DefinePK

Abstract

In this work, the effect of self-absorption on the lamps' luminous flux measurements at the NIS-Egypt integrating sphere facility has been studied. With integrating sphere photometry comes errors from self-absorption. Industry standards recommend applying absorption correction techniques for situations where the physical configuration and characteristics of the lamp or LED under test differ from the reference lamp. Self-absorption correction is critical since the physical size and shape of SSL products and lamps under test are typically very different from the reference lamp size and shape. In our study, different groups of lamps under test are used to determine its luminous flux as well as the self-absorption factor; High-Pressure Sodium (HPS), High-Pressure Mercury (HPM), Metal Halide (MH), Double-Ended Halogen (DE), Compact (C1,C2,C3) and LED (W1,W2,W3). Results show that the self-absorption factor has a considerable effect that can reach up to 7% on the measurements of total luminous flux such as in (DE) lamps. This effect must be considered and added to the measured luminous flux as a correction. Unless the test lamps are the same type as the standard lamps, the self-absorption should be measured and corrected.