Nernst lamp

The Nernst lamp (also Nernst lamp) was invented by physical chemists Professor Walther Nernst in Göttingen in 1897. This bulb was more efficient than the then common carbon filament lamp and also provided a more natural, more similar to daylight light. For the filament ( Nernststift ) mixtures of zirconia and yttria were used.

In contrast to the carbon filament lamp, the Nernst lamp did not require a vacuum ( or inert gas, such as in the subsequent metal filament lamp), but could (or even had ) are operated in air. The electrical conductivity is not due to electron as metals, but on ion conductivity of two negatively charged oxygen ions. However, this conductivity is only at high temperatures, so that the filament of the Nernst lamp had to be first preheated, for simple models with a match or a spirit burner, with comfortable models with an electric heater ( heating coil made of platinum). It took about half a minute, to the incandescent body was sufficiently conductive to be held by the current flow by itself to a high temperature. The operating temperature of the lamp is about 1600 ° C. The life of the glow pencil was given as about 700 hours that the heating wire with about 2000 hours.

Nernst sold his patent to the AEG (Director Emil Rathenau ). The Nernst lamp was manufactured by AEG in Berlin and Westinghouse ( Nernst Lamp Company ) in Pittsburgh. She was presented with great success at the World Exhibition in Paris in 1900. Around 1910 it was replaced by metal filament lamps according to the principle of today's incandescent bulbs but had initially advantages when operating at high voltages ( 220 V ), since first no sufficiently thin metal wires could be (eg tungsten ) were prepared.

For special applications, particularly as a source of radiation in the infrared spectroscopy, Nernststifte were used until the 1990s by default. It shows a very favorable spectral energy distribution because of its high operating temperature of 1900 K in the mid-IR region.

Trivia

Students compacted in view of the features of their lecture hall with Nernstlampen Schüttelreim following: "Whether you also sits by the light of the Nernstlichts, it does not help you, my son, you will learn nothing. "