From LEDs to stadium projectors, the CSTB assesses the quality of lighting products. It also works to improve visual comfort with natural and artificial lighting, from the level of the component to the building and all the way to the city scale. In addition, the CSTB conducts research on the health hazards associated with lighting technologies. It has two research and test facilities for lighting (in Nantes and Grenoble) with advanced and one-of-a-kind equipment.
Improving lighting quality
The CSTB test facility team in Nantes works with manufacturers and research partners (the XLIM laboratories in Poitiers, Inria in Rennes and ENTPE in Lyon, among others) to improve the visual comfort of natural and artificial lighting. Their mission: to develop new test equipment and measurement methods for lighting sources, and to characterize the light properties of building surfaces and materials.
For very precise measurements of light distribution in space, there is a near-field goniophotometer, which characterizes luminaires at very short distances (1.50 meters). The CSTB also has advanced expertise in the characterization of LED lighting products.
To study the lighting of a space, you must know the optical properties of the surfaces. The CSTB examines the reflective properties of materials (concrete, carpeting, etc.) using a Bidirectional Reflectance Distribution Function (BRDF)1 measurement device. The data is very useful for designing visual ambiance in auditoriums and museums, for example. It is also increasingly demanded by the automotive and design sectors for developing new colors and textures, which help to provide unique visual identities.
In construction projects for buildings, especially major structures (airports, stadiums), it is essential to consider natural lighting. This can be simulated using data measured and compiled by a CSTB light weather station which, networked with other laboratories around the world, has been measuring diffuse and overall illumination of the sky every 10 minutes, for over 30 years.
And what about pool lighting? To characterize underwater luminaires, the CSTB has specific measurement equipment designed in spring 2015 and unique in the world.
Assessing lighting products
The CSTB test facility teams provide their support to manufacturers and distributors of artificial lighting materials. At the Grenoble site, experts are performing standardized tests on materials such as lamps, luminaires, lighting modules and all types of lighting devices (for example, flashing alarm lights, headlights and portable lighting). The testing outcomes are useful in drafting specifications for lighting products.
To ensure the quality of products and user comfort and safety, the CSTB uses:
- A far-field goniophotometer to characterize lighting products 3 meters away (IES or LDT standardized data);
- Three integrating spheres outfitted to a spectroradiometer for measuring the quality of light from lighting products of any size: 30 cm, 1 m, 3 m;
- A photobiological hazard measurement device to assess the dangers to the eye posed by optical radiation and determine exposure levels in accordance with current regulations.
Two test benches unlike any other in the world are used to measure and characterize the functioning of infrared occupancy sensors:
- One to test passive infrared sensors, which are mostly used to control lighting and intrusion alarms;
- Another, developed in 2015, to characterize low-resolution imagers, the latest-generation infrared sensors for buildings, and public lighting.
Studying lighting quality on-site
The CSTB can perform complete studies of various light sources in buildings to improve occupant comfort. To do this, it uses many mobile facilities. It carries out interior and exterior lighting diagnoses for natural and artificial lighting. In addition, the CSTB can characterize the performance of new-generation products using standardized on-site measurements.
To contribute to the continuing development of standards, CSTB teams in Nantes and Grenoble work with other research teams in France and at an international level on this subject.
- The BRDF device measures reflectance variations based on lighting and observation of the material.