Abstract: The electric lamp according to the invention has a lamp vessel (1) of glass having an SiO.sub.2 content of at least 95% by weight, in which an electric element (3) is arranged. The lamp vessel is coated with an interference filter (5) of alternating layers of SiO.sub.2 and Nb.sub.2 O.sub.5.

Abstract: There is provided a solar collector comprising an evacuated transparent envelope having an absorber arranged therewithin. A duct containing a heat-transport medium is arranged at least partially within such envelope and is so associated with the absorber that heat derived from incident solar radiation is transferred to the heat-transport medium in the duct during operation. A reversible heatable hydrogen getter consisting of a partial metal hydride is positioned in the envelope, together with a fully hydrogenized metal hydride thermally more stable and having a higher affinity for oxygen than the partial hydride.

Abstract: The invention relates to a high-pressure sodium vapor discharge lamp which has a discharge vessel in which xenon and a xenon-absorbing substance are present. The xenon is absorbed partly in the absorbing substance. When the temperature is raised xenon is released.According to the invention, the xenon pressure P at room temperature has a value which satisfies 1 kPa.ltoreq.P.ltoreq.25 kPa. Herewith it is achieved that a lamp is obtained having good ignition properties and a high xenon pressure in the operating condition of the lamp, resulting in a large luminous flux.

Abstract: A halogen incandescent lamp having a light-pervious envelope containing a gas filling comprising a rare gas, hydrogen and bromine. The envelope also contains a tungsten filament and an oxygen getter. The oxygen getter consists of an intermetallic compound of at least one first metal from the group consisting of Ta, Ti, Zr, Hf and Nb and at least one second metal from the group consisting of Pd, Pt and Au, but which intermetallic compound is not a tantalum-gold or a niobium-gold compound.These intermetallic compounds are sufficiently stable that although they react with oxygen, they do not react with hydrogen bromide.Consequently the presence of such an intermetallic compound in such a halogen incandescent lamp does not interfere with the tungsten-bromine cycle, and thus the maximum quantity of the intermetallic compound which is present in such a lamp is not critical.

Abstract: The invention relates to an electric device provided with a switch which is constructed as a discharge tube which comprises at least two main electrodes and a reversible hydrogen getter.According to the invention the discharge tube contains a rare gas so that the current flow in the conducting state of the switch is mainly ensured by that rare gas. The non-conducting stage of the switch can be obtained by heating the getter. Namely, the hydrogen pressure in the discharge tube then becomes so high that the discharge in the tube is extinguished. Heating of the getter is preferably effected by the heat developed by the current between the main electrodes. This results in a self extinguishing breakdown element.

Abstract: Electric lamps having a gas-filled lamp envelope according to the invention have a hydrogen getter consisting of a coherent mixture of 65-90% by weight of zirconium powder having a particle size of 100-1,000 .mu.m and 35-10% by weight of nickel powder.

Abstract: A high-pressure discharge lamp having a hydrogen getter in the lamp vessel disposed in a metal envelope which is hydrogen-permeable. The hydrogen-permeable metal of the envelope is covered with a porous halogen-resistant layer. The atoms of the metal halides dissociated in the discharge can recombine at the porous layer so that blackening of the discharge vessel is mitigated.

Abstract: A high-pressure discharge lamp having a hydrogen getter in a metal envelope of which only a part consists of a hydrogen-permeable metal. The getter is arranged in the lamp in such manner that the hydrogen-permeable part of the envelope faces the discharge.

Abstract: In high-pressure discharge lamps an electrode pin is provided with a closed cavity extending in the longitudinal direction and in which a hydrogen getter is present. The end of the electrode pin extending in the discharge vessel is formed by a metal part of a hydrogen-permeable metal which bounds the cavity.This construction provides a solution for the contradictory requirements which have to be imposed upon the arrangement of a getter with a hydrogen-permeable envelope. The construction furthermore provides a hydrogen getter with both a high reactivity and a great capacity.

Abstract: A high-pressure gas discharge lamp having a discharge vessel provided with an aggressive gas filling, and electrodes between which the discharge takes place during operation. A hydrogen getter is placed within the discharge vessel and it consists of a getter material surrounded by a hydrogen-permeable wall. The getter material comprises at least a material of the group yttrium, lanthanum, the lanthanides and alloys of the said elements. The hydrogen permeable wall comprises at least one of the elements chromium, molybdenum, tungsten, tantalum, nickel and iron.