distance of exposure from a lamp or lamp system
Note 1 to entry: For lamp safety evaluations, the exposure distance is the nearest distance consistent with the application of the lamp or lamp system. For lamps radiating in all directions the distance is measured from the centre of the filament or arc source. For reflector-type lamps the distance is measured from the outside edge of the lens or the plane defining the end of the reflector in a lens-free reflector.
Note 2 to entry: The exposure distance is expressed in metres (m).
Note 3 to entry: This entry was numbered 17-414 in CIE S 017:2011.