QUECKSILBERDAMPF-NIEDERDRUCK-ENTLADUNGSLAMPE

摘要

A low pressure mercury-vapour discharge lamp includes a quantity of a binary amalgam so disposed that, during operation, it is heated to provide a suitable mercury vapour pressure. The amalgam consists of mercury and magnesium in the form of any one member (except the last) of, or an alloy of any two adjacent members of the series HgMg, Hg3Mg5, HgMg2, Hg2Mg5, HgMg3, Mg. The amalgam is chosen so that anticipated loss of mercury from it during construction and/or operation of the lap lamp will not change it qualitatively, and hence the vapour pressure of mercury will be maintained. A3:1 alloy (the mercury-richer component predominating) is preferred to provide manufacturing tolerance. The amalgam may be a sheet-metal element disposed on a mounting plate adjacent an electrode, the construction and arrangement of the element, plate and electrode determining the temperature attained by the amalgam.