@article{JRC13154, address = {}, year = {1997}, author = {Hummel R and Krasenbrink A and Valisi M and Schwab S and Schaettgen F}, abstract = {The STORM project analyzes the deposition and resuspension of representative (SnO2, CsOH) aerosols in selected components (pipes, bends, steam generator) under reactor accident typical conditions. To model these phenomena a large and representative data base describing the aerosol behaviour is required. To obtain real-time and on-line information of the airborne aerosols optical instruments are applied. The three wavelength extinctiometer is one of them. The instrument (EXM, Grimm 3900) is based on the attenuation of laser light of three different wavelengths. From the differences in attenuation not only the concentration but also a medium particle size are derived. To overcome the difficulties of relating mass-based and optically measured particle parameters the instrument has been intercalibrated in a separate test rig using different aerosols (parameters of choice: material, size, concentration, shape) characterizing the aerosol in parallel with the EXM, impactors (Andersen Mark III) and filters. The results of the year-long intercalibration excercise is documented using different examples. Afterwards the instrument has been employed in the STORM experiments which have been running since September 1995. Several of the experiments will be discussed in view of the performance of the EXM. Finally, the strengths and weaknesses of the instrument are summarized and a safe procedure for its use in aerosol experiments described. }, title = {Application of a Three-Wavelength Extinction Meter within the STORM Experimental Programme}, type = {}, url = {}, volume = {}, number = {}, journal = {Journal of Aerosol Science}, pages = {}, issn = {}, publisher = {}, doi = {} }