This paper describes an experimental integrating chamber for measuring the photometric and electrical performance of fluorescent light sources over a wide range of bulb-wall temperatures. The system was used to measure the relative light output and system efficacy of various solid-state ballasted fluorescent lighting systems for minimum bulb-wall temperatures between 20 degrees and 65 degrees C. For lamp-wall temperatures between 30 and 60 degrees C, the relative efficacies of the solid-state ballasted systems were found to be less sensitive to changes in bulb-wall temperatures than standard or efficient (low-loss) core-coil ballasted systems.