The accurate calculation of midpoint ratio for installations of linear luminaires is a lengthy operation, except when carried out using a computer. A simplified method based on the use of aspect factors is therefore proposed. Its accuracy is compared with the full aspect factor method and a method which treats the luminaire as a symmetrical point source. In all the examples taken, the simplified method is more accurate than the point source method, but shows some differences with the full aspect factor method. It is judged to be sufficiently accurate for practical purposes.
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References
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