High-pressure sodium vapor lamp and ternary amalgam therefor

摘要

A high pressure sodium vapor lamp for operation at a sodium vapor pressure of at least 60 Torr and in which the start-up interval of variation of lamp operating voltage is reduced by charging the lamp with a ternary amalgam of mercury, sodium and a third metal selected from the group consisting of indium, gallium and tin. The atomic proportion of the third metal exceeds that of the mercury but does not exceed that of the sodium in the amalgam, and the atomic proportion of sodium is at least twice but not over four times that of the mercury.