Additional lighting is required for the chalkboard and further vertical demonstration and information surfaces just as it is for visual task areas in specialised classrooms or at individual experimentation workstations or in the podium area of large lecture halls.
For chalkboard lighting, EN 12464-1 specifies a value of 500 lx. The reference area (visual task area) is the entire chalkboard surface including possible folded parts and the wall area above the board for boards which can be pushed upwards. For this reference surface, the uniformity requirement of 0,7 applies as well. Reflections on the chalkboard must be avoided. One example for chalkboard lighting is depicted in figure The values apply when the room lighting is switched on at 300 lx.