EN 12464-1: “The Lighting of Workplaces”
This European standard is about the quality aspects of lighting workstations and their direct environment. It also has tables with lighting requirements in accordance with the type of work and the visual task.
Definition of workstation and environment
The standard makes a distinction between the work area and the environment. Don't you know yet where the work area will be? Or do you like it to be flexible? In that case choose the best illuminance in the entire work area. Or define the workstations with task lighting and have basic lighting in the rest of the area.
Luminance control in computer screens
Lighting can also cause interfering reflections on modern computer screens. That is why the standard specifies requirements to control the average luminances. For normal workstations, a limit applies of 1000 cd/m² or 200 cd/m² depending on the computer screen. This limit applies for angles starting from 65° all-around. For critical computer screen activities this starts from 55° all-around.
The standard specifies two measures to limit direct glare. A minimum shielding angle in all directions is specified depending on the lamp luminance. Also, a Unified Glaring Rate, UGR limit value (UGRL) is specified for every visual task. The standard values range from UGR 16 (not blinding) to UGR 28 (blinding).
Improved colour rendering
For the colour rendering index (Ra), the standard specifies a minimum requirement for practically all tasks. The higher the number, the better the colour rendering. The choice of lamp is decisive for this. In rooms where people need to stay a long time, lamps with an Ra of at least 80 are required.
Supported maintenance factor
In a new installation, all the surfaces of the luminaire are clean, the lamps emit the full luminous flux and the surface of the luminaire and the room have optimal reflector properties. When the installation has been used for some time, the light yield will reduce due to a drop in light output of the lamp, the possible failure of the electronics or the lamp, etc. EN12464-1 prescribes that in the development of a lighting solution a maintenance factor needs to be used that compensates reductions.