Human Factor

  The concepts of illumination and luminance are associated with the quantity of light falling on or emanating from a surface, respectively. Illumination is related to the amount of light falling on a surface or an object. Luminance is related to the amount of light coming from an object, such as a video display terminal or a wall.  Luminance is associated with our subjective impression of brightness. The farther you move away from a light source, the more the intensity of illumination. In fact, it decreases as the square of the distance. If you double the distance between an object and a light source, the illuminance measured at the object drops to one-fourth its previous level. sonable range of distances. The reason for this has to do with the way luminance is defined mathematically. Our experience confirms that a wall doesn’t become less bright simply because we move away from it.

Illumination  -  lighting both within the general working environment and also in  the locality of the engineer and the task he is carrying out.  Amount  of light striking a surface.  To work safely and efficiently, proper lighting conditions is required.  Cones in the retina of the eye  require good light to resolve fine detail. Colour vision requires adequate  light to stimulate the cones.  Inappropriate or insufficient lighting can lead to mistakes  in work tasks or can increase the time required to do the work.    Illuminatio n  availableability is important where the engineer needs it (i.e. both  in the hangar and one the line). Supplemental task lighting must be adequate in  terms of its brightness for the task at hand , which is best judged by the engineer.  When using task lighting , it should be placed close to the work being done,  but should  not be in the engineer’s line of s...