摘要: |
Light-emitting diodes (LEDs) are now commonly used in airfield lighting applications due to technology improvements and their potential benefits to pilots and airport operators. One such benefit is the potential to provide more reliable operations and reduced maintenance costs through longer useful life than incandescent lamps. However, airfield LED luminaires are relatively new and no sufficient long-term performance test results are currently available to validate their long-life potential. More importantly, there is no agreed upon definition of useful life for airfield luminaires. As a first step to address these needs, long-term testing of selected airfield luminaires are being conducted in support of the Federal Aviation Administration�s (FAA) efforts in this area. The main objective of these long-term tests has been to understand the performance of luminaires under realistic conditions, and thus the test conditions have included three LED board temperatures that are expected to represent a reasonable range of operating environments. While testing in a given range is valuable because it offers the opportunity to interpolate to other conditions, it is still necessary to understand the actual conditions that luminaires experience in the field due to ambient temperature (i.e., based on geographical location) and based on the luminaire�s light output (i.e., dimming steps 1-5). The purpose of the test is to monitor the temperature of operation of LEDs inside different types of luminaires under different operating conditions, based on geographical location and at one or more light output settings. These values can be used to better estimate light output depreciation based on current knowledge and to inform the conditions used in future laboratory tests. |