Determination of Nox and soot concentrations using a multi-wavelength opacimeter

H. Axmann*, A. Bergmann, B. Eichberger

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review


    A novel approach to measure both the particle and the NO2 concentration in the exhaust of diesel engines during the roadworthiness test in the periodical technical inspection is presented. It is based on a multi-wavelength extinction measurement and a mathematical inversion algorithm to obtain the concentrations from the extinction readings. Such individual concentration values can deliver valuable insight into the cause of engine or exhaust aftertreatment defects. Furthermore the extended opacimeter provides future-proofness, if nitrous gas emissions are incorporated in the roadworthiness regulations. In addition to a detailed description of the multi-wavelength approach this chapter provides an overview of particle and nitrous gas emissions by diesel engines, the related legislation, the extinction measurement using standard opacimeters, and the physical background for this optical measurement method. The applicability of the multi-wavelength method is derived mathematically and validated with first experimental results as well as with simulations.

    Original languageEnglish
    Title of host publicationSmart Sensors, Measurement and Instrumentation
    PublisherSpringer International Publishing AG
    Number of pages19
    Publication statusPublished - 2017

    Publication series

    NameSmart Sensors, Measurement and Instrumentation
    ISSN (Print)2194-8402
    ISSN (Electronic)2194-8410


    • Diesel particles
    • Light extinction
    • Multi-wavelength measurement
    • Nitrogen dioxide
    • Opacimeter

    ASJC Scopus subject areas

    • Computer Science (miscellaneous)
    • Electrical and Electronic Engineering
    • Mechanical Engineering
    • Instrumentation

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