Molter, D. Theuer, M. Jonuscheit, J. Torosyan, G. Beigang, R.
Die Terahertz-Spektroskopie mit breitbandigem, gepulsten Terhertz-Quellen und einer kohärenten Nachweistechnik eröffnet viele neue Möglichkeiten zur Untersuchung von Gasen, Flüssigkeiten und Festkörpern. Durch Vereinigung der Eigenschaften benachbarter Frequenzbereiche (Mikrowellen und Infrarot) können völlig neue Messverfahren eingesetzt werden. D...
Herbst, J. Scherer, B. Lambrecht, A.
Fraunhofer IPM entwickelt Gasanalysatoren auf Basis der Laserabsorptionsspektroskopie für Anwendungen in der Prozessmesstechnik und Raumluftüberwachung. Es wird die Entwicklung eines Prozessgasanalysators für Acetylen in einer komplexen Gasmatrix vorgestellt. Für das Spektrometer auf Basis eines Quantenkaskadenlasers (QCL), der im Bereich von 14 μm...
Lambrecht, A. Kostal, P. Tacke, M. Büchermann, W. Kürbitz, G.
This paper investigates the potential of infrared detector arrays for passive gas detection systems. At present, extractive methods are commonly used for the detection of gases and vapours. In case of large distances or in the open atmosphere remote measurement systems have to be employed. Remote detection can be used to monitor industrial and traf...
Wörner, R. Grisar, R. Tacke, M.
A compact optical gas analyzing system with a diode laser operating at 1.3 Mym wavelength for hydrogen fluoride detection is described. Pulsed integrative spectroscopy is used as the signal processing technique. A detection limit below 10 ppm was obtained for a 10 cm optical path.
Tacke, M.
Diode lasers are used in environmental analysis for the immission detection of trace gases at the ppb level with temporal resolution of some minutes as well as for emission studies with millisecond response times. The fundamentals of these applications are described.
Slavik, J.
The main features of an evaluation method for signals from sensors for the quantitative analysis of gas mixtures are described. The sensors are assumed to be non-selective and non-linear, with no physical model of their operation available. The method can easily be generalized to more than two gases or sensors without becoming unduely expensive. Pr...
Bessey, E. Schottka, P. Pelz, N. Grisar, R. Klocke, U. Knothe, M. Riedel, W.J. Wolf, H.
We report on a four-component TDLS system for highly sensitive real time car exhaust gas analysis, based on infrared diode laser absorption spectroscopy. Four lead-salt diode lasers, one for each gas species, are operated simultaneously in a fast multiplex mode. A long optical path of up to 100 m in a multiple reflection arrangement and a short pat...
Grisar, R. Klocke, U. Riedel, W.J. Wolf, H. Wißler, R.
We report on the dynamic car exhaust gas analysis with single ignition cycle resolution. The optical setup using pulsed integrative IR diode laser spectroscopy as well as the fast sampling system are described. Preliminary NO and CO measurements on a one cylinder engine with a time resolution in the ms range are presented.
Grisar, R. Riedel, W.J. Wolf, H. Wißler, R.
We report first results of car exhaust gas monitoring with time resolution in the millisecond range using tunable lead salt diode lasers and a fast heating gas sampling system with a low pressure optical cell.
Grisar, R. Tacke, M.
Laser haben in vielen Bereichen der Meßtechnik Bedeutung erlangt. Dabei sin d die Grundlagen der Meßverfahren fast immer ähnlich. Man beobachtet nämlich meist Reflexion, Absorption oder Streuung von Licht. Problemstellungen und Aufbauten sind aber sehr unterschiedlich. Außer aufwendigen Einzelentwicklungen, in denen z.B. Riesenimpulslaser in radarä...