires provide options from neutral white (W40, 4000K) warm white (W30, 3000K) and extra warm (W27, 2700K). Some fixtures offer tuneable-white (2700K to 6500K) or RGBW (Red, Green, Blue, White) colour-changing sources. LEDs do not generate UV or IR radiation and have very low colour fading rate as compared to conventional lamps.
LED Colour Rendering
The colour rendering index (CRI or Ra) is a standard measure of how well a light source reproduces the colour of an object compared to a standard reference (tungsten) source. The index value is computed from how well the light source under test reproduces the colour of 8 standard pastel colour swatches. Generally, for LED fixtures, a colour rendering index of between 80 and 90 is stated as good and a value between 90 and 100 considered as excellent.
LIGMAN provide fixtures with a tested CRI value >80 for general indoor and outdoor as standard, however, CRI >90 is optional upon request.
LED Colour Deviation
SDCM is an acronym which stands for Standard Deviation Colour Matching and it has the same meaning as a “MacAdam ellipse”. The SDCM value, defined from visual colour matching experiments, shows the standard deviation of the colour discrimination variations from a specific center on the xy chromaticity diagram based on ANSI engineer Davis Lewis MacAdam described. Increasing size of ellipse can classify the maximum colour deviation of light sources referred to as MacAdam ellips of a certain step size SDCM.
LIGMAN uses high-power LEDs and Chip-on-Board LED (COB) with 3 SDCM (or 3-Step MacAdam ellipses) as the standard suitable for most
indoor and outdoor project applications.
LED Lumen Maintenance
At LIGMAN we design our own LED light engines to maintain the thermal equilibrium of our luminaires below the critical temperature range and we properly input the optimum driving current and operating conditions to state maximum luminous flux output together with the stated useful life performance of the LED luminaires.
We publish the rated values of L90/B10, L80/B10 and L80/B50 for our entire range of LED products, which indicates the lifetime expectancy of the LEDs used. As an example, a rated lifetime of L90/B10 to 60,000 hours means that the LEDs maintained lumen performance is over 90% after 60,000 hours. It also indicates that only 10% of LEDs will not achieve 90% of their original luminous flux after 60,000 hours.
TM-30-15 (LATEST)
TM-30-15 is the latest method adopted by the Illuminating Engineering Society Of North America for quantifying colour rendering properties of light sources, these results distinguish both colour fidelity and colour gamut and provide a far more comprehensive framework for better interpreting chroma and hue shift associated with light sources as compared to the standard Ra rating method.
In keeping with the new measurement standards and meeting market requirements, LIGMAN now provides TM-30-15 as well as CIE Ra and CIE R9 reports for all fixtures.