Studie om individers kontrastkänslighet och preferenser för horisontell och vertikal belysningsstyrka

Sammanfattning: The purpose of this study is to survey and evaluate if the individual contrast sensitivity and preferences for horizontal and vertical lighting level correspond to the values that standard SS-EN 12464-1 recommends for the workplace- and surrounding light levels. This study examines if lighting should be adapted after the individuals’ need or if a general value can be found that will cover every individuals’ need for a workplace and surrounding light level. This study also examines if parameters like sex, age and/or glasses/lenses have an effect on the amount of lighting that the test subjects need. Lastly we compared the values concerning the relationship between workplace- and surrounding light levels with standard SS-EN 12464-1’s recommendations. The study is carried out with an experimental design that surveys 220 test subjects who were chosen by a selection of convenience. The test subjects did perform a test where they estimated their individual need for lighting in office environments regarding lighting for workplace and its surroundings. Every test subject carried out the test where they repeated the same attempt three times, to establish if the individual lighting need oscillated or if it was constant, whereupon the results were analyzed, compiled and compared to standard SS-EN 12464-1. The results show that the minim- and maxim value for the test subjects is between 70 – 4300 lux. The result varies with different parameters such as sex, age and glasses/lenses. We could also state that the relationship between workplace- and surrounding light levels is slightly higher than what standard SS-EN 12464-1 recommends, which should be taken into consideration when planning future lighting constructions. Based on the results in this study, our conclusion is that standard SS-EN 12464-1 does not cover the needs on the comfort levels that the test subjects indicated. The values that the test subjects indicated differ from the values that standard SS-EN 12464-1 recommends. Since there is a huge spread of the experienced need for lighting between individuals and age groups, we draw the conclusion that general values of measure can’t be applied as a standard on neither workplace- nor surrounding light levels. To fulfill the needs that users have, the lighting construction should be adapted for the individual and give a lighting flood that will fill the individual needs for workplace lighting.