Useful lumen definition

New EU regulation requires directional light sources and luminous flux to be measured within a 90° or a 120° cone. Luminous flux measurements are normally done at full 360° in all directions. However, the new EU regulations (EU No 1194/2012) requires that directional lamps are measured in a 90° or 120° cone, meaning that only light emitted inside the cone is counts as efficient luminous flux.

The Viso Light Inspector software v4.2 now supports limited spherical measurements, making it easier than ever to test your light sources against the new regulation.

The effect of normal 360° vs. 90° cone can be seen below.

The new regulation is expected to come into force in September 2013.

Click here to view EU regulation No 1194/2012 page 10

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