FT-IR Diagnostics of Tungsten-Halogen Lamps: Role of Halogen Concentration,Phosphorus,Wall Material,and Burning Environment

A 2⁴ factorial design matrix experiment is conducted to measure the effects of four different parameters on the HBr and CO levels in tungsten-halogen lamps as a function of burn time. The two gas species are measured at room temperature with the use of Fourier Transform Infrared (FT-IR) spectroscopy. The four parameters varied are (1) initial halogen concentration (as CH₃Br); (2) presence or lack of phosphorus; (3) bulb wall material; and (4) burning environment. The effects of these parameters on lamp efficacy and life are also analyzed. In addition, separate oven results show that a small amount of HBr is initially adsorbed onto the bulb surfaces. Also, results are given for separate CO measurements over a wider range of initial CH₃Br fill for bulbs with and without phosphorus.