Light Loss Factors for Sports Lighting

摘要

This article describes an empirically derived light loss curvenand Total Light Loss Factor (LLFT) for sports lighting applications. Annempirical model was developed by comparing the illuminance fromninitial design computations against measured illuminance, on a pointby-npoint basis, for 37 sport fields. The study was limited to lightingnsystems that employ 1500W metal halide lamps with a rated life ofn3000 hours. The model, which is based on more than three thousandnmeasurements and an equal number of computed data points,ndemonstrates that values for LLFT of 0.75, 0.69, and 0.65 arenrepresentative of real-world sports lighting applications at 1200, 2100nand 3000 hours, respectively. The model suggests that it would benpragmatic to use a LLFT of 0.69 as part of the design calculations fornnew sports fields. This recommendation is markedly different from thencommon practice of using a LLFT of 0.80.