Luminous Flux (Lumen)

The fundamental measure for electromagnetic radiation emitted by a source is the radiant flux (W) - a measure of the rate of flow of energy emitted by the source.

In lighting, the radiant flux is multiplied wavelength by wavelength by the human photopic (daytime) spectral sensitivity to visible light (380nm ~780nm) forming the metric Luminous Flux.

The SI (System Internationale) unit for luminous flux is the lumen. The lumen (Lm) is therefore a measure of the total amount of light (luminous flux) emitted per second by a light source and can therefore be used to compare the performance of different light sources and forms the basis for lighting calculations.


Colour Rendering Index

Recent spectral measurements for the MONOFLEX range of PCBs can be found below. This shows the exact correlated colour temperature (CCT) of each light source measured and the corresponding Colour Rendering Index (Ra). The results show the standard 2700K Samsung (S30 & S60) LED to have an impressive 87 Ra. Yet more impressive data from the Samsung LM561B LED!

  Custom Packaged Osram Duris E3 Sansung LM561B
LED Type C42-2200K C42-2700K C112-2700K C112-3000K S30-2700K S30-2700K-IP65 S60-2700K
CCT 2215 2905 2714 3086 2737 2664 2794
CRI Ra 80 86 85 85 87 86 87