Tuesday, November 30, 2010

Regarding the brightness of lights

It is difficult to know what the brightness is just from a Watts figure. Although people typically talk about watts when thinking about light brightness, this is actually the power requirement not the Lumen light output.

This was not a problem when there was only one type of light but today there are many types such as – incandescent, Fluorescent, compact fluorescent, low/high pressure sodium, Tungsten Halogen, LED, etc – and all of these use different amounts of power (watts) to give a similar brightness in proportion to their efficiency. The most efficient of all DC lighting at this time are LED’s and SEC’s particular LED technology is up to more than 200% more efficient than most of our competition. This means that we can offer very bright light with very low electrical power requirement.

The correct measure of brightness is Lumens and this is a universal measure regardless of the power requirement i.e. – a 2400 Lumen LED light will give the same brightness as a 2400 Lumen Fluorescent light, but the difference is that the 2400 LED light may only require (as in our case) 25% of the power required by a Fluorescent light.

I hope this explanation helps you to understand why the Watts value is fairly meaningless without knowing (ideally) the Lumen value, or at very least the type of lighting and the watts requirement.

In the case of Street lighting, the other key aspect is the pole height as this will affect the Lux value, which is the brightness for a given area on the ground. We really need to know this information in order to estimate which product will be most suitable from our range. Typically SEC Solar Powered Streetlights are designed to provide 10 to 15 Lux on the road.

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