Darmstadt 2008 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

UP: Fachverband Umweltphysik

UP 6: Poster: Atmosphäre und Aerosole: Instrumentelles und Laboruntersuchungen

UP 6.1: Poster

Dienstag, 11. März 2008, 16:30–19:00, Poster B1

Recent advances in the application of light-emitting diodes as light sources in active DOAS measurements — Holger Sihler, •Christoph Kern, and Ulrich Platt — Institute of Environmental Physics, Heidelberg, Germany

The Long Path Differential Optical Absorption Spectroscopy (LP-DOAS) technique is a well established method for measuring atmospheric trace gases. The application of light-emitting-diodes (LEDs) as artificial light sources represent a very advantageous alternative to common xenon-arc lamps. LEDs are smaller, lighter, cheaper, more durable and less power consuming.

Now, measurements in the deep ultra-violet wavelength range became possible due to recent developments of UV-LEDs based on III-nitride semiconductor materials. Their first application in active DOAS measurements is presented. The trace gas concentrations of SO₂, O₃, NO₂, and CH₂O were measured in the wavelength range between 297 and 309 nm.

Furthermore, a compact active DOAS instrument was built, which is entirely battery powered, and therefore well-suited for field measurements in remote areas. As an example, preliminary results of measurements in the plume of Masaya Volcano, Nicaragua, are given.