Calculation of the performance parameters of tungsten filament lamps using the exponent rules

Abstract

The experimentally known values of the 14 exponents associated with the exponent-rules for vacuum and gas-filled tungsten filament lamps are utilized to obtain the temperature dependence of performance parameters such as power demand, lumen output, life and efficacy. It is also shown that the data on emissivity of tungsten reported by Jones and Langmuir are consistent with theory in contrast to those obtained by Roser and Wensel. Further, the analysis predicts a higher power loss factor and a longer life for gas-filled tungsten filament lamps than for vacuum lamps. © The Chartered Institution of Building Services Engineers 2010.