let there be light

LEDs have revolutionized our lighting. But do these lamps live up to their reputation? In the Lighting Testing Laboratory in Atlanta, TÜV SÜD is looking for answers. A visit to a place where the lights never go out.


leg 3  ■  São paulo ➡ atlanta  ■  9,250 Km  ■  Arrival 9.11.2015, 9:00 a.m.  ■  travel time 48 hrs  ■  11°C  ■  total distance 27,700 KM

The room is jet black except for one corner, where the computer’s control lamps glow. Suddenly a light goes on and a large mirror starts turning around a lamp, reflecting the light across the room to a detector that measures the luminous flux. “We measure the light flux with the goniophotometer,” says Lighting Lab Atlanta’s Program Manager Bryan Cubitt. The Atlanta facility is TÜV SÜD’s largest lighting laboratory, alongside the one in Garching, Germany. Cubitt is the master of a wide variety of light sources, especially LED lamps, but also vehicle lighting, streetlamps and airport runway lighting. His colleagues test light sources for their brightness, luminous flux, lifespan, color and energy efficiency.




Between 6 and 20 percent of the electricity generated globally is used for purposes of illumination. LED lamps and energy-saving bulbs with the same luminous efficacy require as much as 80 percent less electricity than traditional lamps—an enormous potential savings. But are these figures correct? Are LED lamps truly as long-lasting and environmentally friendly as manufacturers promise them to be? That’s exactly what the TÜV SÜD Light Testing Laboratories are testing. “We give our clients all the information they need for a competitive and sustainable product.”

Vehicle lighting is being tested on the other side of the building complex. The walls, floor and ceiling are also pitch black. A car’s rear light is installed and sensors over 30 meters away measure its luminosity.

The Integrating spheres, in contrast, are blindingly bright—they are coated inside with the purest white available. It reflects 98 to 100 percent of the light and ensures that every point within the sphere—which can measure over 3 meters in diameter—has the same luminosity. Across from it are the test stands for energy-saving bulbs and LED lamps. 

 Up to eight thousand light sources are regularly turned on and off here in special environmental chambers, twenty-four hours a day. And at the end of the day, when the last of the twenty employees leaves the building, they  may close the door behind them, but there’s one thing they never do: turn out the lights.


Lights and Shadows