The electrode assembly in each of the noble gas lamps is based on the same design employed for low pressure sodium lamps. In more recent years, quartz arc tubes have superseded original glass types on account of the fact that semi-mechanised equipment could be employed for their production. For this reason, the end chambers around the temperature electrodes are formed into bulbous regions to limit the glass temperature. The Helium lamp however dissipates a rather greater power than any of the others, and its discharge tube operates at a proportionately higher temperature. Originally all were fabricated in soft glass tubes. They employ a variety of different discharge tube styles over the years. These are Helium, Neon, Argon, Krypton and Xenon. In the 1940s a range of electric discharge lamps was developed to supersede these crude methods, and delivered much more stable results by virtue of the high purity and constant output.įive lamps make up the Noble Gas group in the Philips series. Both methods produce somewhat unstable results and require constant attention.

Atomic spectra were originally produced by creating an arc between electrodes fabricated of the metal to be studied, or by sprinkling a powdered salt into a gas flame. Spectral lamps find a home in laboratory applications where they are commonly employed as stable, high quality sources of discrete spectral lines.

Krypton atomic spectra