Effects of frequency and current on the electrode temperature of HID lamps

The electrode temperature has strong influence on the lifetime of HID lamps. The 800 nm spectral radiance distribution of a HID lamp electrode in a quartz arc tube were measured with a monochromator, which was calibrated with a tungsten ribbon spectral radiance standard lamp. Then the electrode temperature was calculated using Planck formula. The dependence of electrode temperature on time, rectangular waveform frequency, electrode position and discharge current were analyzed. The results show electrode temperature increases in anode phase and decreases in cathode phase. When the frequency increases, the electrode temperature decreases and becomes flat along with time. When the current decreases, the electrode temperature decreases and keeps almost the same waveform.